What Are Black Cherry Aphids – A Guide To Managing Black Cherry Aphids

What are black cherry aphids? As you might suspect, black cherry aphids are a problem of cherry growers across nearly every region of the United States. While the pests will feed on any type of cherry, sweet cherries are most susceptible.

Fortunately, managing black cherry aphids is possible, and damage is usually minimal if the pests are properly controlled in early spring. However, damage is sometimes severe on young trees, where even a few of the pests can create havoc. Read on for more black cherry aphid information and tips on black cherry aphid treatment.

Signs of Black Cherry Aphids

Black cherry aphids are easy to spot. They are shiny, metallic black, and at 1/8 inch (.3 cm.), are quite a bit larger than most aphids. The pests emerge from eggs that overwintered in the bark, hatching as soon as buds begin to open in spring. Mature black cherry aphids may be winged or wingless.

Large colonies of black cherry aphids develop quickly, with two or three generations appearing by mid-summer. By this time, the pests generally move on to alternate food supplies – especially weeds and plants of the mustard family. The aphids return to the trees in autumn to mate and lay eggs.

Signs of black cherry aphids include curled, distorted leaves and a large amount of sticky “honeydew” on cherries and leaves. The honeydew often attracts black sooty mold, which can render the fruit inedible.

Managing Black Cherry Aphids

The most effective way to control black cherry aphids is to protect and encourage the presence of natural predators such as lady beetles, syrphid flies, lacewing larvae, parasitic wasps and soldier beetles.

If possible, avoid broad-spectrum insecticides, which are harmful to beneficial insects, including bees. Products such as Malathion or Diazinon should be used only as a last resort in black cherry aphid treatment.

Watch trees closely when buds are appearing in late winter. Yellow sticky cards placed on various parts of the tree will quickly give you a clue about the severity of a black cherry aphid infestation. Aphids are easier to manage before the leaves are curled, and you may be able to dislodge the pests with a strong stream of water.

For stubborn infestations, early spring is also the best time to spray black cherry aphids with horticultural oil, a natural substance that will kill the aphids as they hatch. You can also spray affected trees with insecticidal soap, but don’t spray when temperatures are very warm, or when bees are present. Evening is the safest time to apply insecticidal soap sprays. You may need to reapply the soap two or three times to gain control.

Need help with what to do in your garden?

Q What are aphids?

A Small insects, including greenfly and blackfly, which are found in clusters on the leaves and shoots of many plants.

Caption: Distorted shoots and clusters of small insects are characteristic of aphid attack

Q How do I recognise aphids?

A The insects are green, brown or black. They are egg-shaped, about 2mm long, usually without wings and are often grouped in large numbers. Even at a distance you’ll notice shiny honeydew deposits, distorted or rolled-up leaves, or distorted shoots.

Q What damage do aphids cause?

A Aphids feed by sucking sap from the plant, distorting its growth. This may mean that new shoots are stunted, leaves cannot photosynthesise very effectively, or fruit is disfigured and fails to mature properly.

Aphids also excrete shiny, sticky honeydew as a waste product which can cover leaves, encouraging the growth of black sooty mould. This is unsightly and may further damage a plant’s health by blocking out the light it needs. Aphids are also responsible for spreading viruses.

Q How can I control aphids?

A In the majority of cases, it’s best to do nothing. Trees tolerate some damage, and the aphids’ natural predators will help get rid of them.

If the infestation is heavy, you can squash them with your finger and thumb or spray with Bayer Natria Bug Control or Westland Resolva which are approved for use on fruit.

Q What about natural predators of aphids?

A Insectivorous birds such as tits can consume huge numbers of aphids and aphid eggs. Feed birds in winter and put up nest boxes to encourage them. Ladybirds and lacewings are also big aphid-eaters. Entice them into your garden by allowing some aphids to survive and avoid using insecticides that can harm them.

Q Which aphids attack cherry trees?

A The main pest is cherry blackfly (Myzus cerasi).

Q How do I recognise cherry blackfly?

A Colonies of small, black insects infest young leaves and shoots and can smother an entire tree, causing distorted leaves and the death of shoot tips.

Sooty mould growing on the honeydew adds to the disfigurement. Large trees can tolerate such attacks, but the shape and future cropping of small trees can be affected.

Q When does cherry blackfly appear?

A The blackfly hatch in April and feed on the undersides of leaves. By the time you see the distorted leaves, much of the damage has been done, so check from early April and take action if needed. Stop any spraying in July, when the aphids migrate to bedstraws and other wild plants for the summer, and allow natural predators to finish off those remaining on the trees. In the autumn, mature aphids return to the fruit trees and lay their eggs on the bark.

Q Which aphids attack plum trees?

A Three species of aphid affect plums and damsons:

Damson-hop aphids (Phorodon humuli) are yellow-green and shiny, and occur on young shoots. They cause only slight distortion of the leaves. They hatch in April, migrating to hops from early summer, where they become a troublesome pest. In autumn they return to the trees to lay eggs.

Plum leaf-curling aphids (Brachycaudus helichrysi) occur in large colonies on young shoots, causing severe leaf-curling. They hatch in December and January, attacking the leaves in bud. Yellow-green in colour, they spend summer on border perennials.

Mealy plum aphids (Hyalopterus pruni) are bluish-green with a waxy coating and live in tightly packed masses on the undersides of leaves. They hatch in April and can build up to damaging levels by June. They do not distort the leaves, so this aphid is usually first detected when the foliage and fruit become sticky with honeydew and black sooty mould develops.

These aphids spend the summer on reeds and waterside grasses, though they may stay on the fruit trees as late as August. They return to the fruit trees in autumn to lay eggs.

Q How do I control aphids on plums?

A Check shoots in early spring (no later than March) and take action if large colonies of early-hatching aphids are visible. If sooty mould occurs later in the season, you may need to spray the undersides of leaves against mealy plum aphids.

Cherry-Black cherry aphid

Myzus cerasi

Pest description and crop damage The adult aphid is black, globular in shape and about 1/8 inch long. Black cherry aphid is the only black aphid on cherry. These aphids curl foliage, reduce terminal growth, and deposit honeydew on cherries which can be difficult to remove prior to commercial packing. Damage to young trees can be significant.

Biology and life history These aphids overwinter as eggs in crevices and twigs. The eggs hatch near budbreak, and the nymphs feed on unopened buds and the undersides of leaves. Nymphs inject a toxin into leaves, causing them to curl and protect the aphids as they feed. After two to three generations, winged forms are produced that migrate to summer hosts, which include weeds, ornamental plants, and vegetables, or plants of the mustard family. After several more generations, the winged forms migrate back in the fall to the fruit tree to mate and lay the overwintering eggs.

Pest monitoring Begin observing shoots before budbreak, as management is best undertaken early while the aphids are small and prior to leaf curl.

Management-biological control

Aphids have many natural enemies, which include lady beetles, syrphid fly larvae, and green lacewings. Avoid broad-spectrum insecticide applications that would disrupt these controls.

Management-cultural control

Home orchardists: Wash aphids from plants with a strong stream of water or by hand-wiping. Aphids are difficult to control once leaves begin to curl as insects are protected within the curled leaf from direct contact by water and chemicals. Aphid populations tend to be higher in plants that are fertilized liberally with nitrogen. Avoid excessive watering which, together with nitrogen applications, produces flushes of succulent growth.

Management-chemical control: HOME USE

Warning: These pesticides are hazardous to bees. Look for bee precautionary statements on product labels and do not use these products during bloom or if bees are foraging in the orchard.

  • carbaryl
  • esfenvalerate
  • gamma-cyhalothrin
  • lambda-cyhalothrin.
  • malathion
  • pyrethrins-Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

Warning: These materials are hazardous to bees. Do not use during bloom or if bees are foraging in the orchard.

Dormant-season and delayed-dormant sprays

  • chlorpyrifos (Lorsban 75 WG) at 2.0 to 2.67 lb/a or Lorsban 4E at 4 pints/a. REI 4 days. May be mixed with horticultural mineral oil (rates vary; see product label). Do not exceed one application of chlorpyrifos as a dormant or delayed-dormant per season. Avoid contact with foliage in sweet cherries as premature leaf drop may result. Extremely toxic to fish and aquatic invertebrates; avoid spray drift and runoff to surface waters.
  • diazinon (Diazinon AG500) at 4 pints/a + horticultural mineral oil (rates vary; see product label) or Diazinon 50WP at 4 lb/a. Do not exceed 6 gal of oil when applying Diazinon 50WP. REI 4 days. Do not exceed one dormant application of diazinon per season.
  • dimethoate (Dimethoate 400 EC) at 1 quart/a. REI 10 days (REI is 14 days in areas where average annual rainfall is less than 25 inches). Do not exceed one pre-harvest application per season. Can cause leaf burning and fruit marking. Do not use on cherries to be exported to Japan.

Spring and summer sprays

  • acetamiprid (Assail 70WP) at 2.3 oz/a. REI 12 hr. PHI 7 days.
  • diazinon (Diazinon 50W) at 4 lb/a. REI 4 days. PHI 21 days. Do not exceed one in-season foliar application per year.
  • esfenvalerate (Asana XL) at 4.8 to 14.5 fl oz/a. REI 12 hr. PHI 14 days. Asana may aggravate spider mite problems. Extremely toxic to fish and aquatic invertebrates; avoid spray drift and runoff to surface waters.
  • imidacloprid (Provado 1.6F) at 4 to 8 fl oz/a. REI 12 hr. PHI 0 days. Do not use until pollination is complete and bees are no longer present in canopy or ground cover.
  • malathion (Malathion 57EC) at 1.5 pints/a. REI 12 hr. PHI 3 days. Malathion may be used in the evening after bee activity. Do not apply within 300 ft of aquatic habitat.
  • spirotetramat (Movento) at 6 to 9 fl oz. REI 24 hr. PHI 7 days. Do not apply until after petal fall.
  • thiamethoxam (Actara 25WDG) at 3 to 4 oz/a. REI 12 hr. PHI 14 days. Actara is extremely toxic to bees exposed to direct treatment or residues.

Pest & Disease Control for Cherry Trees

As it grows, a cherry tree may experience issues caused by pests or diseases. Factors such as location, weather, and upkeep play a part in which issues your cherry tree encounters and how well it stands up against them. Disease-resistant cherry trees are easy-care options for growers who prefer a low-spray or no-spray orchard, and – for all cherry trees – routine maintenance* can help keep most problems at bay.

*Examples of good practices are: adequate watering, fertilizing only as needed, seasonal pruning, preventative and active spraying, fall cleanup and winter protection.

The following are merely intended as a means of identifying potential issues. Don’t be alarmed – a cherry tree may experience a few of these in its lifetime, but certainly not all at once.

NOTE: This is part 7 in a series of 11 articles. For a complete background on how to grow cherry trees, we recommend starting from the beginning.

Cherry Tree Pests

Aphids

Tiny, pinhead-sized insects, varying in color depending on the type. Will cluster on stems and under leaves, sucking plant juices.

Symptoms: Leaves curl, thicken, yellow, and die. Aphids produce large amounts of a sticky residue called “honeydew” that attracts insects like ants. Honeydew also becomes a growth medium for sooty mold.

Control: Spray

  • GardenTech® Sevin® Concentrate Bug Killer
  • Bonide® Fruit Tree Spray

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Insecticidal Soap
  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Neem Oil
  • Monterey Fruit Tree Spray Plus
  • Monterey Horticultural Oil

Cherry Fruit Fly

Adults are similar in appearance to a housefly, but smaller. Larvae are yellowish-white grubs. Traps are an option for luring adults.

Symptoms: Small, pinpoint-sting marks visible on fruit surface. Eggs are laid under fruit skin. Hatched larvae tunnel, making railroad-like mining pattern.

Control: Spray

  • Bonide® Fruit Tree Spray

Control: Natural Spray

  • Bonide® Captain Jack’s™ Deadbug Brew Garden Dust
  • Bonide® Citrus, Fruit & Nut Orchard Spray

Moths

Includes: Orange Tortrix, Oriental Fruit Moth, Codling Moth, Winter Moth, Western Tussock Moth, Cherry Scallop Shell Moth, etc.

Adults are moths that vary in size and appearance. Larvae are pinkish-white with a red-brown head, about ½-inch long. Pheromone traps are an option for luring moths.

Symptoms: Damage first appears on vegetative growth, and left untreated will eventually infest fruit. Larvae tunnel in through the stem and often exit near the pit.

Control: Spray

  • Bonide® Fruit Tree Spray
  • GardenTech® Sevin® Bug Killer

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Captain Jack’s™ Deadbug Brew Garden Dust
  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Thuricide® BT

Borers

Includes: American plum borer, Pacific flatheaded borer, Peach twig borer, Peachtree borer, Shot hole borer

Adults are small brown beetles that may target the graft location (in young cherry trees) for laying eggs as well as damaged or sunken areas. Grubs have horseshoe-shaped heads and cream-colored bodies. Difficult to control once infested. Preventative spraying (including the ground around the roots) is a strong defense. Traps – in the form of tanglefoot-coated logs or posts that are later removed from the site and burned – are an option for luring adults.

Symptoms: A thick, gummy substance (sap) leaking from round holes on the trunk or in a crotch of the tree. Grubs tunnel through trunks, weakening and eventually killing the tree. Eggs hatch and larvae tunnel into tree’s vascular tissue.

Control: Manual

  • If infested, use a fine wire to try to pierce, mash, or dig grubs out.
  • Traps (tanglefoot-coated logs or posts) can lure adults. Remove from site and burn after trapping.
  • Preventive spraying (including the ground around the roots)

Control: Spray

  • GardenTech® Sevin® Concentrate Bug Killer

Additional Resources

  • Contact local county Cooperative Extension for further advice

Japanese Beetle

Adult is a metallic-green beetle, which skeletonizes leaves. Larvae are cream-colored grubs that feed on turf roots prior to maturity. Turf pest-control may help reduce grub populations; check turf product labels for timing and control of grubs. Traps are an option for luring adult beetles.

Symptoms: Adults are often seen in groups – large infestations can cause stunted growth and stress by skeletonizing a majority of the leaves.

Control: Manual

  • If infestation is minimal, knock Japanese beetles into a jar of soapy water solution (they will become immobile when frightened as a defense mechanism)

Control: Spray

  • Bonide® Fruit Tree Spray
  • GardenTech® Sevin® Bug Killer

Control: Natural Spray

  • Bonide® Captain Jack’s™ Deadbug Brew Garden Dust

Leafhopper

Small, active, slender-winged insect appearing in various colors. Usually found on undersides of leaves.

Symptoms: Slows new growth; leaves become whitened, stippled, or mottled. Leaf tips may wither and die. Prone to carrying diseases to and from plants and trees; damaged caused by leafhoppers may be greater than the feeding done directly by the insect.

Control: Manual
Hand-removal of webbed foliage and keeping area free of weeds and debris may be enough to manage the pest.

Control: Spray

  • Bonide® Fruit Tree Spray
  • GardenTech® Sevin® Concentrate Bug Killer

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Insecticidal Soap
  • Monterey Fruit Tree Spray Plus
  • Monterey Horticultural Oil

Mites

Pinpoint-sized arthropods, appearing in many different colors depending on the type. Often found on undersides of leaves.

Symptoms: Sap feeding causes a bronze appearance in leaves. Severe infestations exhibit some silken webbing. Droughts or dry spells are advantageous for mite infestations.

Control: Spray

  • Bonide® Fruit Tree Spray
  • GardenTech® Sevin® Bug Killer

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Insecticidal Soap
  • Bonide® Neem Oil
  • Monterey Fruit Tree Spray Plus
  • Monterey Horticultural Oil

Scale

Usually on bark of young twigs and branches, encrusted with small (1/16-inch) hard, circular, scaly raised bumps with yellow centers. May also be on fruit.

Symptoms: Sap feeding weakens the tree.

Control: Spray

  • Bonide® Fruit Tree Spray
  • GardenTech® Sevin® Bug Killer

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Insecticidal Soap
  • Bonide® Neem Oil
  • Monterey Fruit Tree Spray Plus
  • Monterey Horticultural Oil

Tarnished Plant Bug

Yellowish-brown, winged insect that may have black spots or red stripes.

Symptoms: Damage is caused by injecting toxins into buds and shoots, causing stunted vegetative growth and sunken areas (or “cat facing”) on fruit.

Control: Spray

  • GardenTech® Sevin® Concentrate Bug Killer
  • Bonide® Fruit Tree Spray

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Insecticidal Soap
  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Neem Oil

Tent Caterpillar

Adults are moths. Caterpillars are a hairy, grayish brown with cream-colored spots or stripes down the back.

Symptoms: Encases large areas in webbing and feeds on enclosed leaves.

Control: Manual

  • Remove webs with a rake (caterpillars are removed with webs) and burn.

Control: Spray

  • Bonide® Fruit Tree Spray

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Insecticidal Soap
  • Bonide® Thuricide® BT
  • Monterey Fruit Tree Spray Plus

Thrips

Tiny, slender, fringed-wing insects ranging from 1/25-inch to 1/8-inch long. Nymphs are pale yellow and highly active. Adults are usually black or yellow-brown, but may have red, black, or white markings.

Symptoms: Feeding occurs on vegetation by puncturing and sucking up the contents, causing appearance to be deformed or discolored (similar to damage by mites and lace bugs).

Control: Spray

  • GardenTech® Sevin® Bug Killer

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Captain Jack’s™ Deadbug Brew Garden Dust
  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Insecticidal Soap
  • Monterey Fruit Tree Spray Plus
  • Monterey Horticultural Oil

Cherry Tree Diseases

Armillaria Root Rot

Also “oak root fungus”, “shoestring rot”, and “mushroom rot”

All stone-fruit rootstocks are susceptible to Armillaria root rot, which smells distinctly like mushrooms and occurs on the upper roots and/or crown of the tree. This destructive fungus lives within dead and living roots is transferred from root system to root system. It can live for up to 30 years.

Symptoms: Roots infected with Armillaria mellea have whitish-yellow fan-shaped mats between the bark and the wood. The tree trunk is girdled. Dull, yellowed, or wilted foliage is usually the first sign of trouble; infected trees usually die slowly.

Control: Manual
Exposing an infected crown and upper root area of a cherry tree may help to slow its growth into the crown. In spring, remove soil from around the base of the tree to a depth of 9 to 12 inches. Leave the trunk exposed for the remainder of the growing season. During the spring, summer, and fall, keep the upper roots and crown area as dry as possible. Recheck the hole every few years to make sure it has not filled in with leaves, soil, and other matter; the hole must be kept open and the crown and upper roots exposed.

Botrytis Rot

Damage commonly occurs to stone fruit and their blossoms during a wet, cool season. It appears on ripening fruit as brown spots and becomes covered with light brown spores.

Symptoms: Appears similar to brown rot (below). Fungus will overwinter in the soil and in plant debris.

Control: Spray

  • Bonide® Captan Fruit & Ornamental
  • Bonide® Fruit Tree Spray
  • Bonide® Fung-onil™ Multi-Purpose Fungicide

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Neem Oil
  • Serenade® Garden Disease Control
  • Monterey Fruit Tree Spray Plus
  • Monterey Horticultural Oil

Brown Rot

Includes: mummy rot and twig and blossom blight

Brown rot is a fungal disease that commonly affects stone-fruit trees, including cherry trees, especially after a long, warm, wet spring. It is one of the most common cherry-tree diseases. It affects the fruit tree’s flowers and fruit crop, but is not fatal. Fortunately, brown rot is easy to spot, prevent, and treat.

Symptoms: Blossoms turn brown and wither, but stay on the tree. Small sunken spots may appear at the base of infected blossoms, in the twig itself. Gummy brown “sap” may seep from these sunken areas. Leaves at the twig ends appear shriveled. Furry gray or beige mold forms on affected blossoms or twigs. The fungus rapidly spreads to the fruit.

Control: Manual
Plant a resistant variety, like Stark® Gold™ Sweet Cherry in a well-drained location. Prune regularly to keep trees open to light and air circulation, and remove any pruning debris, damaged or diseased fruit and limbs, as well as fallen fruit to avoid sites for fungi to thrive (do not compost). Thin fruit to avoid good fruit touching infected fruit. Disinfect your pruners between cuts to avoid spreading the fungi.

Control: Spray

  • Bonide® Captan Fruit & Ornamental
  • Bonide® Fruit Tree Spray
  • Bonide® Fung-onil™ Multi-Purpose Fungicide

Control: Natural Spray

  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Copper Fungicide

Spray preventatively if brown rot is problematic in your area, even before symptoms appear.

Buckskin (X-disease)

Buckskin disease is spread by some leafhopper species and is managed by planting disease-free stock, controlling weeds that host leafhoppers and removing leafhopper vectors and all diseased trees.

Symptoms: Diseased trees produce leathery, bumpy fruit that is pale in color, even at harvest-time. On Mahaleb rootstocks, trees rarely have fruit issues, but will suddenly droop above the graft union. Buckskin disease (also called “X-disease”) is caused by a phytoplasma organism in the cells of infected trees. Trees are usually infected in summer and fall, but will not show symptoms until the following year.

Control: Manual
Prune off infected twigs and limbs where cankers have affected the branch.

Cut out cankers that are less than half the branch circumference. Use a small, sharp knife and score the wood all the way around the canker, about an inch away from it. Dig the tip of the knife into the wood and bark as you work, and maintain a 1-inch margin around the circumference of the canker.

Slip the knife under the bark and remove the diseased inner bark, which is usually a rusty brown color. Round the edges of each incision to promote rapid healing, but do not remove the wood from the uninfected area below the canker.

Clean up any wood chips or debris and either burn it or dispose of it in the trash. Do not compost infected debris. Bleach the knife used to excise the canker, rinse and pat dry.

Apply fungicide spray to small wounds during wet periods and during dormant periods.

Canker (bacterial and cytospora)

Cytospora canker is caused by the fungus Cytospora spp. and attacks trees via weak or injured bark. Bacterial canker is caused by Pseudomonas syringae. Both tend to occur during cool, wet weather. They act and are treated similarly.

Symptoms: Infection appears as yellow-orange and black regions that later ooze a gummy substance which may have a foul odor. Cankers eventually develop in the branches, encompassing the circumference of the wood until it dies.

Control: Manual

Prune off infected twigs and limbs where cankers have affected the branch.

Cut out cankers that are less than half the branch circumference. Use a small, sharp knife and score the wood all the way around the canker, about an inch away from it. Dig the tip of the knife into the wood and bark as you work, and maintain a 1-inch margin around the circumference of the canker.

Slip the knife under the bark and remove the diseased inner bark, which is usually a rusty brown color. Round the edges of each incision to promote rapid healing, but do not remove the wood from the uninfected area below the canker.

Clean up any wood chips or debris and either burn it or dispose of it in the trash. Do not compost infected debris. Bleach the knife used to excise the canker, rinse and pat dry.

Apply fungicide spray to small wounds during wet periods and during dormant periods.

Control: Spray

  • Bonide® Fung-onil™ Multi-Purpose Fungicide

Control: Natural Spray

  • Bonide® Copper Fungicide
  • Bonide® Thuricide® BT
  • Monterey Horticultural Oil

Crown Gall

Caused by Agrobacterium tumefaciens — a bacterium that inhabits the soil and causes rapid, abnormal growth (developing into galls). Can spread through injury to roots in the soil as well as through gardening tools carrying the bacterium.

Symptoms: Trees appear stunted and slow growing; leaves may be reduced in size. In mature, fruit-bearing aged trees, may see little or no fruit. Woody, tumor-like growths called galls appear, especially at the crown (ground level) and below. Growths can restrict water and nutrient flow, but often the damage isn’t extensive enough to cause immediate or total death. If tree has died, inspect roots for hard, woody ‘tumors’ to identify Crown Gall as the cause. Note: Crown Gall is not the only thing that can cause stunted trees.

Control: Prevention

  • Purchase gall-free nursery stock. Crown gall symptoms are generally well developed on finished nursery stock, making inspection a useful prevention strategy.

Additional Resources

  • Contact local county Cooperative Extension agent for further advice

Phytophthora Root Rot and Crown Rot

Soil pathogens in the genus Phytophthora can cause crown and root rot diseases of almost all fruit and nut trees, as well as most ornamental trees and shrubs. This disease appears if the soil around the base of the tree remains wet for prolonged periods, or when the tree is planted too deeply.

Symptoms: Infected trees often wilt and die quick as soon as the weather warms up. Leaves may turn dull green, yellow, or even red or purplish. Symptoms may develop first on one branch then spread to the rest of the tree. Dark areas appear in the bark around the crown and upper roots. Gummy sap may ooze from the diseased trunk. Reddish-brown areas may show between the bark and wood.

Control: Manual
Good water management/drainage is the key to prevention. Never cover the graft union with soil and try to avoid direct watering of the crown. If you suspect crown rot, carefully cut away affected bark at the soil line. Trees can sometimes be saved by removing soil from the base of the tree down to the upper roots and allowing the crown tissue to dry out.

Control: Spray

  • Bonide® Fung-onil™ Multi-Purpose Fungicide

Powdery Mildew

Caused by Podosphaera leucotricha — a fungus that overwinters in buds and emerges during humid, warm weather progressively throughout the growing season.

Symptoms: Whitish-gray powdery mold or felt-like patches on buds, young leaves, and twigs. Leaves may crinkle and curl upward. New shoots are stunted.

Control: Spray

  • Bonide® Fung-onil™ Multi-Purpose Fungicide

Control: Natural Spray

  • Bonide® All Seasons® Horticultural & Dormant Spray Oil
  • Bonide® Citrus, Fruit & Nut Orchard Spray
  • Bonide® Copper Fungicide Spray or Dust
  • Bonide® Neem Oil
  • Serenade® Garden Disease Control
  • Monterey Fruit Tree Spray Plus
  • Monterey Horticultural Oil

Other Cherry Tree Issues

No Blossoms or Fruit

Sweet cherry trees take about 4 to 7 years after planting (on average) before they bloom or bear fruit. Pie/Sour/Tart cherry trees bear a little sooner, within 3 to 5 years after planting. If enough time has been allowed to pass, and the cherry tree is otherwise healthy, there are a few things to do to help it become fruitful.

  • Make sure a pollinator variety is present. Most cherry trees require another different variety of cherry tree to be fruitful. Note: Sweet cherry trees and Pie/Sour/Tart cherry trees are not reliable pollinator for one another.
  • Make sure your cherry tree variety is recommended for your zone. Low winter temperatures can injure sensitive fruit buds and blossoms, hindering fruit production.
  • Space trees far enough apart to help avoid nutrient or light competition. Adequate space encourages a healthy and productive tree. Spacing can be estimated by the mature spread of the tree.
  • Prune to help keep the fruiting wood and vegetative wood in balance so that there isn’t too much leaf development in lieu of blossom development in mature trees — or too much fruit-bud development and not enough leaves to “feed” the fruit.
  • Know your soil. Soil conditions, and the presence of necessary nutrients, help keep a cherry tree’s roots supplying nutrients through its vascular system. If the soil is poor, or poorly drained, this affects the health and viability of the tree as a whole. If the tree is being over-fertilized, especially with a fertilizer high in nitrogen, it may develop lush, vegetative growth (leaves and branches) instead of developing fruit buds or blooming.

Additional Resources:

  • Solving Fruit Tree Blooming & Bearing Problems

Sunscald and Sunburn (Scorching)

Sunscald/sunburn occurs during hot, dry growing seasons — with or without humidity in the air, but most commonly when humidity is low. Sunscald is also called winter injury or “southwest injury” as it commonly affects the southwest side of tree trunks during winter. Brown, crispy edges appear on leaves. Warm, clear days cause bark to expand and nights that are several degrees cooler will cause the bark to contract, damaging cells and causing splits and cracks in the trunk.

  • Protect trunks prior to winter with tree guards or a diluted solution of water and white latex paint (50/50).
  • Water new trees every 7 to 10 days during the growing season (if there is no rain within the week), or as needed (as the soil becomes dry to the touch).
  • During the growing season, consider constructing a temporary shade cloth to protect trees from the sun on hot, dry days. Water as needed (see above).

Additional Resources:

  • Winter Protection for Fruit Trees
  • Drought Issues & How to Protect Your Trees

Water Stress

Can be caused by both overwatering and underwatering. Overwatering commonly presents as pale green to yellow leaves and leaf drop, which can weaken a tree, lead to root rot, and ultimately kill the tree. Underwatering often presents as discolored (usually yellowed), dry leaves. Tree may appear to wilt overall. Prolonged lack of water can kill the tree.

  • Water new trees every 7 to 10 days during the growing season (if there is no rain within the week) or as needed (as the soil becomes dry to the touch).
  • If planted in a location where the soil does not adequately drain water after heavy rains (leading to standing water), relocate the tree as soon as possible.
  • If drought-like conditions persist, consider slow-trickle drip irrigation to allow water to reach the roots rather than wash over soil surface.

Additional Resources:

  • Plan Ahead for Rainy Weather

Wind Injury

Symptoms: Can involve injury such as leaning/uprooted trees, breaks, tears, or wind-burned foliage. Depending on the severity of the injury, a cherry tree can either bounce back from minor damage or succumb to the wind-caused harm. This is determined on an individual basis and the health of the tree before the damage occurred.

Control: Manual

  • Adequately tamp soil around the tree’s roots (and thoroughly water) at planting time to remove air pockets and ensure good contact with the soil. Air pockets and loose soil around the roots can cause the tree to rock easily, leaving it vulnerable to leaning or uprooting.
  • Use tree stakes for new trees, dwarf trees, and trees planted in high-wind areas to help support upright growth and avoid leaning, uprooting, and breaking.
  • Selectively thin fruit that may be weighing down limbs to reduce stress from the weight, and avoid tears or breaks during gusty weather. Be aware: pests and disease may also take advantage of resulting broken or torn areas if damage occurs.

If tender new foliage is blown or whipped around by the wind, it may appear discolored (dark — like a burn or bruise). Damaged leaves can be removed to encourage healthy, new growth.

In This Series

  • Introduction

Getting Started

  • Acclimate
  • Location
  • Planting
  • Soil Preparation

Care & Maintenance

  • Fertilizing
  • Pest & Disease Control
  • Pruning
  • Spraying
  • Watering

Other Topics

  • Harvesting

PESTS AND DISEASES OF CHERRY TREES

Article by David Marks

Cherry trees are well known for suffering from a range of pests and diseases in the UK. Treatment has been made much easier in recent years with the introduction of dwarfing and semi-dwarfing rootstocks.

Bird damage can now be much more easily controlled because the trees can be kept to a manageable size. The same applies to diseases such as canker – affected branches are within reach and can be quickly treated.

SILVER LEAF OF CHERRY TREE

The following are symptoms of a Silver Leaf fungal infection:

  • A silver sheen to the leaves. This typically does not affect the whole tree, it affects only branches which are suffering from the disease.
  • Cut through a suspect branch which is 3cm or more wide and you will see a brown stain in the centre. wet the cut if this is not immediately visible. This is the defining symptom of Silver Leaf in cherry trees.
  • Affected branches will die back.

An example of the silver sheen to the leaves is shown below:

The confirming sign of Silver Leaf infection is shown below, where a branch has been sawn through to reveal the tell tale brown stain:

For more identifying features of Silver Leaf and how best to treat it, visit our page dedicated to this disease of cherry trees.

BROWN LEAVES – CHERRY LEAF SCORCH / SPOT

When most of the leaves on your cherry tree turn brown before autumn, your tree almost certainly has a fungal infection. The two most common are cherry leaf scorch and cherry leaf spot.

The symptoms differ slightly but the treatment remains the same. Click here for our page devoted to fungal problem.

BIRDS AND CHERRY TREES

Birds can be a real problem with cherry trees and pigeons are the main culprit. There are many suggestions on the internet and in gardening books for deterring them but, take our word for it, only one works. You need to net the fruit tree, or at least individual branches, if birds are a problem in your area.

Both fruit and younger leaves can be affected. We first describe fruit damage then briefly describe leaf damage.

In extreme cases you may not even notice the birds, the only sign of a problem being no fruit or damaged leaves. The birds eat the under-ripe so quickly that some gardeners don’t realise that birds are doing the damage. Look for signs of cherry stones in the surrounding area. Birds drop the stones after they have eaten the cherry flesh.

Pigeons and other birds have an annoying habit of pecking at the fruit just before it’s ripe and it’s no use trying to beat them to it. Under-ripe cherries will not ripen when picked from the tree.

Pigeons and other birds can be a major problem

If your tree is on a dwarfing or semi-dwarfing rootstock such as Gisela 5 or Colt then this will not be too much of a problem. However, if you have a full sized cherry tree (which can easily be higher than a two-storey house) then you have a different problem altogether. Our advice, in that case, would be to buy a new cherry tree on an appropriate rootstock.

Not only do we recommend netting as the only solution, but so do all the professional growers. Decoys, hanging CDs, silver foil and other solutions just don’t frighten pigeons for long enough.

Leaf damage to a cherry tree

Leaf damage (see above picture) which primarily affects younger tender leaves is almost always caused by birds, and pigeons are the prime culprit. The damaged leaves will have jagged edges where the birds have torn away the leaf flesh with their beaks. Very frequently, you will never see the birds which have caused the damage.

A cherry tree can be productive for many decades so it makes economical sense to buy netting which can reliably prevent birds and which will last for many years.

Your own personal experience will dictate when the best time is to cover with netting. We would suggest that initially you try early June if they are eating the fruit. If you find that the birds attack the developing fruit before that then note the time that the damage first starts for a guide the next year. With leaf damage the netting needs to applied by mid April.

LEAF MINERS

The visible symptoms are squiggly lines which appear on the upper side of the leaves. The lines can be a variety of colours, white or deep brown being the most common (see the picture below). The pest which is causing the damage on cherry trees is Lyonetia clerkella often called the Apple Leaf Mining Moth. They normally have three generations per year.

Picture courtesy of Jenny L

There are no pesticides available to UK gardeners for the Apple Leaf Mining moth. However, although unsightly, they will not affect the health of an established cherry tree.

There are two steps you can take to reduce the damage. The first is to pick off and burn badly affected leaves. The second is to pick up all fallen leaves and burn them as well. The pupae overwinter in the bark of the tree or on the ground. Clearing the surrounding soil (and gently hoeing it) of any debris will also help.

BACTERIAL CANKER

The following are symptoms of Bacterial Canker on cherry trees:

  • Branches and stems have sunken and malformed areas on them. The size of the affected area can be as small as a two penny coin but can also spread over very large areas of the branches.
  • Damaged areas will often have a dark gum oozing from them which may harden to become almost solid after time.
  • Leaves turn prematurely yellow but do not shrivel. They drop off sooner than normal.
  • There may be small brown marks on the leaves which fall out leaving the leaves with small holes in them, this often referred to as shot hole.

Young cherry trees are more likely to be affected compared to established trees. There are no chemicals or treatments available to the amateur gardener (Bordeaux mixture and similar copper based treatments are no longer sold in the UK) for Bacterial Canker.

Your only option is early detection and removal of infected wood. Click here for our page dedicated to the identification and treatment of Bacterial Canker.

SPLITTING OF CHERRIES

One of the commonest problems with cherry trees is the fruit splitting. This is not a pest or disease, it is a condition that some cherry trees suffer from. Variable weather can affect the likelihood of this happening.

Picture courtesy of Yara

Different varieties of cherries are more or less likely to fruit splitting. For instance, Sweetheart, Sunburst, Summer Sun, Penny and Morello are relatively resistant to fruit splitting and cracking whereas Skeena and Napoleon are likely to have a good proportion of the fruit split.

Aside from choosing a resistant variety there is very little that you can do to prevent fruit splitting. Excessive nitrogen contributes to thin cherry skins so avoid this type of fertiliser. Some gardeners believe that overwatering causes splitting but in fact the evidence does not support this.

Cherry fruits absorb the majority of their liquid from the fruits surface so it is humid conditions and water on the skin surface which can contribute to skin splitting rather than excessive water at the roots (see this article here). If you can protect your cherries from the worst of the rain then that will help greatly but it’s very difficult to do.

SMALL BLACK LEECHES / SLUGS ON LEAVES

This is the Cherry Slug Sawfly (Caliroa cerasi) sometimes also called the Pear Slug Sawfly. It affects pear, cherry and apple trees as well as some ornamental shrubs, hawthorns in particular. On fruit trees, the black leech like creatures are in fact green but covered with black slime. The slime is a protection mechanism to avoid being eaten by birds.

Picture courtesy of reader Anthony T
Cherry Slug Sawfly (click to enlarge)

The lifecycle of the Cherry Slug Sawfly starts with the pupae overwintering in the soil beneath the tree. In spring the actual sawflies emerge and lay eggs on the leaves. The eggs then hatch into the leech like creatures.

It is this slug / leech like stage which does the damage. They feed on the upper surfaces of the leaves with their black slime making them very unattractive to birds. The picture above shows the leaf damage very clearly, it is almost always restricted to the top surface of the leaf.

The larvae feed for three to four weeks and then fall off onto the ground. They will then hatch into a second generation within the same year and it is this second generation which does the significant damage. This normally occurs in late August to mid September.

In severe cases they can damage a huge amount of leaves. They are rarely fatal to the tree and fruit production is normally unaffected because the damage occurs so late in the year. They do make the leaves very unsightly however and can cause problems for already weak trees.

Removing them by hand and disposing of them is one solution but the size of many fruit trees makes this a difficult task. They can be knocked off with a strong jet of water. Spraying with a contact insecticide such as Bifenthrin was the most common treatment but in the UK this insecticide is no longer permitted for amateur gardeners.

Scotts Bug Clear is the recommended alternative but there is little hard evidence for how effective it is with the Cherry Slug Sawfly.

LEAVES CURLING

This normally a sign of aphids such as blackfly and greenfly. The most common is the Cherry Blackfly. They attack the leaves causing them to curl upwards and inwards which protects the aphids from predators such as birds. They are attracted to young shoots in particular which may end up as a distorted mass.

Often gardeners cannot see the aphids with the naked eye and it is necessary to use a magnifying glass. Another sign of aphids is the presence of ants on the leaves or stems of the tree. They farm the aphids and only make matters worse. The earlier you treat aphids the better your chances are of a good crop of cherries.

Adult cherry Blackfly

We have a page dedicated to identifying and treating (organic and chemical methods) aphids which can be found here.

CHERRY FRUITS DROP BEFORE RIPENING

If the tree is otherwise healthy, fruits dropping off has two main causes. Where 30% or less fruit drop this is quite natural. Cherry trees often over-produce fruit and they have a natural mechanism which causes some of the fruit to fall off before ripening. This allows the tree to concentrate its energies into producing a slightly smaller amount of healthy fruit.

Where more than 30% of the fruits fall off before ripening this is sometimes called “cherry tree run off”. The exact causes are not known but it is believed to be adverse weather conditions earlier in the season, frequently at blossom time. Currently there is no cure for this. The overall health of the tree is not affected and it should resume normal fruit production in later years.

Research is ongoing to find out more about Cherry Fruit Drop an the article found here may be of use. It would suggest that where the problem occurs over several years a solution might be to reduce the number of fruits (as early as possible) to about 2 per fruiting spur. Normally there are six to eight fruits per spur.

BLACK CHERRY APHIDS

The first signs of Black Cherry Aphids will be in spring when leaf buds begin to open. The aphids have a black, shiny surface to them and are about a quarter of a centimetre long. They are clearly visible to the naked eye and will multiply rapidly.

They cause the leaves to curl in on themselves making treatment very difficult. In many cases a cherry tree will not be badly affected as far as cropping is concerned although younger trees may be damaged. The aphids will suddenly disappear in July, looking for more suitable food, however the distorted leaves will remain.

They should be treated exactly as described for aphids here.

SPOTTED WING DROSOPHILA

The key identifier for Spotted Wing Drosophila is one or more pin prick sized holes in the skin. Later on the fruit will collapse in on itself.

Picture courtesy CDFA

This is a difficult pest to control so we have written a page specifically about how to identify it and treatments. .

The leaves on my cherry tree have small holes in them and are turning yellow. What is the problem?

Cherry leaf spot is probably responsible for the symptoms on your cherry tree. Cherry leaf spot is caused by the fungus Blumeriella jaapii. The fungus produces small purple spots on the upper surface of the leaves. Eventually the spots turn reddish brown. After several weeks, the centers of the spots may drop out, producing a “shot-hole” appearance. Affected leaves often turn yellow and drop prematurely.

Cherry leaf spot occurs on both sour and sweet cherries in Iowa. Mild wet weather in spring creates a favorable environment for cherry leaf spot.

The cherry leaf spot fungus survives the winter on dead leaves on the ground. Spores that are released from these leaves during rainy periods in spring may infect newly emerging leaves. Raking and removing fallen leaves helps to break the disease cycle. The risk of infection can also be reduced by improving air circulation within the tree canopy with some light pruning. The application of fungicides, beginning at petal fall, is another way to control cherry leaf spot.

Bugs on My Cherry Tree

I have a new weeping cherry and it looks bad. I have water dripping all the time. I discovered red/brown lady like bugs without the black dots that fly and are eating the leaves on new tree. Bug-b-gone didn’t seem to make them fly away.

Advertisement

Hardiness Zone: 6a

Stewart from Voorhees, NJ

Stewart,

It sounds like you have a severe infestation of aphids. Aphids are tiny soft-bodied insects that come in a variety of colors. Some species have wings, other do not. They are sucking insects that feed on the sap of young leaves. As they feed they excrete a sticky, sugary substance called honeydew. The “water” dripping all of the time on your cherry tree is the honeydew being produced by the feeding aphids. Although aphids will usually not seriously harm healthy established trees, heavy infestations can result in leaves turning yellow and wilting from excessive sap removal. Aphids are also vectors for several harmful plant viruses. Worse than the aphids themselves are the large amounts of honeydew they secrete. Not only does this make a sticky mess on the ground beneath your trees, but honeydew is a magnet for attracting a fungus called sooty mold. The mold accumulates on leaves and branches, causing them to turn black and inhibiting photosynthesis.

Advertisement

The ladybug beetles on your cherry tree are actually your friends in this situation (incidentally, not all ladybug beetles have spots), so don’t try to get rid of them. The more ladybug beetles you see the better. They are aphid-eating machines! Adult ladybugs eat aphids whole-as many as 1,000 in one day. Ladybug nymphs also eat aphids when they are in their larvae stage-stabbing them with their mandibles (biting jaws) and sucking out their juices (similar to how aphids suck sap from leaves). Since your tree is young and probably not very tall, try spraying the leaves with a strong jet of water from your garden hose every few days. This will help blast aphids off the leaves. The combination of water and ladybugs should work to solve your problem. If heavy infestations continue to persist, you may want to try applying a summer oil or an insecticidal soap formulated for fruit trees.

Advertisement

Ellen

Cherry Insects & Diseases

Diseases:

Black Knot

Black knot of plums and cherries is a widespread and serious disease throughout North America. The black knot fungus mainly affects twigs, branches, and fruit spurs. Although sometimes trunks may also become diseased. Usually, infections begin on the youngest growth. On infected plant parts, abnormal growth of bark and wood tissues produce small, light-brown swellings that eventually rupture as they enlarge. Smaller twigs usually die within a year after being infected. Larger branches may live for several years before being girdled and killed by the fungus. The entire tree may gradually weaken and die if the severity of the disease increases and no effective control measures are taken. Fungicides can offer significant protection against black knot, but are unlikely to be effective if pruning and sanitation are ignored.

For more information about Black Knot, .

Silver Leaf

(Chondrostereum purpureum)
Silver Leaf is a fungal disease and its name refers to the silver luster of leaves that occurs on some hosts. However, not all trees show silver foliage when infected, but rather the first sign of the disease is twig and branch die-back. Leaves that are affected may later start to show brown areas in the middle and at the edges. Toxins produced by the fungus affect leaves, and on some hosts it may kill branches or entire trees. Diagnosis can be confirmed by cutting through a branch that is at least 2.5cm (1in) in diameter, wetting the cut surface and checking it for a brown stain in the wood. To control the disease, prune at the first sign of silvering. Make the cut below the diseased area into healthy wood. Cover pruning wounds that are larger than 1.5cm with pruning sealer. Remove and bury or burn all infected branches, leaves and twigs. This will help to reduce the amount of disease the following year. No chemical control is available.

Powdery Mildew

This fungal disease attacks leaves and twigs. Symptoms include white patches on new leaves, severely affected leaves may start to curl and drop prematurely. Rake remove and destroy any fallen leaves. High humidity and intermittent rains make ideal conditions for the fungus. This disease can be managed by spraying with a fungicide. Proper tree pruning can reduce the chance of infection of Powdery Mildew by creating an unfavourable environment for the fungus.

Cherry Leaf Spot

(Blumeriella jaapii)
The fungus that causes this disease usually attacks the leaves but may affect twigs and stems. Leaf Spot occurs in many parts of North America and the world where humid conditions occur. Symptoms include small dark coloured spots on the leaves and the leaves may begin to yellow while areas around the spots may remain green. Some leaves may drop prematurely. During wet weather white patches may appear on the undersides of leaves at the centre of the dark spots. These white patches contain fungal spores. The disease overwinters when infected leaves fall to the ground. Wind and rain splash the spores up onto the tree’s new leaves and buds in the spring. To manage Leaf Spot, it is recommended to spray with a fungicide. Rake and destroy any fallen leaves to help reduce the amount of disease the following year.

Brown Rot

The fungus that causes this disease, can infect fruit, blossoms and small branches. Symptoms include blight, cankers and fruit rot. Cherry fruits that are affected rot very quickly, they shrivel and become covered in a brownish-gray substance. Powdery tufts of brown gray spores are visible on the outside of infected flower shucks, and on infected fruit or twig surfaces especially under wet weather conditions. The dried infected fruits are called mummies as a result of their appearance. Wind and rain spread the spores from infected mummies and twigs to uninfected parts of the tree. Mummified fruit and cankers should be pruned during the dormant season and either burned or buried deeply in the soil. Remove and destroy all dropped and rotted fruit from the ground beneath the tree. Blossom blight is much more serious on sweet cherry than on sour cherry. Sweet cherries (not sour) are also very susceptible to infection the first few weeks after fruit set, and a petal fall spray is recommended if the weather is warm and wet. Superior brown rot fungicides should be used on sweet cherries three weeks before the fruits are ripe.

Bacterial Canker

Canker is caused by two related bacteria. The symptoms on the leaves are similar to those of leaf spot but the two diseases are distinguished by the cankers on trunks, limbs and branches that exude gum during late spring and summer in the case of Bacterial Canker. Spots on the leaves are dark brown, circular to angular, and sometimes surrounded with yellow. Leaves that are on the terminal side of cankers may wilt and die. Lesions on green cherry fruit are brown with an area of wet tissue, as well black depressions may be left on the skin of the fruit. Outbreaks are common following cool wet weather after bloom. Prune out diseased branches in late winter or early spring. The bacteria can be transmitted by pruning tools so these should be disinfected between trees if bacterial canker is present. Spray with a fungicide that contains basic copper sulfate in the fall. However, copper sprays can cause injury to stone fruit.

Insects:

Black Cherry Aphids

This problem is reported wherever cherry trees are grown. Black Cherry Aphids are the only type of aphids that affect cherry trees. The aphids are small soft-bodied insects about 3mm in length and may or may not have wings. Affected leaves become stunted, twisted and curled. The Honeydew secreted by the aphids drips on the leaves, fruits and surrounding ground. Ants may be present. A black fungus begins to grow on the honeydew where it has fallen. Treatment includes spraying with an insecticide to kill the aphids.

Borers

Small holes may appear in the trunk from which a gummy sap oozes. During the growing season some of the leaves and branches may wilt and die, turning brown. Since borers usually attack weakened or stressed trees, it is important to maintain their health with enough water and proper fertilizer. There are two types of borers that affect cherry trees; the Shothole Borer and the Peachtree Borer. The tunnels created by the borers interfere with the flow of water and nutrients within the tree. Keep the tree healthy by watering regularly and applying a fertilizer. The trunk and large branches can be sprayed with an insecticide designed to kill borers, however they can be very difficult to control. Contact a professional arborist.

San Jose Scales

Symptoms may include leaves that are pale green or yellow and drop or they may turn brown and stay on the tree into the winter months. The fruit may be covered with specks. Small, hard, gray raised bumps encrust the bark. If left uncontrolled large branches may be killed after two or three seasons. To treat, spray the trunk and branches with horticultural oil during the dormant season in early spring.

Additional insects to be aware of include Cherry Fruit Flies, Pearslugs, Tent Caterpillars and the Oriental Fruit Moth. Treat these problems with an insecticide and for caterpillars also use a bug band.
Learn more about pest control products offered through TreeHelp.com.

Leave a Reply

Your email address will not be published. Required fields are marked *