How To Grow Organic Eggplant?
AWESOME EGGPLANT INFO
- It is good to know, for many reasons, that if you’re growing eggplant, it’s related to tobacco, tomatoes, and potatoes.
- Growing eggplant for food originated in the regions around India, Nepal, Pakistan, Bangladesh, and Sri Lanka.
- Although in modern times you’ll find most gardeners growing purple eggplants, there are also white, yellow, green, and orange varieties that are making a comeback.
- Our Ukrainian neighbor, Angelina, introduced us to a delicious eggplant/tomato salsa that has become our favorite sweet salsa. Contact us if you want the recipe. We’ll be adding it later this year to this website as we expand our offerings.
WHEN TO PLANT
- In most parts of the country eggplants should be started from seed indoors, and then transplanted into the garden.
- Some hybrid varieties take as little as 55 days to mature, but most open-pollinated or heirloom varieties (from which seeds can be saved from) need 70-100 days of warm weather, preferably 80°F and above, to reach maturity.
- In northern or cooler climates, start seeds indoors 6 weeks before the last frost date and transplant at least 2 weeks after the last frost date (that will put your plants at about 8 weeks when transplanting). In our short growing climate, we wait until June 1st to transplant eggplant into our garden.
- Eggplants growing in cold soil or exposed to chilly weather grow poorly. Plant growth will be stunted and leaves can turn yellow and die (we learned this the hard way our first year). Even when warm weather returns, plants may not fully recover.
- Eggplants are more susceptible to damage from low temperatures (55°F and below) than tomato plants. Even a very light frost will permanently retard or even kill eggplant.
- If you live in a mild winter area with a long growing season, you can do a second planting in the mid-summer, to be harvested late in the fall.
WHERE TO PLANT
- To grow eggplant successfully, they’ll need steady, warm growing conditions for at least three months.
- Eggplant prefers organically rich, well-drained, sandy soil and at least 8 hours of full sun per day.
- You can plant eggplant seeds directly in your garden in hot climates.
- Eggplant performs best in daytime temperatures of 80-90°F and nighttime temperatures no lower then 70°F.
PREPARING THE SOIL
- Eggplant grows best in soil with pH between 5.5 and 7.5.
- Incorporate well-rotted manure and compost, or an organic garden fertilizer before transplanting.
- Addition of manure or compost can add micro-nutrients and organic matter to soil.
- When you add well-composted manure to the growing area, it helps the soil to retain needed moisture and provides a lighter, looser soil structure that is easier for your eggplant to grow in.
- Add up to 2-4 inches of well-composted organic matter. Work this into the top 6 inches of soil.
- Add more if you have heavy clay soil, this will help to lighten and improve the nutrient quality of your soil.
- If the pH is too low, add lime.
- Covering the planting site with black plastic mulch 2 weeks prior to transplanting eggplants will help heat the soil; transplanting won’t be as much of a shock to your plants.
- Mounding up your soil to make raised beds will also help the soil to heat up quicker in the spring.
CHOOSING THE RIGHT SEED VARIETIES FOR YOUR AREA
- Verticillium wilt (VW) is the most common disease of eggplant. Look for varieties that are resistant to this disease.
SEEDS AND GERMINATION
- Optimal germination temperature is 80° tp 90°F with a minimum of 70°F.
- Cold temperatures (below 65°F) will stop plant and root growth.
- Once you’ve purchased your seeds they should be good for about 5 years.
GETTING STARTED INDOORS
- Soak the seeds overnight before planting or sprout them by placing seeds inside a damp paper towel placed inside a sealed plastic bag and set in a warm location.
- Use a sterile germination mix that contains vermiculite, peat or sphagnum moss. Moisten the mix before you plant your seeds.
- In a flat, fill with at least 2” of sterile seed germinating mix. Plant seeds ¼” deep with ½” space either side. Cover and keep moist but not soggy.
- Place flat in a warm location where soil temperatures can maintain a minimum of 70°F for germination.
- Placing heating mats under your flat can help keep temperatures consistent and up where they need to be. You can also try placing your flat on top of an insulated water-heater, or an upright freezer may be sufficient. I have even had success placing my trays on top of the hanging fluorescent lamps on my grow stand.
- Carefully monitor soil mix moisture levels. Using a source of heat will dry soil out quicker and potentially prevent any seeds from germinating.
- Thin seedlings after the first true leaves appear by cutting unwanted seedlings at their base. Space seedlings 2 inches apart.
- When seedlings have their second set of true leaves, block out the plants in the flat (cut in between them both vertically and horizontally as though you were cutting brownies into squares). This will encourage new root growth close to the plant which will minimize root disturbance when transplanting.
- In one week after blocking out, transplant them individually to 3 to 4 inch pots.
- Eggplants are also good for container growing, with one plant per 3 to 5 gallon pot or container with a depth of at least 12 inches.
- If using terra cotta pots, keep in mind that they absorb moisture and your plants will need to be monitored more frequently for watering. This will obviously be more of an issue in hotter climates.
- Eggplant seedlings need 14 to 16 hours of lighting per day with the grow-lights or fluorescent bulbs placed 2 to 3 inches above the plants. This will ensure plants grow large and healthy. See article on Indoor Lighting.
TRANSPLANTING EGGPLANT TO YOUR GARDEN
- Eggplant grows best if transplanted when plants have 6-9 leaves and a well-developed root system. This requires 6 to 8 weeks of growing indoors.
- When the outside night-time air temperatures are maintaining 65-70°F, and your plants are 6 to 8 weeks old, begin to harden off your seedlings.
- Start with one hour of direct sun and gradually expose them to more sunlight daily over the next week or two, bringing them up to equivalent daylight hours. Bring your plants indoors in the evening if night temperatures are dropping below 65°F.
- Eggplant needs to be babied. Do not reduce watering or expose the plants to cold temperatures when hardening off. Doing so can cause woody stems and a poor fruit yield.
- If temperatures are not warm enough in 6 to 8 weeks, transplant your seedlings into larger pots and wait to harden off until the outside temperatures are consistently warm enough.
- Water the seedlings thoroughly approximately one hour before you plan to transplant. The soil should be noticeably moist, but not soggy.
- If you water your plants well about an hour before transplanting, the soil will stay firmly around the roots causing fewer disturbances while you’re putting them in the ground.
- Transplant on a cloudy day: Bright sun can hurt newly planted seedlings, so always plan to transplant on an overcast day, late in the afternoon or in the evening.
- Eggplants should be placed so that the shoots are at the soil line as they were before transplanting.
- Water your eggplant thoroughly once you’ve transplanted to ensure they’ll have enough moisture to root in your garden.
- Provide shade the first day or two for the newly transplanted eggplant seedlings and protect from wind.
- Space plants 18 to 24 inches apart in the row depending on fruit size. Allow 30 to 36 inches between rows or you can space plants 2½ to 3 feet apart in all directions.
- Mulch immediately after transplanting, and gently hand pull any invading weeds.
- Pour 1 to 2 cups of compost tea around each plant, and firm the soil gently.
PLANTING EGGPLANT SEEDS DIRECTLY TO YOUR GARDEN
- Be sure you have enough warm growing days to successfully grow eggplant to maturity from seed planted directly in your garden.
- If you live in such a climate, the earliest you should plant seeds outdoors is 2 weeks after the last spring frost, but your best indicators are weather conditions and soil temperature.
- Eggplant is easily harmed by cold temperatures. Hold off planting seeds until the soil has warmed to 70°F and day temperatures remain above 65°F at the bare minimum.
- Sow seeds very shallow, about 1/4 to 1/2 inch.
- Space plants 18 to 24 inches apart in the row depending on fruit size. Allow 30 to 36 inches between rows or you can space plants 2½ to 3 feet apart in all directions.
GROWING YOUR EGGPLANT SUCCESSFULLY ‘TIL HARVEST
- Keep the soil moist to promote maximum growth.
- When plants are about 6″ high, nip back the growing tip to encourage branching.
- Pinch off the top of the plant when it’s about 18 inches tall to encourage it to bush out.
- Once you have three or four fruits set, it will be time to start removing any further side shoots as they develop. This helps to divert the energy of the plant to where it is most needed.
- Pinch off blossoms 2 to 4 weeks before first expected frost so that plants channel energy into ripening existing fruit, not producing new ones.
- Eggplants are heavy feeders, but avoid feeding too much nitrogen. It will encourage lush foliage growth at the expense of fruit.
- In hot regions where the temperature tops 100°F, it’s best to protect plants with shade covers.
- When the eggplants bloom, apply more liquid fertilizer and repeat monthly.
- Use hot caps over your plants for cool nights (below 65°F) to protect .
- Row covers can be placed over plants to protect from low night temperatures and some insect pests. If you use row covers for eggplant, they need to be supported up above the plant by rounded wire, an a-frame support, or some other method to keep the fabric from laying directly on the plants.
- Great care should be taken to avoid damage or breakage to the growing point of the young seedlings which will severely slow the growth and production of the plant.
- Remove covers when temperatures are above 85° F to prevent heat damage.
- If you have a couple warm weeks into fall, you can extend your harvest by covering your plants with a row cover.
- Jenny’s Tip – When you’re growing eggplant, spray your plants every couple of weeks with a liquid organic leaf spray fertilizer. We highly recommend Organic Garden Miracle™. It naturally stimulates your garden plants to produce more plant sugar in the photosynthesis process. That in turn creates a more robust plant, more produce from your garden, and better and sweeter flavor. And they have a really good warranty!
WEEDING AND MULCHING
- Use black plastic (known as plastic mulch) to keep the ground warm before planting in cooler climates. Plastic mulches allow earlier planting and maturity, especially with transplants.
- After preparing the soil, lay the plastic over the planting area, secure the edges with soil, and cut holes for the transplants.
- Using the combination of plastic mulch and row covers, eggplant can be set out before the last frost date if soil and air temperatures are monitored carefully.
- Once soil temperatures have reached 75°F, replace plastic mulch with organic mulches.
- Mulching with herbicide-free grass clippings, weed-free straw, or other organic material will help to prevent weed growth, and decrease the need for frequent cultivation.
- Do not apply organic mulches around the plants until soils are warmer than 75ºF. Applying too early keeps the soil cool, resulting in slow growth and shallow rooting.
- The roots of eggplants are very close to the surface of the soil, so it’s important not to cultivate too deeply. Cultivate just deep enough to cut the weeds off below the surface of the soil.
WATERING YOUR EGGPLANTS
- For best production, plants need 1 to 1½ inches of water a week.
- Soak the soil thoroughly when watering, There is little or no value in light watering that only wets the soil surface.
- Apply 1 to 1 1/2 inches once a week during the growing season. If your soil is sandy, it may require more than one watering a week.
- Use drip irrigation if possible. Irrigate so that moisture goes deeply into the soil.
- Irregular watering (under or over) can cause tough leathery fruit or root rot.
COMPANION PLANTING AND ROTATION CONSIDERATIONS
- Here is an example the inexact science of companion planting:
- Eggplant is a member of the nightshade family and some gardeners say it grows well with peppers. These plants like the same, warm growing conditions.
- But, since eggplant is related to peppers (as well as tomatoes and potatoes), it attracts the same type of pests. So, on the contrary, some suggest avoiding planting eggplant and peppers in close proximity. I suggest trying both and see what works best in your area.
- Beans planted with eggplants repel beetles which would otherwise attack the eggplant. Pole beans can provide shade and wind protection.
- Marigold deters nematodes. If you grow marigolds as a pest repellent for your eggplant, it’s best not to grow beans as the companion vegetable, since marigold can be an herbicide to certain beans.
- Tarragon and Thyme both aid in improving flavor and growth in vegetable plants and help repel pests.
- Fennel is a bad companion and is toxic to most garden plants. Depending on the plant, it can inhibit growth, cause bolting, or even kill plants growing nearby. Dill is the only garden plant that is not affected.
- Tomatoes, peppers, and potatoes, eggplant are in the nightshade (Solanaceae) family. These plants should not be planted in the same location the following year to avoid soil-borne diseases.
- Crops should also be alternated due to soil depletion or pest attraction.
- Planting in the same location once every 3-4 years is recommended.
HARVESTING YOUR EGGPLANT
- If you grow heirloom eggplant varieties, you know that eggplant comes in a rainbow of colors, shapes, and sizes, so picking when an eggplant is dark purple to black and 6 to 8 inches long will not always apply.
- Some varieties, such as Thai eggplants, can be round like a small ball or long like young zucchini and are not a solid color when ripe.
- The best indication of when to pick a ripe eggplant is when the skin has a glossy sheen and a correct firmness (explained below). It also helps to know the variety’s expected ripe color and size.
- To test for correct firmness, press the skin. If the flesh is hard and does not give, the eggplant is immature and too young to harvest. If the thumb indentation remains and feels spongy, the eggplant is over mature with hard seeds and flesh that becomes stringy. You want a firmness between the two.
- To harvest, cut the stem with a knife or pruning shears.
- If you cut open an eggplant fruit and find that the seeds inside have turned brown, the fruit is past prime quality and the flavor may be bitter.
- The best way to avoid this is by picking fruits on the young side, when they are 1/3 to 2/3 of their fully mature size.
- Wear gloves. Eggplant has small prickly thorns on the stems and under the leaves.
- Eggplants bruise easily so harvest gently. Always cut the eggplant with the cap and some of the stem attached.
- Eggplants do not hold up well in cool temperatures so the refrigerator may not be your best option. If you do choose to store them in the refrigerator, wrap them in plastic and use the vegetable within the next couple days.
- Before using, check that the stem and cap are still a greenish color and no brown spots have developed on the skin.
- For the longest fresh storage, mature eggplants will keep for approximately 1 week if held at 50-55°F and 90% humidity.
- Eggplant can be dried in a dehydrator. Choose freshly picked, ripe eggplant (following the same guidelines under Harvesting). Cut into ¼ to ½ “ thick round slices or ½” cubes for drying.
- Eggplant is dry when it is brittle and wafer-like. To rehydrate, soak in water for at least 30 minutes.
- An old-fashioned way to dehydrate eggplant is to string-dry the round slices. After slicing, cover them with coarse salt for a few hours to draw out moisture. Using a sterile needle and a string (do not use wire which can rust), string the rounds. Hang both ends of the string (so it is hanging horizontally) out of direct sunlight. Space apart each slice to allow good air circulation and avoid sticking.
NATURAL AND PREVENTATIVE SOLUTIONS TO PESTS
- Flea beetles are eggplant’s worst pest.
- These tiny beetles chew holes in leaves and stems of seedling which is when they’re most vulnerable, and can weaken or kill the plants.
- Row covers are effective if they’re completely sealed with dirt or sandbags.
- Check under your row covers to make sure you beat the beetles to your plants and to make sure the weeds aren’t choking your plants either.
- Proper nutrition and watering also helps your plants resist flea beetles. Ridding the area of bindweed and wild mustard also helps.
- One effective remedy for these beetles is powdering your plants with diatomaceous earth. It only works if dry, though, so if it rains or you irrigate you’ll need to re-dust your plants.
- If plants become infested, spraying Beauveria bassiana or spinosad may knock back the population of flea beetles and save your plants.
- Colorado Potato Beetles are a black and yellow striped insect that lays bunches of yellow eggs on the underside of eggplant leaves.
- Hand-picking the beetles and their eggs is the most effective way to rid your plants of these pests. Drop them into a pail of soapy water to drown them quickly.
- Tomato hornworms are another pest that afflicts eggplant. They’re an approximately 4 inch long green caterpillar with white stripes with a black “horn” on their last abdominal segment.
- The adult moths are a gray-brown mottled color and have yellow spots on their abdomens and about a 4 to 5 inch wingspan. The hind wings have light and dark stripes.
- They prefer tomatoes, but will also defoliate potatoes, eggplant and peppers.
- Check your garden a couple times a week and handpick any hornworms you find. You can drown them in a bucket of soapy water, or, like we do, feed them to your chickens – they absolutely love them!
- Keeping your garden weed-free helps to keep this pest under control, as well as rototilling your garden in the fall.
- Braconid wasps are one of nature’s natural antidote to hornworms. If you see hornworms with tiny white cocoons on them, leave those alone as those are the parasitic offspring of these wasps and they’re in the process of killing these caterpillars.
- Spider mites are another tiny pest that causes your leaves to look stippled yellow. You can spray these little pests off with a stream of water.
- Cutworms will attack eggplant – usually early in the season when the plants are young and tender – at the soil line, killing the plant. They don’t eat the tops of the plants.
- Cutworms vary in color, gloss, and patterns (spotting or striping); they’re black, green, gray, brown, pink, or tan, with lots of variations in those colors.
- If you disturb a cutworm, they’ll curl up in a ball.
- The adult moths are also varied in color and pattern, but are typically have about a 1.5 inch wingspan. The forewings are typically striped or spotted and are darker than their rear wings. Their colors range from white to brown to black to gray.
- To spot cutworms, check around your plants, especially if one is wilting, in the evening. Move clods or other debris away from the base of your plants to find hiding cutworms.
- Look for cutworm droppings on the ground that’ll be a sign that cutworms have been eating your plants.
- It helps to make sure there’s no weeds or decaying plants on the surface of the soil where small cutworms thrive. Rototilling your soil helps to kill larvae by turning decayed plants into the soil where they’re unavailable for cutworm larvae to feed on.
- Don’t use green manure as the adult moths lay eggs in it; rather, use composted manure.
- If you rototill your garden in the fall, it helps to expose or get rid of larvae and pupae.
- If you have just a few plants, you can make a cardboard or aluminum foil collar to dig in a few inches around the base of your eggplant; this makes a physical barrier to keep cutworms from feasting on the base of your plants.
- Diatomaceous Earth is very effective against cutworms, but remember that it only works if it’s powdery and needs re-applied if your plants and soil become wet.
- Another pest that afflicts eggplant is spider mites.
- Spider mites are very tiny and appear as red specks on your sage. Heavy infestations of spider mites will destroy leaves.
- As they’re so small, it’s difficult to see these pests and it’s more likely that you’ll see their damage before you see them. The damage appears as yellow stippling in your leaves.
- A spray of water will often knock these tiny pest off your plants when you begin to see the stippling.
- You can purchase predatory mites that will rid your garden of spider mite but don’t bother your plants.
- If the spider mites get to profuse, you can use diatomaceous earth, pyrethrins, or organic insecticidal soaps. Dust or spray your plants weekly until the problem disappears.
- Eggplant likes consistency, and problems like “flower abortion” (flowers dropping), blossom end rot, and sunburn can be avoided by consistent watering and row covers if the weather is over 90°F for long periods of time.
- Verticillium wilt is common in eggplant and causes the plants to yellow and wilt. Your best defense is crop rotation and purchasing resistant varieties.
- Early blight is a less common eggplant ailment, causing leaf spots or loss of leaves and fruit in more severe cases.
- Typically this blight appears in wet years. Planting resistant varieties is your best defense, and over-head watering only early in the day if you don’t have drip irrigation.
- Soil that is balanced with good nutrients also is beneficial in resisting blight.
- You can also make an organic fungicide spray using bicarbonate of soda (baking soda). In a gallon of water add a couple drops of organic olive oil, a couple drops of environmentally-friendly liquid soap, and 3 tablespoons of baking soda. Spray it on your eggplant leaves to effectively control fungal diseases.
- Late blight is more severe than early blight. Initially you’ll see dark green lesions on the lower plant leaves, and you may see a white fuzzy fungus on the underside of the leaves. If left untreated, these outbreaks can wipe out your eggplant crop.
- Use the above anti-fungal spray if an outbreak begins. Rotate your crops away from the area next season.
- Remove and destroy infected leaves and/or plants.
- Use early in the day watering, weed control, and plant blight resistant varieties to reduce the risk of late blight.
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