Contents

Episode 33: Aphids & Fruit Trees

Aphids are tiny, but never underestimate the damage they can do to your fruit trees and fruiting shrubs. You could try to get rid of them by spraying your entire tree with insecticidal soap. But you may have to apply it a number of times and if your tree is large, that’s going to be a lot of work.

Or you can get others to do the work for you! In this episode of The Urban Forestry Radio Show and Podcast we learn about aphid eating insects. We will explore when and how to bring them into your garden or orchard and when to keep them away!

Our guest is entomologist Stephen A. Marshal, who teaches entomology at The University of Guelph in Ontario. He’s also the author of the classic tome Insects: Their Natural History and Diversity. And he has just completed a new book Beetles: the Natural History and Diversity of Coleoptera

  • Stephen A. Marshall, Author, “Insects: Their Natural History and Diversity”
  • Insects: Their Natural History and Diversity

During the live show Stephen answers listener questions and comments. The conversation continues on OrchardPeople.com’s facebook page.

The host of the Urban Forestry Radio Show and Podcast is Susan Poizner of the award-winning fruit tree care education website www.orchardpeople.com (GWA Silver Award of Achievement 2016) and the author of the award-winning fruit tree care book Growing Urban Orchards (GWA Silver Award of Achievement 2014). You can listen to previous episodes of The Urban Forestry Radio Show and Podcast at www.orchardpeople.com/podcast and you can subscribe to the iTunes podcast.

Tune into The Urban Forestry Radio Show LIVE by going to RealityRadio101.com on the last Tuesday of every month at 1.00 pm Eastern Time and email your questions in during the show to This show covers fruit trees, food forests, permaculture and arboriculture.

To listen to the archived podcast now, click on the sound file below. Enjoy!

Photo Credits: Photos from “Insects: Their Natural History and Diversity” by Stephen A. Marshall (Valued at $95.00)

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Aphids you hate them! But the question is – How to get rid of aphids?

Those pesky, troublesome pests we find on plants in the landscape and on houseplants that go by other names as well:

  • Plant Lice
  • Plant Louse
  • Greenflies
  • Blackflies
  • Whiteflies – different than true whiteflies

Plants even get Aphid attached to their name like the:

  • Wooly Aphid or Wooly Apple Aphid
  • Red Aphid
  • Milkweed Aphid
  • Russian Wheat Aphid
  • Oleander Aphid
  • Hibiscus Aphid – Check your Hibiscus bush and tree
  • Potato Aphid (Macrosiphum euphorbiae)
  • Benchmade Aphid
  • Soybean Aphid
  • Cabbage Aphid (Brevicoryne brassicae)
  • Cotton Aphid
  • Green Peach Aphid (Myzus persicae)
  • Pea Aphid
  • Melon Aphid (Aphidius colemani)
  • Cherry Oat Aphid (Rhopalosiphum padi)

The Common Names of Insects Database at the Entomological Society of America website entsoc.org list over 100 different species along with their more common names.

What Color Are Aphids?

With numerous species, one picture of an aphid may look different than another.

These small and tiny (size wise about 1/8 of an inch and oval in shape), lice-like insects, with pear-shaped bodies and long antennae come in a variety of colors: light green, pink, white, brown, red aphids, yellow-gray, gray and black aphids.

Where Do Aphids Live?

You’ll find aphids of all kinds living on the young, tender tips of new developing growth, on the undersides of leaves and clustered or in colonies on stems. There are even root aphids!

These garden pests are most active during springtime as temperatures warm and new tender growth emerges.

Some aphids live only on one host plant. Others will thrive on many different garden plants.

For example, Macrosiphum rosae aphids on roses while cinara aphids feed and live on conifer and cypress trees.

All come equipped with delicate, tuber-like piercing, sap-sucking mouth parts.

These small sap-sucking insect pests pierce through the outer tissues of the plant.

They suck out and ingest the fluids and plant sap juices which are full of nutrients from new tender growth and stems.

The feeding aphids distorts new growth, sometimes causes leaves to curl and leaves a sticky residue on plant leaves.

This deprives the plant of the fuel and nutrition it needs to survive and thrive. As a result, plants lack vigor and stunted growth.

In addition to depleting a plant’s resources, aphids also carry viruses. These viruses can infect plants and can wipe out entire crops.

Grains, potatoes (potato leafroll virus) and citrus fruits are especially susceptible to viruses carried by aphids.

Related Reading: Controlling Aphids on Succulents

Killing Aphids

Aphids live and work in colonies, are usually wingless and easy to control. Winged aphids can cause a real problem since they can spread so rapidly within days.

Even though aphids multiply rapidly, they move slowly from plant to plant. They like anything green.

Life Cycle Of Aphids

According to the University Of California, aphids have many generations a year. Adult females give birth to live offspring without mating and bypass the egg stage known as parthenogenesis,

Young aphids called nymphs, molt, shed their skin about four times before becoming adults. In some cases, aphids lay these eggs on an alternative host plant, usually a perennial plant, for winter survival.

When the weather is warm, many species of aphids can develop from newborn nymph to reproducing adult in seven to eight days.

Because each female adult aphid can produce 12 offspring per day up to 80 offspring in a matter of a week, aphid populations can increase rapidly.

Aphid Control

You can control “all” aphid species without much difficulty.

A good contact insecticide chemical (Malathion, horticultural oil) or organic aphid control spray (like this Neem spray or this commercial insecticidal soap by Safer both natural aphid spray killers will kill them on contact.

When insecticides come in contact with the pest it will kill aphids by stopping or blocking the breathing pores.

To get rid of aphids, you may need to repeat applications three times to kill the aphid eggs as they hatch. Keep your eyes peeled, as eggs are airborne, you may need to re-apply treatments.

If a commercial insecticidal solution is not available, try a simple “homemade aphid spray” – 3-4 tablespoons of liquid soap (like castile soap) per gallon of water and apply as a foliar spray to your plant.

Make sure to thoroughly spray the underside of the leaves as well. Soap is effective in managing aphids, safe for people and the environment.

However, I like all-natural Neem Oil which I’ve found very effective in controlling aphids.

Keep on the lookout for ants. Aphids and ants go together. Aphids excrete a sweet sticky substance known as honeydew. Ants are attracted to this and will keep aphids as “livestock” to maintain a steady supply of honeydew.

Honeydew not collected by ants tends to accumulate on the plant surface causing a “black sooty mold fungus” and a barrier to sunlight.

This interferes with photosynthesis and further compromises your plants’ health and ability to survive.

Is It Possible To Eliminate Aphids?

To eliminate aphids completely, you would need to broadcast poison all over your garden. This would be detrimental to beneficial fauna, natural predators, and you.

Instead of doing away with them altogether, it is preferable to keep your aphid population under control.

This is a project you must stay on top of because aphids reproduce quickly if left unchecked.

However, for more advanced infestations, certain essential oils, neem extract, solutions of insecticidal soaps or even plain old soap and water may do the trick.

For many homeowners, natural aphid control is the preferred method to take. Let’s explore over a dozen different ways you can control aphids naturally.

Aphids are a big problem for gardeners and farmers of all types.

There are more than 4000 different species of aphids. Of these, 250 types are very damaging to crops.

14 Organic Ways – How To Get Rid Of Aphids Naturally

#1 – Pick The Aphids Off!

If you notice a few aphids on your plants, pick them off right away. If you have a minor infestation this may be all you need to do.

If you have quite a few aphids, you’ll want to put on a pair of close-fitting gloves to pinch them off and brush them away.

#2 – Remove Affected Plants

Home remedy for aphids:

If your aphid infestation only has an impact on a few branches or a few plants, remove these. Keep individual plants quarantined and begin killing aphids with soapy water.

If you have pruned away a few infested branches, put them in a bucket of soapy water for aphids to soak and kill off the aphids. Alternately, if you have a burn pile you might want to burn these branches.

Removing the food source of the aphids and any garden pest is key to pest control. No food – no Eat!

#3 – Hose Them Down!

With established plants, a vigorous blast of water from a garden hose can knock off small aphid infestations. This is a good follow-up after picking individual aphids off mature plants.

Blasting small or young plants with water is not a good idea as it may damage or kill them.

#4 – Spray Them With A Dish Soap!

Dish soaps dissolve the waxy coating protecting aphids’ bodies. With this coating gone the pests become dehydrated and die very quickly.

You don’t have to make a strong insecticidal soap solution. Just a couple of tablespoons of dishwashing liquid in a quart of water sprayed directly on the aphids will kill them.

Be careful about spraying this solution everywhere because it will also kill good insects along with any natural enemy and aphid predators such as the ladybug, praying mantis and the like.

Use it only specifically on aphid infestations you can see.

#5 – Neem Insecticide Oil

Neem oil is a natural antifungal, antibacterial and insecticidal oil that can be added to your soap concoction or used instead of dish soap in the same way.

It not only kills aphids, it also repels them.

Organic Natural Neem Oil

Neem oil is our favorite go-to natural insecticide. Unfortunately, like the soaps it is unfriendly to good garden bugs so use it sparingly. Learn more about How to use Neem oil on plants and its many benefits here. You can also purchase Neem at Amazon.

#6 – Essential Oils For Aphids Can Also Be Used In Much The Same Way As Neem Oil And Dish Soap

Use essential oils by adding half a dozen drops each of rosemary, thyme, peppermint and clove oils to a quart of water to make an excellent aphid killing, spider mite killer and repelling spray.

As a bonus, you can also spray this on yourself to repel insects such as mosquitoes.

Read more on: Getting rid of spider mites organically

#7 – Maintain A Healthy Population Of Beneficial Insects

When you have reduced your aphid population, try introducing some beneficial ‘bugs’ to your garden.

You can purchase ladybugs or lady beetles (hippodamia convergens) online and sometimes from your local garden center.

Natural predators like green Lacewings (sometimes called aphid lions) eat aphids, and you can purchase them or their eggs to populate your garden.

Aphid midge larvae are voracious aphid killers. A single larva can eat 65 aphids per day. Their strong jaws and paralyzing toxin help reduce aphid populations.

Hoverfly larvae maggots consume hundreds of aphids and other soft-bodied insects such as scale insects and thrips.

Parasitic Wasps lay eggs in aphid colonies. As the wasps’ larvae hatch, it slowly weakens and kills the aphids. And the aphids as the wasps pupate become an “aphid mummy.”

You can also naturally attract beneficial predator insects to your garden by planting fragrant herbs throughout the garden. Some of the best choices include:

  • Oregano
  • Yarrow
  • Fennel
  • Garlic
  • Catnip
  • Clover
  • Mint
  • Dill

Be advised if you have cats or if cats roam your neighborhood; you should leave the catnip out of this mix!

#8 – Repel Aphids With Plants

Just as you can attract beneficial insects to your garden with fragrant herbs, you can repel aphids with plants such as garlic and onion.

Create your own garlic spray for aphids at home.

As a bonus, the flowers of these plants will also attract beneficial garden insects.

#9 – Keep The Ants Away!

As we have said, honeydew attracts ants, and they tend to be very protective of their aphid herds.

Ants may even interfere with birds being able to eat aphids, so it’s a good idea to prevent them ever discovering there are aphids on your plants.

You can do this by distracting them with baited traps on the ground and at the base of infested plants.

A jar lid containing a few drops of honey or sugar water should do the trick.

#10 – Create A Habitat For Birds!

Remember having a healthy bird population in your garden is a good way to keep the insect pests down. This includes aphids!

The best birds for eating aphids are small ones such as titmice, chickadees and wrens. Attract them by providing bushy hedges and small trees for them to nest and hide in.

Some good choices include hydrangeas, privet hedge, and boxwood plants.

Place birdhouses strategically and provide birds with foods such as shelled or black oil sunflower seeds to attract them and keep them present so they will also eat your aphids!

#11 – Distract The Aphids!

Along with all of your other strategies, you might also plant a decoy garden to draw the aphids away from your other plants.

A lovely, colorful garden of asters, the cosmos plant, dahlias, and zinnias is sure to draw aphids!

You can follow the ants’ example and cultivate your aphids in this area so there will always be plenty of good food for your bird population.

Additionally, you should be advised that these plants should not be intermixed with your other plants as they will tend to increase your aphid problem.

#12 – Keep Your Plants Healthy!

Be sure you understand the care requirements for all of the types of plants you grow. Strong healthy plants naturally repel aphids and disease.

#13 Control Garden Pests With Diatomaceous Earth

Food-Grade Diatomaceous Earth is very pest control solution on soft-bodied insects like aphids. The fine-powder slices the outer layer of the aphids soft-body as they crawl on the DE killing the pest through dehydration.

#14 – Spray A Cayenne Pepper Mix

Use cayenne pepper to control aphids and other small garden pests

In one cup of water mix one teaspoon of Cayenne pepper or blend one hot Chile Pepper in one cup of water.

Spray and cover the insect pests with the cayenne pepper spray solution

Stay In Balance!

Learn from the balance of nature. Aphid pest control is not a one-step process.

While you could spray a systemic insecticide all over your yard and kill these soft-bodied insects off, they would simply come back again when the poison wears off.

It is far wiser to create a balance by targeting aphids when you see them, cultivating a good population of beneficial insects and birds and creating distractions to keep the aphids away from your most prized plants.

2 Homemade Aphid Sprays For Vegetables And Plants

Organic gardeners have used homemade sprays in fighting and controlling aphids and mealybugs for generations. Below you’ll find two DIY organic aphid sprays made from tomato leaves and another from garlic.

Knowing how to make and use these sprays use is important, but understanding why they work is equally important. Check out these two organic, homemade aphid sprays.

Organic Aphid Spray Made With Tomato Leaves

The tomato plant a nightshade family member contains alkaloids – a toxic compound found in their leaves.

Chopping the leaves releases the alkaloids. When diluted and suspended in water, they make an easy-to-use homemade spray for fighting aphids. A spray safe for the environment, plants, and humans.

Making The Tomato Leaf Spray

  • 1-2 cups of tomato leaves
  • Cheesecloth or a strainer
  • Two cups of water
  • Spray bottle

To make the spray, soak 1 or 2 cups of chopped tomato leaves overnight (depending on the concentration you require) in two cups of water.

Using the fine strainer or cheesecloth strain the leaves out of the mixture. Add two additional cups of water and add it all to the spray bottle.

Applying The Tomato Aphid Leaf Spray

When battling aphids completely spray the foliage and stems of infested plants. Make sure to cover the undersides of the leaves as aphids congregate in those areas.

Caution: While safe for plants and humans, some people are allergic plants in the nightshade family. If you’re allergic to them take care when applying this homemade aphid spray.

Aphid Garlic Oil Spray

As a pest-fighting spray garlic mixtures have been used for many years. Garlic contains sulfur which is antifungal and anti-bacterial but also toxic to most pests. When combined with dish soap the mixture breaks down soft-bodied pests.

Making A Garlic Oil Spray

  • 3-4 cloves of garlic
  • Cheesecloth or strainer
  • Mineral oil
  • Spray bottle
  • Water
  • Liquid dish soap (I like Castile soap)

To make the spray, finely chop or mince all the cloves of garlic and add the garlic to 2 teaspoons of mineral oil. Allow the mixture to sit for 24 hours before straining the mixture.

In one pint of water add the remaining liquid. When spraying, mix two tablespoons of the concentrate to 1 pint of water in the spray bottle

Applying The Garlic Oil Spray

Conduct a test-spray in a small area on one part of a plant to make sure the spray does not injure the plant.

If you don’t notice any damage or yellowing of leaves after a day or two, you ahead and spray the entire plant while paying close attention to the undersides of the leaves.

Caution: By being a non-selective insecticide, garlic oil can harm beneficial insects such as ladybugs.

Therefore, used it where no beneficial insects “live” in your garden.

These organic gardening sprays are effective, low in cost and safe for the environment.

Battling aphids is an ongoing process in the landscape and garden. However, scouting out for them and taking action quickly will reduce the impact they can have on your plants.

Hackberry Psyllids and Other Jumping Plant Lice

ENTFACT-413: Hackberry Psyllids and Other Jumping Plant Lice | Download PDF

by Lee Townsend, Extension Entomologist
University of Kentucky College of Agriculture

Psyllids are aphid‑like insects that resemble miniature cicadas. Also called jumping plant lice, these tiny insects have hind legs that allow them to jump and fly away quickly if disturbed. Large swarms may be seen on sunny, warm autumn afternoons but the insects usually disappear after a killing frost. Psyllids are attracted to light colored surfaces and clothing, those that land on people can be a temporary nuisance. The tiny sap feeders may probe the skin, giving a small bite sensation but they do not feed on humans or pets.

Hackberry Psyllid Hackberry Galls

Many psyllid species spend the winter in cracks and crevices of tree bark. They are attracted to lights and may enter through window screens or small cracks and crevices but generally do not survive for very long indoors and do not attack house plants, stored products, or furnishings.

Hackberry psyllids develop on hackberry trees, causing distinct raised or swellings or galls on the leaves. Egg-laying occurs over a period of several weeks beginning when new leaves unfold from the bud. These psyllids stimulate abnormal growth of leaf cells causing formation of the gall in which the insects live and feed. The gall provides food and protection from many natural enemies. Infested hackberries do not seem to be harmed by the galls but severe infestations may cause early leaf drop. Other species have similar life cycles but develop on other host plants.

Management

Psyllids are usually held in check by natural enemies. Outbreaks can occur in some years resulting in temporary annoyance but aggressive control measures are not warranted nor are effective control measures available. Several applications of an insecticide would generally be necessary to keep an insecticide residue on the expanding leaves during the entire period that eggs are hatching. Spraying of large trees is difficult and without powerful sprayers, it is difficult to get the good coverage that is needed. If chronic problems occur, removal of the source plants may be worthwhile.

Revised: 11/12

CAUTION! Pesticide recommendations in this publication are registered for use in Kentucky, USA ONLY! The use of some products may not be legal in your state or country. Please check with your local county agent or regulatory official before using any pesticide mentioned in this publication.

Of course, ALWAYS READ AND FOLLOW LABEL DIRECTIONS FOR SAFE USE OF ANY PESTICIDE!

Images: University of Kentucky Entomology.

Aphids Tree Disease – How To Treat Tree Aphids And Honeydew Dripping

When you see tree leaves dripping sap, the usual cause is tree aphids. These pesky insect pests can cause serious stress to your trees and lead to disease. Learn more about aphids on tree limbs and foliage and what you can do for tree aphid treatment.

What are Tree Aphids?

These tiny, soft-bodied, pear-shaped insects can be almost any color. Aphids on tree foliage and shoots feed by sucking fluid from the tree through a slender mouthpart called a proboscis. They feed in clusters, usually on the undersides of leaves near the point where the leaf attaches to the stem, or on tender young shoots and buds. As they feed, they secrete a sticky fluid called honeydew. When enough aphids are feeding on the tree, this honeydew will begin dripping from the leaves.

Aphids Tree Disease Issues

Some tree diseases are spread by aphids, especially fungal diseases. Tree disease is much more serious than aphid infestations, and can kill or seriously damage a tree. To prevent the spread of aphid tree disease, keep the tree as healthy as possible to support its natural defense against disease and control the aphids as much as possible.

Tree Aphid Treatment

The first step in controlling aphids is to control the ants that feed on the honeydew they secrete. Ants protect aphids from their natural enemies to ensure a continued supply of honeydew. Bait traps are effective, but read the label carefully, and only use traps that are safe around children, pets and wildlife.

Tree aphids have a number of natural enemies that help keep their populations in check. When trying to control aphids, keep in mind that you want to preserve these beneficial insect populations. Beneficial insects are much more effective at controlling aphids than insecticides, and the use of strong insecticides can make aphid infestations worse.

You can remove aphids from small trees with a strong spray of water from a hose. Aphids that are knocked off of a tree are unable to return. Spraying the tree with neem oil or insecticidal soap helps control aphids without harming beneficial insects, but the spray has to come into direct contact with the aphid to be effective. Spray the tree until the insecticide drips from the foliage. It may take several applications to eliminate the aphids.

Insecticides that contain ingredients such as permethrin, acephate, malathion, diazinon, or chlorpyrifos are effective against aphids, but they are also effective against beneficial insects and may only make the problem worse. Use them only as a last resort.

Now that you know a little about what causes tree leaves dripping sap, you can take the correct steps in preventing and treating aphids on tree foliage.

There are approximately 4,000 aphid species found throughout the world. Low to moderate numbers are usually not harmful to plants and rarely require control. However, heavy infestations will cause leaves to curl, wilt or yellow and stunted plant growth. A general decline in overall plant vigor will also be noticed. Several species can transmit plant diseases, particularly viruses which they pass on during feeding.

Identification

Aphids are small (1/8 inch long), soft bodied, pear-shaped insects that may be green, yellow, brown, red or black in color depending on species and food source. Generally adults are wingless, but some can grow wings, especially if populations are high. They have two whip-like antennae at the tip of the head and a pair of tube-like structures, called cornicles, projecting backward out of their hind end.

Note: As they feed, aphids secrete large amounts of a sticky fluid known as honeydew. This sweet goo drips onto plants, attracting ants and promoting a black sooty mold growth on leaves. Cars and lawn furniture that are under infested trees will also be covered with this sticky fluid.

Life Cycle

In spring wingless female aphids hatch from overwintering eggs and soon give birth to many nymphs (males are not present). Young nymphs increase gradually in size and within a week give birth to many more nymphs. This process is repeated several times and results in huge population explosions. As the colony grows, a few of the females develop wings and fly off to other host plants to start new colonies. In late summer and early fall sexual forms (males and females) develop which mate and lay overwintering eggs. There are many overlapping generations per year.

Note: Most aphids, except for the sexual forms, do not have to mate in order to reproduce, and they produce live young, rather than eggs.

How to Control

  1. Pinch or prune off heavily infested leaves or other plant parts.
  2. Use the Bug Blaster to hose off plants with a strong stream of water and reduce pest numbers.
  3. Commercially available beneficial insects, such as ladybugs and lacewing are important natural predators. For best results, make releases when pest levels are low to medium. If populations are high, use a least-toxic, short-lived natural pesticide to establish control, then release predatory insects to maintain control.
  4. Apply 100% organic Diatomaceous Earth for long-lasting protection. Made up of tiny fossilized aquatic organisms, that look like broken glass under the microscope, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains NO toxic poisons!
  5. Safer® Soap will work fast on heavy infestations. A short-lived natural pesticide, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within hours. Apply 2.5 oz/ gallon of water when insects are present, repeat every 7-10 day as needed.
  6. BotaniGard ES is a highly effective biological insecticide containing Beauveria bassiana, an entomopathogenic fungus that attacks a long-list of troublesome crop pests – even resistant strains! Weekly applications can prevent insect population explosions and provide protection equal to or better than conventional chemical pesticides.
  7. Made for use indoors or out, Bon-Neem is a unique blend of potassium soaps derived from Indian Neem tree seed and other natural sources. Specially formulated as a ready-to-use spray that kills most insect pests on contact.
  8. Horticultural oils should be applied early in the season or late in the fall to destroy overwintering eggs.
  9. Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
  10. Do not over water or over fertilize – aphids like plants with high nitrogen levels and soft new growth. Use organic fertilizers which release nutrients slowly.

Tip: Ants feed on the honeydew that sucking insects produce and will protect these pests from their natural enemies. An application of Tanglefoot Pest Barrier to the stalks of roses and other woody plants will help keep ants away.

Aphids

ENTFACT-103: Aphids | Download PDF

by Lee Townsend, Extension Entomologist
University of Kentucky College of Agriculture

Aphid Infestation

Aphids are soft-bodied insects that use their piercing sucking mouthparts to feed on plant sap. They usually occur in colonies on the undersides of tender terminal growth. Heavily-infested leaves can wilt or turn yellow because of excessive sap removal. While the plant may look bad, aphid feeding generally will not seriously harm healthy, established trees and shrubs.

However, some plants are very sensitive to feeding by certain aphid species. Saliva injected into plants by these aphids may cause leaves to pucker or to become severely distorted, even if only a few aphids are present. Also, aphid feeding on flower buds and fruit can cause malformed flowers or fruit.

Sooty Mold

Aphids produce large amounts of a sugary liquid waste called “honeydew”. The honeydew that drops from these insects can spot the windows and finish of cars parked under infested trees. A fungus called sooty mold can grow on honeydew deposits that accumulate on leaves and branches, turning them black. The appearance of sooty mold on plants may be the first time that an aphid infestation is noticed. The drops can attract other insects such as ants, that will feed on the sticky deposits.

Some aphids are very important vectors of plant viruses. However, it is seldom possible to control these diseases by attempting to kill the aphid vectors with an insecticide. Aphids carrying viruses on their mouthparts may have to probe for only a few seconds or minutes before the plant is infected. Resistant varieties or sequential plantings may be helpful in reducing problems with some viruses that attack annual plants.

HOW THE PROBLEM STARTS

Infestations generally result from small numbers of winged aphids that fly to the plant and find it to be a suitable host. They deposit several wingless young on the most tender tissue before moving on to find a new plant. The immature aphids or nymphs that are left behind feed on plant sap and increase gradually in size. They mature in 7 to 10 days and then are ready to produce live young. Usually, all of them are females and each is capable of producing 40 to 60 offspring. The process is repeated several times, resulting in a tremendous population explosions. Less than a dozen aphid “colonizers” can produce hundreds to thousands of aphids on a plant in a few weeks. Aphid numbers can build until conditions are so crowded, or the plant is so stressed, that winged forms are produced. These winged forms fly off in search of new hosts and the process is repeated.

CONTROL

Early detection is the key to reducing aphid infestations. The flight of winged colonizers cannot be predicted, so weekly examination of plants will help to determine the need for control. Examine the bud area and undersides of the new leaves for clusters or colonies of small aphids. The presence of these colonies indicates that the aphids are established on the plants and their numbers will begin to increase rapidly. Small numbers of individual colonies on small plants can be crushed by hand or removed by pruning as they are found. In some cases, this may provide adequate control. If aphid colonies can be found on about 5% or more of foliage tips of a plant or planting, then a control measure should be considered. Most products used for aphid control work as contact insecticides. This means that the aphids must be hit directly with spray droplets so that they can be absorbed into the insect’s body. Since aphids tend to remain on the lower leaf surface, they are protected by plant foliage. Thorough coverage, directed at growing points and protected areas, is important. It is difficult to treat large trees because of the high spray pressure necessary to penetrate the foliage and to reach the tallest portions of the tree. Hose-end sprayers can be used on 15 foot to 20 foot trees but they need to produce a stream rather than an even pattern to reach these levels. Skips in coverage are common and there is a significant potential for applicator exposure through drift and runoff. Commercial applicators may have the necessary equipment but these treatments may be very expensive. Aphid control is rarely feasible in these situations.

Summer oils can be used against aphids on some types of trees and ornamental plantings. They kill by suffocating the insects and/or disrupting their membranes. Check the label for cautions on sensitive plants; oils can injure the foliage of some plants. Weather conditions, especially high temperatures, can increase the potential for foliage burn. Do not spray dormant oils during the growing season. There is no residual effect so additional applications may be necessary.

Fatty acid salts or insecticidal soaps are very good against aphids. As with summer oils, they apparently work to disrupt insect cell membranes. They require direct contact with the insects and leave no residual effect.

Nervous system insecticides, such as malathion, Dursban (chlorpyrifos), and Orthene (acephate), are labeled for use on many shade trees and ornamental plants for aphid control. As with oils and soaps, coverage is very important and a follow-up application may be necessary. Be sure that the plant or crop that you are treating is listed on the product label. Sevin (carbaryl) is not effective against many aphids so it is generally not a good choice for control unless recommended specifically. In fact, applications of Sevin may reduce the number of beneficial insects, such as lady beetles, and increase the potential for aphid outbreaks.

WHAT HAPPENS IF NOTHING IS DONE?

Aphid control is most valuable for new plantings, where excessive sap removal is more likely to affect general plant vigor. Established and otherwise healthy plants can tolerate moderate to heavy aphid infestations, although affected leaves may wilt and turn yellow and there may be some premature drop.

Good cultural practices, such as watering and fertilization, will help to reduce stress by these insects. Problems with honeydew and sooty mold may develop but tend to be temporary and disappear after the aphids are gone.

A few aphid species produce cupped or distorted leaves; these plants may lose some of their esthetic appeal for the season. Once the distortion occurs, the leaves will remain cupped and twisted until they fall off. Usually, the infestation is not noticed until the injury has occurred. Insecticide applications often are less effective because the aphids are protected in the gnarled leaves.

Plants that become infected with an aphid-borne virus may be severely stunted and may die. Preventive sprays are rarely effective in keeping viruses out of plantings but they may reduce the spread within a group of susceptible plants.

NATURAL ENEMIES

Syrphid Fly Larva:
an important aphid predator

Beneficial insects, such as lady beetles and lacewings, will begin to appear on plants with moderate to heavy aphid infestations. They may eat large numbers of aphids but the reproductive capability of aphids is so great that the impact of the natural enemies may not be enough keep these insects at or below acceptable levels.

Revised: 1/00

CAUTION! Pesticide recommendations in this publication are registered for use in Kentucky, USA ONLY! The use of some products may not be legal in your state or country. Please check with your local county agent or regulatory official before using any pesticide mentioned in this publication.

Of course, ALWAYS READ AND FOLLOW LABEL DIRECTIONS FOR SAFE USE OF ANY PESTICIDE!

Photos courtesy USDA Insect and Plant Disease Slide Set and University of Kentucky Entomology

Sometimes I think that pests, like scales, aphids and mites adore my fruit trees as much as I do. They feast on the juicy tender plant parts in the warm summer and overwinter on my fruit trees. Dormant oil does help control these annoying little pests and homemade dormant oils are safe for use on fruit trees. Homemade dormant oils are easy to make at home and provide the same benefit as store bought dormant oils without the petroleum (because you choose the oil) and it is soooo much cheaper to make your own.

As recently as 10 years ago, dormant oils contained heavy petroleum based oils that had to be applied during fruit trees’ dormancy in order to prevent damage to their foliage and buds. Today, newer dormant oils are lighter, allowing them to be applied at anytime during the year without harming the tree’s buds. Because you can apply homemade dormant oil throughout the season, the term “dormant” is a bit of a misnomer now, but is still a benefit as you will see.

How Dormant Oil Works as an Insect Control

Dormant (or Horticultural Oil is usually combined with some type of emulsifying agent so that it can be mixed with water and used as a spray. The primary way horticultural oil kills insects is by suffocating them. The oil blocks the spiracles through which insects breathe.

Horticultural oils also disrupt the metabolism of insect eggs and the ability of some insects to feed, causing them to starve to death. Not a pretty picture, but remember that insects, like aphids, carry diseases from plant to plant by feeding.

Most commercial dormant oils contain kerosene or petroleum based oil that, when applied to trees, will smother overwintering insects like aphids, scales, mites, and their eggs or will dissolve their protective waxing coating. It is applied in the winter months when fruit trees are in their inactive period. (dormant) For dormant oil to provide proper control, the oil must come in contact with the pests. Dormant oils were further refined to produce lighter weight oils that can be applied during the growing season, without harm to many plants. When the term dormant oil is used now, it generally refers to the application timing, during the dormant season, rather than a type of oil.

Pests Controlled With Dormant Oil

  1. Adelgids: These small, sap-sucking insects are important pests in forests, landscapes, and Christmas tree plantations. Some are very difficult to control because of a waxy protective covering that they hide under.
  2. Aphids: sometimes called greenfly, are small insects that suck plant juices from stems and leaves and can severely stunt or even kill their host plants.
  3. Spider Mites: They are perhaps the most important agricultural and garden pests worldwide. Some researchers estimate that spider mites reduce total agricultural production by up to 5% each year.
  4. Thrips are tiny insects, most feed on leaves but some species are predators. Thrips feeding causes very distinctive silvery patches on the injured leaf. Thrips can be important pests in greenhouses because of the feeding injury as well as for a serious plant disease they can spread. Thrips, both plant-feeding and predatory species, also occasionally bite people. The bites are harmless but annoying.
  5. caterpillar eggs, leafhoppers, mealybug, scale, and whiteflies
    are the most common pests that call for the use of dormant oil.

I did NOT know this and I haven’t tried it, but dormant oil is also effective against powdery mildew. The popular homemade baking soda recipe (recipe one below) includes horticultural oil as an active ingredient.

Also, since horticultural oil is effective against aphids, which spread viruses by feeding on plants, it is also somewhat of a virus control.

Homemade Dormant Oil Recipes

This recipe is to control soft bodied insects like aphids, mites and mealybugs, all you need is an organic oil, laundry detergent and water. Mix together 1 tablespoon of any lightweight organic oil (again, I used sunflower), a few drops of laundry detergent and a quart of water. Shake well and pour into a spray bottle to use. This mixture controls insects by smothering them, so make sure to use an adequate amount when applying it to your fruit trees. (Oh, bonus!) I use this solution as a preventative also, It works by smothering insect egg casings.

I have tried several homemade “dormant oil recipes” and they do help control pests on fruit trees. The first recipe I used, and the most basic, was created by the scientists at Cornell University to controls over-wintering pests and fungal diseases.

Recipe One

Ingredients:

  • 2 tablespoons of ultra-fine canola oil (I don’t use canola oil for anything, I used sunflower oil here)
  • 1 tablespoon of baking soda
  • a gallon of water

Mix the oil and baking soda in the water and viola, homemade dormant oil!

The scientists at Cornell University also came up with a nourishing dormant oil you can make at home.

Recipe Two

Ingredients:

  • 2 tablespoons of any lightweight organic oil (again, sunflower oil)
  • 1 tablespoon of baking soda
  • 1 tablespoon of kelp
  • 1 tablespoon of mild dish soap
  • 1 gallon of water

Mix the first four ingredients together in the water and spray.

Recipe Three

Sometimes insect control on your fruit trees requires a different approach. Another method for controlling insects on fruit trees is to apply a spray that deteriorates the waxy outer coating of the insect, thereby exposing it to the elements, which causes its downfall. To make a dormant oil spray for fruit trees that accomplishes insect control via this method, Mix all the ingredients together. Pour the mixture into a sprayer and shake it vigorously before applying it. The baking soda and hydrogen peroxide are an important part of this homemade dormant oil because they work to sterilize fungal spores that are potentially damaging to fruit trees. This spray is also great for use after pruning as a way to seal the tree and keep unwanted pests out.

Ingredients

  • 2 tablespoons of baking soda
  • 5 tablespoons of hydrogen peroxide
  • 2 tablespoons of castile soap (which is made from an olive oil base)
  • 1 gallon of water

Dormant Oil for Fruit Trees

There is an oil defense especially for use with fruit trees.

  • 1 cup of vegetable oil
  • 2 tablespoons of liquid soap (preferably castile)
  • 1 gallon of water

The process is the same as in the above recipes… mix the oil and soap together in the water. Shake it good and keep shaking as you spray. This recipe is my “go to” I use for use when the tree is truly dormant. It suffocates insect eggs on my fruit trees. And as I mentioned above, many commercial dormant oil sprays contain petroleum based oils. This homemade mix provides a much less toxic substitution.

Applying Homemade Dormant Oil

All these dormant oil recipes are applied the same way. During the fruit tree’s dormancy (depending on your growing zone it will be any time the leaves fall or first frost and early spring before your fruit tree’s buds first open) Fill a pump sprayer with your homemade dormant oil and completely coat the fruit trees (stems and both sides of the leaves) with the mixture. Only apply the oil mixture when the fruit tree is dry. Moisture OR high levels of humidity will considerably lower the effectiveness of your dormant oil application. Note:

  • Dormant oils generally won’t harm beneficial insects since they are applied at a time when beneficial insects aren’t present on fruit trees and have a low toxicity level to humans and mammals.
  • Homemade dormant oils won’t leave a harsh residue behind.
  • It loses its ability to check pests once it is dry, and can harm plants susceptible to oil sprays.
  • Generally, the cedars, maples, spruce and junipers are susceptible tree species that dormant oil should not be used on.

When Not to Use Horticultural or Dormant Oil

  • You should only apply dormant oil on dormant deciduous trees or shrubs when the temperature is between 40-70°F in late fall and winter. Do not apply oils during freezing weather as this can cause the emulsion to break down and produce uneven coverage.
  • Do not apply oils if plant tissues are wet or rain is likely. These conditions inhibit oil evaporation. Dormant oil should not be used on evergreens.
  • Do not apply when fruit trees are stressed out. (e.g. from sun scald or bark splitting caused by late spring frosts – after growth has started – cool summer followed by a warm fall and drop in temperature, excessive or late season nitrogen fertilization, dry soil or root injury, frost cracking, excessive temperature fluctuations and drying winds, lack of snow cover all which stress a tree out) Stressed out trees are more likely to become more damaged by dormant oil than it is worth.
  • During extremely high temperature: Do not apply horticultural or dormant oil when temperatures are climbing high (esp. over 100° F. (38° C.) Drought-stressed plants are more susceptible to dormant oil damage.

  • Living With Bugs Jack DeAngelis, PhD OSU Ext. Entomologi
  • Cornell Horticulture
  • Department of Plant Pathology and Ecology The Connecticut Agricultural Experiment Station
  • Flanigan, Amada. Homemade Dormant Oil Spray for Fruit Trees
  • Colorado State University Extension: Insect Control: Horticultural Oils
  • Oklahoma State Extension Service – Dormant Oil

Strange Brew! Homemade Garden Sprays

In Permaculture we like to do things naturally, and we like to exercise our initiative to make use of the resources at hand to achieve our ends.

What better way to do this than to brew up your own DIY garden natural pesticides, fungicides, plant tonics and other such useful concoctions!

I’ve managed to gather a few recipes on my journeys, so I’ve gathered them here to share, so here they are. Enjoy, and safe brewing!!!

Organic White Oil

White Oil is an easy and inexpensive pesticide to prepare. It is used to control scale, aphids, mealy bug, citrus leaf miner, mites and caterpillars on roses, ornamentals, citrus and other fruit trees.

The commercial white oil insecticides sold in garden stores are petroleum based, making them quite expensive, and also the kind of thing you don’t really want to be spraying around your garden.

Traditional white oil is vegetable oil based and has been in use for around two centuries. If it worked all that time, it still works now!

How to Make White Oil

You will need:

  • 2 cups of vegetable oil
  • 1/2 cup pure liquid soap (use pure organic castile soap, made from olive oil if you want to keep it all natural)
  • Empty jar or wide-mouth bottle
  • Plastic spray bottle

Pour the vegetable oil and liquid soap into a bottle or jar and shake until the mixture turns white. This is concentrated white oil and to use it, it needs to be diluted with water.

To use, add 10ml per litre or water (two teaspoons per litre of water), put in a spray bottle, shake well. Now you can spray your plants or trees.

Store in a cool, dry place, shelf life is approximately three months from the day it’s made.

Note – use during mild weather, if you use it when the temperature is around 30 degrees Celsius or higher, it will damage your plants as the oil will clog the pores in the leaves. Morning or late evenings are a a good time. Also, don’t use it on plants that have hairy or soft leaves, as it will burn their leaves. Spray on both sides of the leaves, branches and bark to target pests wherever they may be hiding.

How Does White Oil Work?

White oil works by coating the insects in oil, blocking their breathing pores, which suffocates them. Because it works through physical suffocation, and not through a chemical action, insects cannot develop resistance to it, ever!

If you don’t have liquid soap, don’t despair, we use what’s available! If you have a bar of soap (natural of course – use castile soap bars which are made from olive oil preferably!), here’s the alternative recipe:

How to Make White Oil (with a bar of soap)

You will need:

  • 1/2 cup vegetable oil
  • 1 cup water
  • 1 tablespoon natural soap (in flakes) – grated from a bar of soap
  • 1 plastic spray bottle

Grate the natural soap, and put 1 tablespoon of these soap flakes into the spray bottle.

Pour the vegetable oil and water into the spray bottle.

Shake the spray bottle well. Now you can spray your plants or trees.

Slug and Snail Spray

You can make a simple spray very cheaply that dissolves slugs and snails without affecting your plants.

This spray simply consists of 1 part ammonia to 4 parts water in a spray bottle, with a dash of liquid soap to make it stick better on the pests. One or two squirts and they dissolve into a foaming green sludge. The slugs are gone instantly because they don’t have a shell to protect themselves, the snails might need a second squirt to coat them well in the spray. Set the nozzle of the spray bottle to a narrow jet so you can target them precisely and give them a good dose of the stuff.

You will need:

  • Plastic spray bottle
  • 1 teaspoon (5ml) of pure liquid soap (use pure organic castile soap, made from olive oil if you want to keep it all natural)
  • 100ml of Cloudy Ammonia
  • 400ml of water

I use a 500ml spray bottle with measurements on the side, which makes the process really easy. Pour 100ml of Cloudy Ammonia into the spray bottle, add 400ml of water, then add a dash of liquid soap to make the mixture stick better to pests. Shake bottle lightly, and you’re ready to hunt these nasty garden molluscs!

Best time to hunt these critters is just when it gets dark, or after it has just rained, which is when they crawl out for a feed. Grab a torch/flashlight, and look for them, if you see them, spray them. Do this over several nights and it puts a serious dent in their population.

Pyrethrum Daisy and Feverfew General Pesticide

This pesticide is natural Pyrethrum insecticide, which comes from the Pyrethrum Daisy (Tanacetum cinerariaefolium), a common companion plant in organic gardens, and Feverfew (Tanacetum parthenium), also of the daisy family, a herbal remedy for headaches, also with pest repellent/insecticidal properties. These flat composite flowers also attract beneficial predator insects such as hover flies which prey on aphids and other pest insects.

You will need:

  • 2 parts Feverfew flowers
  • 1 part Pyrethrum flowers
  • Mineral oil
  • 2 drops Sesame oil

To make this spray:

  1. Chop flowers.
  2. Cover with mineral oil.
  3. Soak overnight in a dark place.
  4. Strain liquid.
  5. Dilute one part liquid in six parts water.
  6. Add sesame oil and spray.

You can increase the effectiveness of the spray by adding additional ingredients to make it stick better to its intended target by using either a wetting agent or a spreader sticker, as described below.

Wetting Agent – Pure soap flakes used at 10g per litre of spray, or liquid soap at 10ml per litre of spray is an effective wetting agent for the above spray.

Spreader Sticker – Coconut oil used at 5ml per litre of spray is an effective spreading agent for the above spray.

Chilli and Wormwood Spray

This is a multi-purpose spray that can be used to:

  • Spray on plants to repel possums, rabbits, snails and slugs
  • Spray on plants to kill aphids, bean fly and white fly

You will need:

  • 1 cup of hot chillies, the hotter varieties work best
  • 1 cup of wormwood leaves
  • 6 cups of water

To make this spray:

  1. Blend chillies and wormwood with 1 cup of water.
  2. Add 5 cups of water and bring to the boil.
  3. Allow to stand for one hour.
  4. Strain and spray.

Caution: Do not allow to come in contact with eyes or skin!

You can increase the effectiveness of the spray by adding additional ingredients to make it stick better to its intended target by using either a wetting agent or a spreader sticker, as described below.

Wetting Agent – Pure soap flakes used at 10g per litre of spray, or liquid soap at 10ml per litre of spray is an effective wetting agent for the above spray.

Spreader Sticker – Coconut oil used at 5ml per litre of spray is an effective spreading agent for the above spray.

Coriander (Cilantro) Spray

This spray is effective against spider mites and aphids

You will need:

  • 1 part coriander plant
  • equal part water

To make this spray:

  1. Boil coriander and water for 10 minutes.
  2. Strain and spray.

You can increase the effectiveness of the spray by adding additional ingredients to make it stick better to its intended target by using either a wetting agent or a spreader sticker, as described below.

Wetting Agent – Pure soap flakes used at 10g per litre of spray, or liquid soap at 10ml per litre of spray is an effective wetting agent for the above spray.

Spreader Sticker – Coconut oil used at 5ml per litre of spray is an effective spreading agent for the above spray.

Pennyroyal Ant Repellent Oil

To use this ant repellent, simply paint Pennyroyal oil on ant tracks and nests.

You will need:

  • 1/2 cup of Pennyroyal leaves
  • 1 cup of Safflower oil

To make this oil:

  1. Combine Pennyroyal and oil in a blender.
  2. Bottle and cap.

Leave this mixture for a day in a warm spot, and then it is ready to use.

Chamomile, Chives, Elder, Horseradish and Casuarina General Fungicide

This fungicide is good for treating mildew, black spot, damping off and rust

You will need a selection of:

  • Chamomile flowers
  • Chive leaves
  • Elder leaves
  • Horseradish leaves
  • Casuarina leaves

To make this spray:

  1. Cover the leaves and flowers with water.
  2. Bring to the boil.
  3. Let stand 30 minutes.

Spray is now ready to use.

You can increase the effectiveness of the spray by adding additional ingredients to make it stick better to its intended target by using either a wetting agent or a spreader sticker, as described below.

Wetting Agent – Pure soap flakes used at 10g per litre of spray, or liquid soap at 10ml per litre of spray is an effective wetting agent for the above spray.

Spreader Sticker – Coconut oil used at 5ml per litre of spray is an effective spreading agent for the above spray.

Elder General Pesticide and Fungicide

This spray is especially good for aphids, caterpillars, thrips and black spot.

You will need:

  • 500g Elder leaves
  • 3.5L water

To make this spray:

  1. Simmer leaves in water for 30 minutes.
  2. Replace water lost as steam.
  3. Strain and spray.

You can increase the effectiveness of the spray by adding additional ingredients to make it stick better to its intended target by using either a wetting agent or a spreader sticker, as described below.

Wetting Agent – Pure soap flakes used at 10g per litre of spray, or liquid soap at 10ml per litre of spray is an effective wetting agent for the above spray.

Spreader Sticker – Coconut oil used at 5ml per litre of spray is an effective spreading agent for the above spray.

Borax Ant Bait

Ants can be a major pest in the garden because the “farm” aphids and scale – they safeguard them in their nests then carry them onto plants, and collect the honeydew that they excrete when the aphids and scale feed off the plant’s sap. The ants defend these pests from predators too. The simplest way to break the cycle is to bait the ants with a toxic bait that that doesn’t kill them instantly, they take it back to their nest, and feed the rest of the ants there, and it slowly destroys the whole colony. Borax is a natural occurring mineral salt, but is poisonous when swallowed, not recommended for use in homes with children and / or pets.

You will need:

  • 4 teaspoons of borax
  • 700ml of water
  • glass screw top jar
  • small jar
  • cotton wool

To make this bait:

  1. Mix 1 cup of sugar, 4 teaspoons of borax and 24 ounces (700ml) of water in a glass screw top jar.
  2. Shake thoroughly until you can see that all the crystals are dissolved.
  3. Now put 1 cup of this mixture into a smaller jar which you have filled halfway with loose cotton wool.
  4. Firmly screw the lid back on, seal around the band with weatherproof tape and using an awl punch a few small holes in the centre of the lid.
  5. Put this near the entrance of the nest or wherever they have made a path to your house.

The key is the ants will get into the jar to eat the sugar and return to the nest and pass it on to the rest of the colony. If you find many dead ants by the jar dilute the solution and try again. With a proper mixture the colony may be destroyed in a few weeks. It does take the destruction of the queen to completely eradicate a colony. Keep this away from kids and pets.

Earwig Bait Trap

This is a baited trap for earwigs that is buried in the soil with a small cover over it to prevent the trap filling water when it rains. It uses soy sauce as the attractant (bait) to draw the earwigs in, and the oils ensures that when they fall in, they can’t swim and crawl out, and they drown in the container.

You will need:

  • 2 tablespoons (30ml) soy sauce
  • vegetable oil
  • any small container that is reasonably deep, such as a small jar, plastic yogurt container, tuna tin or similar
  • cover for the small container, which is reasonably larger than the container, such as a lid from a larger jar (large plastic lids work well)

Bait for Earwigs can be made as follows:

  1. In a small container (small yogurt container, small jar, tuna tin, large pill bottle or anything that is fairly deep), add 2 tablespoons (30ml) of soy sauce, and then pour in vegetable oil to form a layer about 6mm deep.
  2. Another way to do it is to put water in the fill the container up to 1/3 of its depth, add the soy sauce, then add just enough oil to cover the surface in a thin layer.
  3. Now bury the container up to its top in the soil, but leave it stick up a slight amount so the soil and surrounding dirt doesn’t fall in and fill the trap, which will render it ineffective. Put some kind of cover or lid over the trap, so it doesn’t get flooded and washed out when it rains. Use a cover larger than the container, so it extends a reasonable way around the edge of the small container to act as a kind of shelter. You can prop up the lid with 4 stones around the jar so that it leaves a small gap all the way around between the container and the cover for the earwigs to crawl under.
  4. Leave it there for a few days and it will fill with earwigs. You can dump the resultant mess into the compost, and then refill the container for the next round.

This selection of homebrew pest control measures should get your garden out of trouble and deal with most problems you’ll come against. Best of all, they’re fairly natural, cheap and easy to make!

Happy brewing!!!

Winter Washing of Fruit Trees

Although it may look like there is not much happening with your fruit trees over winter, the microscopic world of fungi is making plans, strategically laying in wait in the cracks and crevices of your trees until the weather warms up. The most prevalent fungus is Peach Leaf Curl, causing the disfigurement of leaves, and sometimes the fruit, on your peach, nectarine, apricots and even almonds. However there are many other fungal problems that may occur and winter spraying is a good way to help reduce the incidence of fungal problems.

Peach Leaf Curl will cause the lovely new growth on your trees to appear blistered and puckered and in severe cases it can cause pimples on fruit and premature fruit drop. In the cool moist weather of early spring the fungus will multiply and if the cycle is not broken your trees will continue to be infested year after year.

Other fungal diseases that may be dormant on stone fruit include Shot Hole, Freckle Spot, Rust and Powdery Mildew.

There are several things you can do to minimise the spread of Peach Leaf Curl and other fungal diseases in the garden.

Practise good garden hygiene. Pick up fallen leaves from the ground and avoid putting them in your compost. Remove damaged or rotten fruit and keep the tree pruned to an open vase shape to increase air circulation.

Plant your tree into well prepared soil in the right position with plenty of sun and good air circulation. Keep up a regular fertilising and watering schedule.

Spray your trees during winter with a low impact fungicide. ‘Winter-washing’ helps to kill off any spores and can greatly reduce the incidence of Peach Leaf Curl and other fungal problems.

Winter Washing

The best spray to use is either copper oxychloride or lime sulphur sprayed in alternate years. The first spray should be in late autumn at leaf fall just before the tree enters its dormancy. Spray again at bud swell or bud burst in late winter or early spring. Once the leaves have opened out it is too late to spray for Peach Leaf Curl and many other fungal diseases. Safe and effective spraying can only be done at the end of the following summer.

When spraying fruit trees, be aware of the potential impact that ‘spray drift’ may have on surrounding vegetation, soil micro-organisms, pets and humans. Spraying is usually done to the point of ‘run-off’, where the spray liquid has completely covered the tree surface and runs off on to the ground. It may be prudent to lay spray sheets down so non-targeted areas are being protected.

Only make up enough spray for the job at hand to avoid the problem of having to dispose of excessive amounts of unused spray.

Spraying may not be 100% effective so be vigilant over summer and remove any leaves showing signs of fungal disease as soon as they appear.

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