Pests
Symptoms The leaves are peppered with lots of tiny round holes, as if hit by birdshot. It hits young plants hardest and can devastate seedlings. Touch the plant and you will see tiny dark beetles jump away.Tiny shot-hole punctures riddle the leaves, a scatter of small round holes that is the classic flea-beetle signature on eggplant. Damage is by far most severe on seedlings and young transplants, whose small leaf area a heavy infestation can shred or kill outright; established plants tolerate considerable feeding. Brush a plant and the small dark beetles spring away like fleas. Cause Small dark beetles that jump like fleas and chew tiny holes in the leaves. They are most active in spring and love eggplant, so they target young plants early in the season.Several Epitrix flea beetle species that feed on eggplant foliage, overwintering as adults in debris and emerging to attack the earliest, most vulnerable plants in spring. Eggplant is a strongly preferred host, and the beetles concentrate on it, which is why flea beetles are the defining early-season eggplant pest. Organic treatment Cover young plants with a light row cover until they are big and strong, then take it off when they flower. Setting out larger transplants helps them outgrow the damage. For heavy attacks on seedlings, an organic spray such as spinosad or a kaolin clay coating helps.Protect transplants with floating row cover until they are large and vigorous, removing it at flowering. Set out stout, well-hardened transplants rather than tiny seedlings so plants can outgrow the damage, and treat heavy early infestations with spinosad or kaolin clay. Mature plants rarely need treatment. Prevention Cover plants early with row cover, set out larger transplants into warm soil so they grow quickly, and clear away weeds and old plant debris where the beetles hide over winter. A border of nasturtiums can lure them away.Use row cover from transplanting, delay setting plants out until the soil and air are warm so they grow away fast, and clean up crop debris and weeds that harbor overwintering adults. A nasturtium or other trap planting at the bed edge can draw beetles off the crop.
Symptoms Striped yellow-and-black beetles and plump red larvae with black spots eat the leaves, sometimes stripping a plant bare. Eggplant is one of their favorite foods. Check the undersides of leaves for clusters of orange-yellow eggs.Rounded yellow-and-black-striped adults and humpbacked, brick-red larvae with rows of black spots chew the leaves, and eggplant is a favorite host. Both stages feed voraciously and populations build fast, so an unmanaged infestation can defoliate plants and cut yield sharply. Look for clusters of orange-yellow eggs on leaf undersides. Cause A striped beetle whose larvae and adults both feed on eggplant and potato leaves. They overwinter in the soil, show up as plants get going, and multiply quickly through the summer.Leptinotarsa decemlineata, a Solanaceae specialist that prefers potato and eggplant. Adults overwinter in the soil and nearby debris and move in as plants establish; left alone they go through multiple generations a season and quickly resist many insecticides, making non-chemical control important. Organic treatment Pick the beetles, larvae, and egg clusters off by hand and drop them in soapy water, checking every day or two. Squash the orange egg clusters under the leaves. For heavy infestations, an organic spray such as spinosad or Bt (the tenebrionis strain) works on the young larvae.In a home garden, hand-pick adults, larvae, and egg clusters daily into soapy water, which keeps small plantings clean. Crush egg masses on leaf undersides, and where pressure is high apply spinosad or Bacillus thuringiensis var. tenebrionis to young larvae. Rotating away from last year's nightshade bed cuts the overwintered population. Prevention Do not plant eggplant where potatoes, tomatoes, or eggplant grew last year, since the beetles come up from the soil there. Cover young plants with row cover, and a thick straw mulch makes it harder for the beetles to reach them.Rotate eggplant well away from where potatoes, tomatoes, or eggplant grew last year, since the overwintered adults emerge near old hosts. Row cover on young plants excludes the colonizers, and a thick straw mulch hinders the adults that walk in from the soil.
Symptoms Tiny soft green or black insects gather on new growth and the undersides of leaves, making them curl and yellow, often with a sticky film and black mold. They can also spread plant viruses.Colonies of small soft-bodied insects, often green peach aphid, cluster on growing tips and leaf undersides, causing leaves to curl, pucker, and yellow, with sticky honeydew and sooty mold following. Beyond direct feeding, aphids transmit mosaic and other viruses that mottle and distort the foliage. Cause Small sap-sucking insects that multiply quickly in warm weather, especially on soft growth from too much fertilizer. The sticky honeydew they leave grows black mold.Several aphid species, predominantly green peach aphid, that suck sap and reproduce rapidly in warm weather, building up fast on soft, over-fertilized growth. The honeydew they excrete fosters sooty mold that shades the leaves. Organic treatment Blast them off with a strong spray of water and treat the undersides of the leaves with insecticidal soap, repeating every few days. Ladybugs and other helpful insects eat aphids, so welcome them.Knock colonies off with a strong jet of water and spray insecticidal soap or horticultural oil with thorough coverage of leaf undersides, repeating every few days. Conserve ladybugs, lacewings, and parasitic wasps, which usually bring aphids under control. Prevention Do not over-fertilize with nitrogen, check the undersides of leaves regularly, and let helpful insects do their work instead of spraying everything.Avoid excess nitrogen, which drives the soft growth aphids favor, scout leaf undersides and growing tips, and support natural enemies rather than spraying broadly. Reflective mulch deters aphids from young plants.
Symptoms The leaves look dusty or speckled with tiny yellow dots, and in bad cases you see fine webbing underneath. The leaves can bronze and dry out. Mites love hot, dry weather.Fine yellow stippling speckles the leaves, which may bronze, dry, and drop, and in bad infestations fine webbing appears on leaf undersides. Two-spotted spider mites thrive in hot, dry weather, exactly the conditions eggplant is grown in, so mite pressure often peaks in midsummer. Cause Tiny mites, almost too small to see, that feed on the undersides of leaves and thrive in hot, dry, dusty conditions. They build up fast in summer.Tetranychus urticae and related mites that feed on the lower leaf surfaces with piercing mouthparts. Populations explode in heat and drought and on dusty, water-stressed plants, and can build quickly on eggplant in summer. Organic treatment Spray the undersides of the leaves with a strong jet of water every day for a week, then follow up with insecticidal soap or horticultural oil if needed. Keeping plants well watered helps, since stressed plants are hit hardest.Spray the leaf undersides with a strong jet of water repeatedly to disrupt colonies, then apply insecticidal soap or horticultural oil to the undersides, repeating every few days. Keeping plants well watered and raising humidity discourages mites; predatory mites help under heavy pressure. Prevention Keep plants well watered in hot weather, hose dust off the leaves now and then, and avoid spraying broad insecticides that kill the helpful bugs that eat mites.Keep plants well watered in hot weather, since drought-stressed plants are most vulnerable, avoid dusty conditions, and avoid broad-spectrum insecticides that kill the predators holding mites in check.
Symptoms The tops of the leaves look pale and stippled, and underneath you find dark sticky specks and small insects with lacy-looking wings. Bad infestations brown and curl the leaves.Leaves develop a pale, yellow-stippled or bleached look on top, while the undersides carry dark, varnish-like specks of excrement and the small, lacy-winged adults and spiny nymphs. Heavy feeding browns and curls the foliage and can stunt the plant, and lace bugs are fairly eggplant-specific. Cause A small flat insect with lacy wings that feeds in groups on the undersides of eggplant leaves, sucking out the juices. It is most active in warm weather.The eggplant lace bug (Gargaphia solani), a true bug that feeds in colonies on leaf undersides with piercing-sucking mouthparts. It overwinters in debris and is most damaging in warm weather, with several generations a season. Organic treatment Check the undersides of the leaves and spray any colonies directly with insecticidal soap or horticultural oil, making sure to coat underneath. Pick off and destroy the most badly affected leaves.Scout leaf undersides early and treat colonies directly with insecticidal soap or horticultural oil, which reach the soft nymphs, covering the undersides thoroughly and repeating as needed. Remove and destroy the worst-infested leaves. Prevention Clear away old plants at the end of the season, move eggplant to a new spot each year, and check the undersides of the lower leaves early so you catch the bugs before they spread.Clean up crop debris at season's end to remove overwintering sites, rotate eggplant, and scout the undersides of lower leaves from early in the season so colonies are caught while small.
Symptoms Whole leaves vanish overnight, leaving just the veins, with dark droppings on the leaves below. The cause is a large green caterpillar that hides against the stems, easier to spot by its droppings than by sight.Large sections of leaf, and sometimes whole shoots, are stripped down to the veins overnight, with dark pellet droppings on the leaves below. The culprits are big green tomato or tobacco hornworms, up to four inches long, that blend into the stems and are easiest to find by their frass. Cause Big green caterpillars, the young of large moths, that feed on eggplant and tomato leaves mostly in mid to late summer. Even a few can strip a lot of foliage.Tomato and tobacco hornworms, the larvae of large sphinx moths, which feed on solanaceous foliage including eggplant from midsummer on. A few caterpillars can do conspicuous damage given their size. Organic treatment Pick the caterpillars off by hand and drop them in soapy water. If you find one covered in small white capsules, leave it, those are parasitic wasps that will do the work for you. An organic Bt spray works on the smaller caterpillars.Hand-pick the caterpillars, which is effective in a home garden, and apply Bacillus thuringiensis to younger larvae where numbers are high. Leave any hornworm studded with white parasitic-wasp cocoons in place, since the wasps will kill it and breed more. Prevention Turn the soil at the end of the season to destroy the pupae, watch for droppings and missing leaves from midsummer, and welcome the helpful wasps that attack hornworms.Till the soil in fall to destroy overwintering pupae, scout for frass and stripped leaves from midsummer, and encourage the parasitic wasps and other natural enemies that keep hornworms in check.
Diseases
Symptoms Leaves turn yellow and wilt, often on one side of the plant first, then brown and drop while the plant stunts. Cut a wilting stem and you may see brown streaks inside. It is the most common serious eggplant disease.Lower and outer leaves yellow, often in a wedge or one-sided pattern, then wilt, brown, and drop, working upward as the plant stunts and fails to size its fruit. A cut through a wilting stem shows tan-to-brown streaking in the water-conducting tissue. It is the most common and damaging eggplant disease in much of the country. Cause A soil fungus that infects the roots and blocks the plant's water pipes, so it wilts even when watered. It lives in the soil for years and attacks many crops, especially the nightshade family.Verticillium dahliae, a soilborne fungus that infects the roots and clogs the vascular system, so the plant wilts despite moist soil. It persists in soil for years as resting structures, has a wide host range across the Solanaceae and many other crops, and is favored by cool-to-moderate soil temperatures. Organic treatment There is no cure once a plant has it, so pull and destroy infected plants. The real answer is prevention: rotate your crops and choose resistant or grafted plants next time.There is no cure once a plant is infected; remove and destroy affected plants. Management is preventive and centered on rotation and resistant or grafted plants, since the fungus cannot be eradicated from infested soil by home-garden means. Prevention Plant eggplant in soil with no recent history of the disease, rotate away from tomatoes, peppers, and potatoes, and look for resistant or grafted plants. Keeping plants healthy with steady water and feeding helps them cope.Do not plant eggplant where verticillium-susceptible crops (tomato, pepper, potato, eggplant, and many others) have grown, rotate on a long cycle, choose tolerant varieties or grafted plants on resistant rootstock, and keep plants vigorous with steady water and balanced feeding. Solarizing infested beds can lower inoculum.
Symptoms Pale sunken spots on the fruit spread quickly into soft, rotting patches, and the disease can also spot the leaves and rot the stem near the base. It is worst in warm, wet weather and later in the season.Pale, sunken spots appear on the fruit that rapidly enlarge to soft, spongy, rotting areas, sometimes shrinking the fruit into a dry mummy; the disease also causes grayish leaf spots and a collar rot that can break young stems an inch or two above the soil line. It is most damaging in warm, wet weather and toward fall. Cause A fungus carried on seed and in old plant debris that spreads in warm, wet weather. It can come in on infected seed, so starting clean matters.Phomopsis vexans, a fungus that is both soil- and seedborne and overwinters on crop debris. Warm, humid conditions and splashing water spread it, and infected seed or volunteer debris often starts an outbreak, so clean seed and rotation are central to control. Organic treatment Pick off and throw away infected fruit and plants right away. Keep the leaves and fruit dry by watering at the soil, and use a labeled fungicide if it is spreading. Rotted fruit cannot be saved.Remove and destroy infected fruit and plants promptly to limit spread, and where the disease is active apply a labeled fungicide, keeping foliage and fruit as dry as possible. There is no rescue for badly rotted fruit. Prevention Use clean seed and healthy transplants, do not plant eggplant in the same spot for about four years, water at the soil instead of over the leaves, and clean up old plants at the end of the season.Start with clean, treated, or resistant seed and disease-free transplants, rotate eggplant out of the bed for about four years, water at the soil rather than overhead, mulch to limit splash, space for airflow, and remove crop debris at season's end.
Symptoms The plant wilts and collapses suddenly even though the soil is wet, without much yellowing first. If you cut the stem near the base, the inside looks brown, and a cut stem held in a glass of water gives off milky strands. It is mainly a problem in the hot, wet South.Individual leaves, then whole plants, wilt and collapse suddenly even though the soil is moist, with little of the yellowing that precedes verticillium. Cut low on the stem and the pith is discolored reddish-brown; suspended in clear water, a cut stem streams milky bacterial ooze. It is most serious in hot, wet soils of the South. Cause A soil bacterium that gets into the roots and blocks the plant's water flow, so it wilts fast. It lives in warm, wet soil and spreads in water and on tools.Ralstonia solanacearum, a soilborne bacterium that invades the roots and plugs the vascular tissue. It survives in soil and infected debris, spreads in water and on tools, and is favored by high soil temperature and moisture, so it is most damaging in warm, wet regions. Organic treatment There is no cure, so pull and destroy any plant that wilts from it, and clean your tools. The real fix is prevention next season.There is no cure; remove and destroy wilted plants promptly to limit spread, and disinfect tools. Because it persists in soil, management is preventive, through rotation, resistant or grafted plants, and improved drainage. Prevention Do not plant eggplant where tomatoes, potatoes, or eggplant grew in the last three years, improve drainage in wet spots, and look for resistant or grafted plants if this disease is common where you live.Avoid planting eggplant where tomato, potato, or eggplant grew in the previous three years, choose resistant varieties or graft onto resistant rootstock in problem areas, improve drainage, and avoid moving infested soil or working among wet plants.
Symptoms Dark, wet-looking patches appear on the stems, leaves, or fruit, and the plant can wilt and die quickly. The fruit can rot, sometimes with white fuzzy growth. It strikes in warm, wet, poorly drained ground.Dark, water-soaked lesions and streaking develop on stems, leaves, or fruit, and a plant can collapse and die rapidly once the stem is girdled. Fruit rots with a firm, sometimes white-cottony decay. It flares in warm, wet, poorly drained conditions and after heavy rain or flooding. Cause A mold-like disease that lives in wet soil and spreads in splashing water, attacking plants in warm, soggy conditions. It moves fast once it starts.Phytophthora species (such as P. capsici and P. nicotianae), water molds that thrive in saturated soil and spread in splashing and running water. They survive in soil and debris and move fast in warm, wet weather, especially on heavy or poorly drained ground. Organic treatment Pull and destroy affected plants and fruit, and fix the drainage. There is no good home cure once it takes hold, so prevention is what matters.Remove and destroy affected plants and fruit promptly, and improve drainage immediately. There is no effective home-garden cure once plants collapse, so control is preventive and drainage-based. Prevention Plant on raised beds or mounds so water drains away, avoid wet low spots, water at the soil, and keep fruit off soggy ground. Rotate away from peppers, tomatoes, and squash.Plant on raised, well-drained beds or hills, avoid low spots that stay wet, water at the soil rather than overhead, mulch to limit splash, rotate away from solanaceous and cucurbit crops, and keep fruit up off saturated soil.
