- Planting Lupine Flowers – How To Grow Lupines
- How to Grow Lupines
- Getting More Lupine Flowers
- Plant of the Week – Lupins
- Ongoing Care of Lupins
- How to grow lupins
- Growing Lupin
- Further references
- Germination and seedling development in lupins
- The seed
- Lupins Care Guide
- Ideal Soil for Lupins
- Climate Tolerated by Lupins
- Planting Position for Lupins
- Uses for Lupins
- Learn About Lupine
Planting Lupine Flowers – How To Grow Lupines
Lupines (Lupinus spp.) are attractive and spiky, reaching 1 to 4 feet (30-120 cm.) in height and adding color and texture to the back of a flower bed. Lupine flowers may be annual and last only for a season, or perennial, returning for a few years in the same spot in which they were planted. The lupine plant grows from a long taproot and does not like to be moved.
Lupines grow wild in some areas of the United States, where they are hosts for the larvae of endangered species of butterflies. Wildflowers of the lupine plant generally come in in hues of blues and white, although domesticated lupines offer flowers in blues, yellows, pinks and purples. Tall, spiky racemes produce lupine flowers similar to those of the sweet pea plant.
How to Grow Lupines
Growing lupines is as simple as planting seeds or cuttings into a sunny area with well-drained soil. If planting lupine from seed, scratch the seed surface or soak seeds overnight in lukewarm water to allow the seed coat to be easily penetrated. Seeds of the lupine plant may also be chilled for a week in the refrigerator prior to planting.
This may also be accomplished by planting lupine seeds in the fall and letting Mother Nature do the chilling through the winter. Direct sowing of lupine seeds in autumn is perhaps the easiest method. Lupines produce seed which will re-produce more flowers the following year if not removed from the growing lupine.
Average soil is best for growing lupines. Utilize this trait and plant lupines in areas of the landscape that have not been composted or amended in other ways.
Getting More Lupine Flowers
To encourage blooms, fertilize lupines with a plant food that is high in phosphorus. Nitrogen rich fertilizer may encourage growth of the foliage and do little to promote flowering. Deadhead spent blooms for returning lupine flowers.
The lupine plant fixes nitrogen in the soil and is a great addition to your vegetable garden or any area where nitrogen loving plants will be grown. A member of the pea family, lupines are beneficial in many ways.
Now that you know how to grow lupines, add this tall, showy bloom to an area where lupine flowers will be visible and act as background for other full-sun blooms. A flowering ground cover planted beneath the lupine plant helps keep roots cool and will benefit from the nitrogen in the soil, creating a showy display in the landscape.
Plant of the Week – Lupins
Ongoing Care of Lupins
Lupins will live for at least five years or more and can continue for up to 10 years, dependant on the the conditions they are grown in. Here’s a little advice to help you keep these beautiful plants looking great each year.
Lupins are very strong growing perennial plants and are quite capable of looking after themselves as far as water and nutrients are concerned. They have long tap roots which allows the roots to find water in most conditions. Manual watering may well result in the crowns rotting and therefore it is not advised unless in severe drought.
The roots of Lupins can also find their own nutrients as they have nodes on them which produce their own nitrogen. Don’t feed lupins after their initial feed at planting time, nitrogen based fertilisers will encourage lush green growth which make them more prone to aphid attack.
Removing / Deadheading Flowers
To get the longest flowering period from your lupins, cut off the flower heads when they have died down each season. The flowers will die from the base of the flower head upwards. The time to dead head Lupins is when two thirds of the flower has died. New, smaller flowers will soon appear extending the flowering season.
Winter Care for
As winter begins the foliage starts to turn brown and die down and there is no need to do anything. The foliage will slowly die back and does no damage. In early spring when new shoots appear, clear away any remaining dead foliage to allow good ventilation at ground level.
How to grow lupins
Lupins are a cottage-garden favourite offering height and colour to the middle of a border in May and June. Their flowers are borne on impressive spires and have a pea flower style. Their foliage is soft green and coated in fine silver hairs.
Watch our video guide to growing lupins.
These hardy plants are ideal for cutting and although not scented they make a real statement in the home and garden. Numerous garden hybrids are available, so the colour choice is huge. Bees love them.
Follow our lupin Grow Guide, below.
Lupins enjoy full sun or dappled shade. The ideal soil is moist but well-drained and can be acid, chalky or neutral. Like many other perennials with tall flowers, they will benefit from a sheltered position.
The back or middle of a border is ideal. Avoid planting them in containers as they are far more successful in the garden. If you plant lupins in containers the growth is often weak, leaving it open to attack from aphids.
Video: Caring for lupins – Golden Rules featuring expert lupin grower, Debbie Copeman
Although a very traditional plant, lupins can be planted to create a modern look. Plant in large drifts running through ornamental grasses for an unusual effect.
Dig a planting hole in a well-drained soil. Plant and firm in place. Water and provide a plant support if planting in summer. Young plants tend to establish better in the garden than larger, more mature specimens.
Sowing lupin seeds
Lupins do not come true to type from seed, so seed packets are likely to be a mix of colours. Lupins can be divided in spring (not autumn) but division can be tricky as plants have a strong central tap root. The easiest way to propagate plants is by basal cuttings taken in spring. Watch our video guide to taking basal cuttings from a range of plants. Lupins will self-seed in the garden so lifting the seedling with a garden trowel and potting them in is also a great way of generating new plants.
Before propagating lupins and other plants, check that they are not protected by plant breeders’ rights.
Lupinus ‘Persian Slipper’
Lupins: problem solving
The new spring shoots of lupins are tempting to slugs and snails so be vigilant and protect them, otherwise they will be munched. However, the main enemy of the lupin is the lupin aphid (Macrosiphum albifrons). They are grey aphids that are spotted on plants anytime between April and September. To control cut off very badly infested flower spikes and spray with a chemical control. Aphids can be rubbed off by hand or with a blast of water, but this is a labour of love.
Caring for lupins
Deadhead lupins once flowers have faded and you will be rewarded with another flush of flowers. Lupins are not regarded as long-lived plants. Expect to replace plants after about six years. In autumn, cut plants right back to the ground after collecting seed.
Use lupins as a green manure
Lupins can be grown as a green manure to improve tired soils. Growing the ‘green manure’ lupin will boost nitrogen levels. Sow seed direct in April and dig in to the soil in September.
Great lupins to grow:
- Lupinus ‘Cashmere Cream’ – reaches 90cm. Creamy white flowers in June
- Lupinus ‘Rachel de Thame’ – a stunning white and pink lupin with June blooms. Reaching about 90cm
- Lupinus arboreus (pictured) – a beautiful evergreen shrub. Height 2m
- Lupinus ‘The Pages’ – dark maroon spires of flowers in May and June reaching an impressive 1.2m
- Lupinus ‘Russell Hybrids Mixed’ – a real favourite offering a wonderful range of mixed colours. Enjoy yellow, blue, red and pink flowers in May and June. Height 90cm
- Lupinus ‘Terracotta’ – warm orange/red flowers in May to July. Reaches a height of 1m
See the Victorian Winter Crop Summary for an up to date guide to lupin varieties and last season’s yield results.
There are two types of Lupin; the narrow leaf species (Lupinus angustifolius) and the larger seeded and broader leaf Lupinus albus. The latter is generally produced for human consumption, whilst the higher protein narrow leaf lupin is better placed as stock feed.
For healthy high yielding crops it is important to have seed tested for seed borne diseases. If seed is coming from WA or SA it must be tested for Lupin anthracnose, a disease caused by fungal infection (resulting in deformed growth) which only occurs in these two states of Australia.
Even though many of the newer varieties of lupin have better disease resistance (see table below), it is still a good idea to have seed tested for cucumber mosaic virus (CMV) and Anthracnose.
If a paddock has a history of lupin disease it may be best to rest or sow a different crop, allowing the disease to die back. With good quality seed and favourable conditions, lupin is a productive rotational crop option.
Mice infestations can be a big issue for farmers, with both the sowing and flowering stages targeted as a food source.
Lupins don’t tolerate free lime (up to 4 per cent) and will grow poorly on hard setting or shallow (< 25cm) soils. The narrow-leaf varieties are suited to acid (as low as pH 4) sandy to sand over clay soils and well structured loam soils.
Direct drilling seed is a best practice, with hard setting heavier soils sown shallower and looser sandy soils deeper, optimum sowing depths are between 10 cm and 30 cm.
When sowing lupin crops try to achieve between 45 – 60 plants per m2 or, 75 – 100 kg a hectare. It is important to remember that albus is a larger seed and therefore will need to be sown at a higher rate (160 kg a hectare). The narrow leaf variety is well suited to acid sandy soils with the angustoflius preferring the wider range from sandy to well-structured loams.
Seeding rate (kg/ha) = Plant density (plants/m2) x 100 seed weight (g) x 10 ÷ Germination percentage
See the Victorian Winter Crop Summary for the latest lupin time of sowing guide.
Lupins prefer moderate temperatures and rainfall, they are not tolerant of frost and large losses of flowers can occur if frost is serve enough or ongoing. They like moderate temperatures, too many days over 30o C will also see flowers drop.
Manganese, phosphorous and nitrogen (& minor elements zinc and sulphur) will assist crops to reach their potential. As all soils vary, it is important to conduct pre-sowing soil tests to work out application rates. Manganese deficiencies can result in split seed disorder, this can be prevented by applying manganese to the soil (direct drill with seed) or via foliar spray when pods on the main stem are 2 to 3 cm long and the secondary stems have nearly finished flowering.
Red-legged earthmite (Halotydeus destructor) is a black-bodied mite with red legs; it damages seedlings as they emerge.
Lucerne flea (Sminthurus viridis) is a small (2.5 mm), wingless, light green hopping insect. It chews through leaves in layers resulting in “window-pane” like holes.
Native budworm (Helicoverpa punctigera). The caterpillar damages maturing seed in pods during the flowering and podding stage of plant growth.
Brown leaf spot (Pleiochaeta setosa) has small web like spots on leaves and pods. Infected leaves drop off, lesions may girdle stems
Pleiochaeta root rot (Pleiochaeta setosa) Browning and rotting of tap and lateral roots, seeding plant death.
Cucumber Mosaic Virus causes bunching and stunted growth; they have few pods and remain green while other plants are browning off
See the Victorian Winter Crop Summary for the latest Lupin disease resistance table.
Harvesting should occur when moisture levels are 14 per cent and the crop is mature (pods brown, seed yellow). If putting stock onto the stubble it is recommended to do so shortly after harvest (to avoid stem rot and fungus from rains).
Harvest is where high pod loss can occur, so speak to your agronomist about header settings for your particular variety (open front or conventional headers can be used).
Lupin roots can grow down to 2.5 metres, the rhizobium is required for nodulation and nitrogen fixation. Once nodulation occurs in acid soils, inoculation will not be required for the next five years.
CMV and anthracnose are tested as the amount of pathogen DNA in a standard sample size. Testing can be facilitated by commercial grain testing businesses.
Sampling seed is best done soon after harvest by taking samples as the seed streams from the header to the holding bin or when it is transferred to the silo. A small bucket or bag can be passed through the stream at several different times during transfer, then mixed together and sub-sampled to the laboratories required weight.
See the Victorian Winter Crop Summary for an up to date guide to lupin varieties.
- Victorian Winter Crop Summary for the latest varieties and yields.
- SARDI Lupin Variety Sowing Guide
- DPI, SARDI (2000) Lupins in South Australia and Victoria.
- Department of Agriculture and Food (WA) Lupin Essentials series.
Germination and seedling development in lupins
The lupin seed consists of a seed coat (also called testa) and embryo. The embryo is already a well developed plant consisting of two cotyledons, five or six leaf primordia on a tiny seedling axis and the radicle (embryonic root) (Figure 2.2). Cotyledons account for about 75% of the weight of the seed. The seed coat accounts for almost 25% of the weight. If too dry, lupin seeds can be brittle and vulnerable to damage during harvesting, handling and sowing. Cracks can occur in the embryo that may reduce seedling establishment and vigour.
The point of attachment of the cotyledons to the seedling axis is particularly susceptible to damage. Loss of a cotyledon will reduce seedling vigour because cotyledons are the food store for the growing seedling. Cracks elsewhere in the seed embryo can lead to seedling abnormalities such as a missing taproot or upside down growth.
Germination and seedling emergence
After sowing into moist ground, lupin seeds imbibe water readily. The water content increases from about 10% for dry seed to about 60% at germination. During this time, the embryo swells and the radicle ruptures the seed coat and pushes through it. When the radicle is 5mm long, the seed is considered to have germinated.
After germination, the radicle continues to grow downwards and firmly anchors the plant in the soil, while the remainder of the seedling pushes upwards through the soil. The radicle becomes the plant’s taproot. The seedling stem between the radicle and cotyledons is called the hypocotyl. The hypocotyl forms a downward hook to protect the growing apex of the seedling and cotyledons as they are pushed upwards towards the soil surface. A seedling is considered to have emerged when any part of it protrudes above the soil surface. When soil is moist and the temperature averages 15°C, emergence occurs about six to seven days after sowing seeds 4cm deep.
Lupin emergence is called hypogeal emergence because the hypocotyl expands to push the cotyledons and growing apex above the soil surface. This differs from the epigeal emergence of faba bean and field pea in which the cotyledons remain where the seed was placed in the soil and only the stem above them (epicotyl) lengthens to protrude from the soil. The size of lupin cotyledons and the force needed to push them towards the surface makes lupin comparatively sensitive to soil crusting compared with species that have epigeal emergence.
After germination, the hypocotyl hook straightens and the cotyledons turn green and expand further as the shoot apex continues to develop (Figure 2.3). The hypocotyl above the soil surface also turns green. Depth of sowing can be determined on seedlings by measuring the length of the white portion of hypocotyl above the root junction. Because the cotyledons and shoot apex are above the soil, lupin is particularly susceptible to sandblasting, grazing and insect damage, compared to cereals, in which the shoot apex remains underground during vegetative growth. See Dracup and Kirby (1996) for more detailed information.
Lupins Care Guide
Ideal Soil for Lupins
The latin name for lupin, Lupinus, is derived from lupus meaning wolf or destroyer. Because lupins will grow in poor soil they have also attracted the misleading idea that they can destroy the fertility of the soil. This is not true; lupins make their own nitrogen enabling them to grow in poorer soils but not chalk. Ideally a well drained, neutral to slightly acidic soil will ensure 100% success but most soils will be fine.
Climate Tolerated by Lupins
Pretty much any climate will be tolerated by lupins. They are very hardy herbaceous perennials, withstanding frost to at least -25C. In very wet conditions, lupins may succumb to crown rot but if well established, will survive most conditions.
Planting Position for Lupins
Just like us lupins love the sun and their flower spikes will follow its movement east to west on a bright day. However, we have lupins growing on a north facing site which thrive just as happily. Full sun is said to improve the colour of the flower spikes too.
Uses for Lupins
Because lupins flower primarily in the month of flaming June they coincide with a popular time for couples tying the knot. If you want to be original take some beautiful lupin florets as confetti, strip the blooms just before you set off. As a statement plant in the border, few plants can match the tall, colourful lupin spire. They make excellent pot plants too which is not an idea usually associated with this genus. Put one or two on your patio and enjoy a heavenly morning and evening scent reminiscent of peppery moss.
More Lupin Tips Care and Tip Guides
- Buy quality hardy lupins and/or quality seed.
- Sowing Seed – sow from February to September either in a seed tray or if only a few seed, sow altogether in a deep pot. This can be done in a cold greenhouse, coldframe or window sill. When your lupin seedling has at least 4 true leaves, pot on into a 3″/9cm to grow on. When rooted, plant your lupin firmly where it is to flower, be it in a pot (yes, you can grow lupins in pots) or in a garden and water it in. Lupins do not come true so yours will be a lovely rainbow mix of colours.
- Plugs. Your plugs needs to be potted firmly into a 3″/9cm pot and grown on till the roots show at the bottom. Water sparingly and from the base if possible. A general purpose peat based compost is ideal.
- Planting out 3″/9cm pots- make sure you plant firmly and water in just once. Don’t keep watering – let the plant’s roots find water and so establish properly.
- Feeding – Use bonemeal in the autumn and calcified seaweed. A high potash feed of tomato feed or Vitax will give good flower colour if in pots. Do not use farmyard manure, even well rotted, as it will rot the crowns. Lupins do not need feeding once in the ground as they have nitrogen fixing nodules on their roots which capture all the nitrogen they require from the air.
Earlier in the year, World Vision asked me if I would like to follow the progress of their garden for RHS Chelsea 2012, from the initial design right through to its implementation for the show. My personal circumstances made that impossible, but I have been keeping up with the project and have been watching with interest a development that is right up our street.
In a change to the original design, John Warland and Sim Flemons of FlemonsWarlandDesign have added an unusual edible to the planting – tarwi, Lupinus mutabilis. Tarwi is a stunning edimental, which produces edible beans. I have seen it growing twice in the UK – once at Oxford botanic garden, and once at the Eden Project.
Through World Vision, I have been able to interview Susann Laughton, the horticulturalist at Plantify rising to the challenge of growing these barely-known plants in time for Chelsea:
How many lupin plants are you growing? And how many are expected to be included in the garden?
The designers have ordered 100 plants for The World Vision Garden. As the quality requirement for RHS Chelsea plants is very high, only half of them might make it through the first-round of John and Sim’s selection process. There will be about 20 square metres of planting in the garden and, if possible, there will be one or two Andean lupins per square metre.
How did you sow the seeds?
We had to try various germination methods as there is little information about this lupin anywhere. After soaking the dried beans in water we initially tried the traditional method of germinating them in cotton wool, which was very successful. We also experimented planting them directly into soil at various depths exposing them to various moisture levels. We tested the influence of temperature on their germination rate by using propagators which didn’t seem to make any difference. They certainly like it moist, but not too wet conditions which cause them to rot.
The method of placing the seeds between a moist layer of cotton wool was the most satisfying as you could can see the first results of little shoots emerging from the seed within 48 hours. This method has a 70-80% germination rate. That makes this an ideal plant to be grown with children. You get an instant gratification and see changes happening every day.
How easy were they to find?
Returning from Bolivia, FlemonsWarlandDesign asked Plantify.co.uk to source the rare lupins for The World Vision Garden at RHS Chelsea this year. Despite best effort, the search was initially in vain since there are no official growers of the Andean Lupin in the UK. It is even unknown to the official holders of the National Lupin Collection.
For weeks research and investigations continued until – upon receiving a tip off – we managed to narrow our search to the South American community in London. Here, to our surprise, we found the seeds being sold wholesale – but as Tarwi beans, for food – through an international distributor, who is importing them directly from Peru.
Have you grown these plants before?
No – and, as far as we’re aware, neither have any other professional growers in the UK. So, Plantify is growing the edible Andean Lupin exclusively for The World Vision Garden at RHS Chelsea this year.
Do they need any special care?
They like moisture, but nothing too wet. Over-watering causes them to rot very easily. They love a lot of sunshine and grow very fast in good conditions. We started growing them in our front room to make sure they were well nurtured in their earliest days, but they’re now growing happily in a poly tunnel – the Andean Lupin normally flowers in June, but we are hoping to bring them into flower in time for Chelsea, as a unique feature of The World Vision Garden.
Many thanks to Susann for taking time out from nurturing these babies to answer my questions, and to World Vision for the photos. I also have also blogged an interview with one of the designers, who explains why tarwi has been added to the planting plan.
If you enjoyed this blog post then you’ll love my new book, Jade Pearls & Alien Eyeballs, which is all about incredible edible plants and the people that grow them.
Lupinus polyphyllus is the most popular of these stately plants. They can grow up to 5 feet high and, as far as I am concerned, should be a permanent fixture in all gardens.
Lupines come in both annual and perennial varieties. Lupines do not like hot weather and do best in the Northeast and Canada. They also grow well in the Pacific Northwestern U.S. and some parts of California. They also grow abundantly throughout Europe as far north as Norway. In some countries, like New Zealand, they are considered a noxious weed, taking over vast areas and forcing out native plants. There are species of lupine to be found on nearly every continent. They are not usually happy in the hot, humid South.
Due to their ability to enrich the soil with nitrogen, they can be planted in the poorest of soil and thrive. Therefore, they do not require to be fertilized, although, if planted in fertile soil with lots of good organic matter present, they will produce the best display of large flower spikes. They can withstand full sun or the lightest shade. I have them planted in both areas. Those in full sun put on a much better display, the ones I have in shade can still hold their own, the only difference being, the shaded plants are shorter, with equally short, yet still showy spikes of flowers. Still beautiful in either case. They do love their water, so bear this in mind if you are in an area with watering restrictions. Some of the newer hybrids will tolerate short periods of drought.
For the best effect, Lupines should be planted in large groups. Their spectacular flower spikes can reach anywhere from 12 to 60 inches in height, making them a good focal point in any perennial bed. Blooming in June and July, their flowers have a noticeable honey scent and are attractive to many butterflies, as well as humming birds and bees. They come in many colours, pink, red, purple, white, violet, apricot, blue and even yellow. They have attractive blue-green, almost tropical looking leaves. Deadheading spent flower spikes will prolong the blooming time and they will bloom again, though not as spectacularly, in late summer. The spikes are great as a cut flower, alone or in an arrangement.
If you want to grow your own, they are easily grown from seed. Lupine seed pods, when ripe, explode. When they turn yellow and rattle inside, place them in a paper bag and let them explode, then gather them up. Simply soak the seeds overnight and press into soil. Lupines do not like to be transplanted, so if you have to start them in pots, be sure to move them to the garden when they are 3 to 6 inches high. Be sure to plant them where you want them, the adult plants, due to their deep tap root, transplant miserably. I have had some success, though, moving them first thing in the spring, when they are just beginning to show, a few inches high. They must be watered in well. The best way to grow from seeds, in my opinion, is to scatter them in the garden in the fall.
Some Lupines have a high alkaloid content, making them poisonous to both humans and animals. Keep this in mind if you have critters or children that tend to taste your garden. This fact should also make them deer and rabbit resistant. I have never had them eaten by deer, but the odd nibble has been taken by rabbits. Lupines can be susceptible to powdery mildew, so good air circulation is needed. In my zone, I have never had a mildew problem on my Lupines(knock on wood), but my gardens are in a very open area. Crown rot can occur if kept too wet, so a well draining soil is helpful. Aphids can be a problem. I have had Lupines growing in my perennial beds for 15 years. This past summer was the first time I have had an aphid problem. They were horribly infected, after blooming, almost overnight. I solved the problem by cutting them right to the ground and removing any dead foliage in the area. They grew back stronger than ever.
This wonderful, old fashioned plant is a mainstay in my gardens. I look forward to them every year. Scattered in large groups in every one of my perennial beds, they put on a wonderful early summer show. They play nicely with other plants and are relatively problem free. They self seed so readily, I end up having many to give away or move around, and I can always find a home for more. If you have well behaved pets and children, please consider them for your gardens. They are the perfect cottage garden plant.
Photos courtesy of PlantFiles
Learn About Lupine
Common Disease Problems
Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Cucumber Mosaic Virus: This virus disease is spread by aphids and causes mottling on the leaves, bunching and downcurling of young leaves, small leaves and brown streaking on the stems. Burpee Recommends: There is no cure for this disease. Remove and destroy infected plants. Control aphids which spread the disease. Be careful when working in the garden and do not touch any plant until you have washed your hands or gloves after touching infected plants. Clean tools after working with each plant.
Downy Mildew: This fungus causes whitish grey patches on the undersides and eventually both sides of the leaves. Burpee Recommends: Rotate crops with plants in a different family. Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet.
Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.
Root Rots: A number of pathogens cause root rots of seedlings as well as mature roots. Burpee Recommends: Practice crop rotation and do not plant related crops in the same area for several years. Pull up and discard infected plants. Make sure your soil has excellent drainage. Contact your Cooperative Extension Service for recommendations.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps which feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Lupine Root Weevil: These insects feed on plant roots. The larvae are white curled worms feed on the roots interfering with their ability to take up water and nutrients. They overwinter in plant debris. Burpee Recommends: Handpick adults at night, shake the plants over newspaper to dislodge them. Check under pots where they hide during the day. Check with your Cooperative Extension Service for pesticide recommendations.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack flower petals, leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Many thrips may be repelled by sheets of aluminum foil spread between rows of plants. Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.