How to grow eggplant

Soak the seed in clean water for 24 hours (a full day and night) before sowing — eggplant seed is slow to wake, and soaking helps it come up more evenly.

Make a raised bed about a hand-span high (~20 cm) of fine, clean soil, in a spot that drains well and gets morning sun. Raising it keeps the seedbed from flooding and rotting the seed.

Use sterilised soil — soil you have wetted then covered with a clear plastic sheet in the hot sun for a few weeks, or old nursery soil baked over a fire. Heat kills the soil diseases that flatten young seedlings.

Sow the seed thinly in shallow drills a hand-span (~20 cm) apart, and cover it only as deep as your fingernail (a few mm) — tiny seed buried deep never reaches the light. Water gently with a fine rose.

The seed sprouts in about 8–12 days in warm weather (around 22–28 °C). Keep the bed moist but never soggy, and shade it from fierce midday sun.

Grow the seedlings on for about 5–6 weeks, until they are 8–10 cm tall (about as tall as your palm is wide) with 4–5 true leaves — that is the right size to move to the field.

Start about 5 days before transplanting. Cut back the watering a little — water less often so the seedlings toughen up, but never let them wilt hard.

Take any shade off them and let them stand in full sun, so leaves and stems toughen to field conditions.

If you can, leave them out in the open air and a little wind through the day, bringing them under cover only if a storm threatens.

By transplanting day the seedlings should look sturdy and slightly hardened, not soft and lush — those settle in fastest.

In the two weeks before you transplant, choose ground with a break of at least 3 years from tomato, potato, pepper and eggplant. These cousins pass on bacterial and soil wilts that live on in the soil — a long rotation starves those diseases out.

Pick a well-drained spot and avoid low ground that floods — wet feet rot eggplant roots and spread bacterial wilt fastest. On heavy or flat land, make ridges or raised beds so water runs off.

Clear the weeds and dig the soil over about a spade deep, breaking the clods to a crumbly tilth so roots go down easily.

Work in plenty of well-rotted compost or manure — about two big handfuls (a kilo or so) worked into each planting hole — to feed the soil and help it hold moisture through the long season. Use only well-rotted (dark, crumbly, no strong smell) material.

Mix in the base ('basal') fertiliser — the fertiliser that goes in before planting — carrying phosphorus (P) for roots, plus potassium (K, which builds firm, well-coloured fruit) and calcium (Ca), at the amount your plan gives, before you mark out the planting stations.

Buy stocky, dark-green seedlings about 8–10 cm tall with 4–5 true leaves and a thick stem — not tall, thin, pale or pot-bound (roots coiled tight in the pot) ones.

Check each one for wilting, yellowing or spotted leaves — signs of soil disease already in the seedling — and reject the whole batch if many look sick.

Buy from a nursery that raises seedlings on clean, rotated ground, away from tomato-family crops.

Transplant them within a day or two of buying, and keep them shaded and watered until you do.

Transplant in the late afternoon or on a cloudy day, never in hot midday sun — the cool lets seedlings settle overnight without wilting.

Set the plants at the wide spacing eggplant needs: 50–75 cm apart down the row (about three hand-spans) and 60–90 cm between rows (roughly a stride). A big bush crowded in makes small fruit and traps damp air that breeds disease.

Plant each seedling to the same depth it grew in the nursery — up to its first leaves, no deeper — in a hole big enough for the root ball.

Put the basal (the base fertiliser: N-P-K plus calcium) in the station and mix it with soil first, so the roots don't sit directly on the fertiliser and burn.

Water in well right after planting — soak each plant so the soil settles tight around the roots with no air pockets.

Only plant onto ground with a ≥3-year break from tomato, potato, pepper and eggplant — the rotation you set in field prep is what keeps bacterial wilt out.

Walk the field twice a week from the day after transplanting, covering all corners and the middle — not just the edge by the path.

Cutworms: look for young plants cut clean off at ground level (worst overnight and in the early morning). Scratch the soil near a cut plant and you will find a fat, grey-brown caterpillar curled up — squash it.

Bacterial wilt: look for a plant that wilts in the heat and does NOT recover in the cool of evening, with its leaves still green (not yellowing first). To be sure, cut the stem low down and stand the cut end in a glass of clear water — milky white threads oozing out mean bacterial wilt.

Jassids (leafhoppers): turn a few leaves over and look for tiny green wedge-shaped hoppers that jump when disturbed; their feeding makes leaf edges yellow, curl downward and go bronze.

Count how many plants show fresh damage and note the gaps, so you know whether to gap-fill or act. Act at the first signs — don't wait.

If it fails — you find a bacterial-wilt plant → rogue it (pull it out) at once with a spadeful of the soil around its roots, carry it right off the field, and burn or bury it. Never compost it: there is no cure, and it spreads through wet soil to healthy plants.

About a week after transplanting (5–9 days), walk the rows and mark every station where the seedling has died or failed to take.

Fill each gap with a healthy spare seedling from your nursery, lifted with a ball of moist soil on its roots.

Plant the replacement at the same spacing and depth as the rest, in the cool of late afternoon, and water it in well.

Do it early, so the fill-ins are close in age to the main crop and grow up level with it.

Keep the topsoil moist but never waterlogged for the first two weeks after transplanting — push a finger in and water when the top few cm are dry.

Water every 3–5 days, more often in heat or on sandy soil that dries fast, less in cool weather or heavy soil.

Water at the base of the plants, in the cool of morning or evening, rather than over the leaves — wet leaves invite disease.

Drain off any standing water quickly after heavy rain — eggplant roots rot and bacterial wilt spreads in soil that stays wet.

From about 2 weeks after transplanting, walk the crop twice a week and look closely at about 10 plants spread across the field.

Borer dead-hearts: check the growing tips for shoots that suddenly wilt and droop — a 'dead-heart', where a caterpillar has tunnelled inside. Snap one open and you may find the small pinkish caterpillar and its sawdust-like droppings (frass).

Leaf spot: look on the older, lower leaves for brown-to-grey spots, often ringed like a target or edged with a yellow halo; heavy spotting makes leaves yellow and drop.

Little-leaf: watch for any plant turning bushy with tiny, crowded, pale leaves and short stems that stops growing normally — a disease spread by leafhoppers, with no cure.

Leafhoppers (jassids) & whitefly: turn leaves over for tiny green hoppers, or clouds of tiny white flies that rise when you shake the plant; their feeding yellows and curls the leaves. The leafhoppers also spread little-leaf (the whitefly does not, but it carries other virus diseases).

Write down what you find and where, and act at the first signs — clip bored shoots, rogue (pull out and remove) little-leaf plants, and strip badly spotted leaves.

Every week, from about two weeks after transplanting right through picking, walk the crop looking for wilted, drooping shoot tips (dead-hearts) and fruit with a small hole plugged with sawdust-like droppings.

Cut each bored shoot off about a finger-joint (3 cm) below the damage, into healthy wood, with a knife or secateurs.

Pick off every bored fruit too, even small ones — the caterpillar is still inside.

Carry all the bored shoots and fruit right off the field and burn them or bury them deep. Never drop them between the rows, or on the compost — the caterpillar just crawls back or turns into a moth.

Hang pheromone traps (scent traps that lure the male borer moths) — about one trap every ten strides each way (~100 per hectare) — and change the lure about every 25 days. Rising catches warn you the pressure is climbing.

About 2–4 weeks after transplanting, once the plants are clearly growing away, give the first top-dressing — a feed of nitrogen fertiliser banded beside the growing plants.

Band the nitrogen in a line about a hand's width (~10 cm) to the side of each plant — the amount your plan gives — never heaped against the stem.

Apply on moist soil, after a weeding or a light rain, and cover it with soil or water it in, so it soaks down to the roots instead of gassing off into the air.

Keep the fertiliser grains off the wet leaves — they stick and scorch. Brush any off.

2–4 weeks after transplanting, weed around the plants — hoe shallowly so you don't cut the eggplant's own roots, and pull weeds close to the stem by hand.

For tall or long-fruited types, push a sturdy stake about knee-to-waist high in beside each plant while the roots are still small, so you don't spear the roots later.

Tie the main stem loosely to the stake with soft string or a cloth strip, in a figure-of-eight, leaving room for the stem to thicken.

Keep weeding through the season as needed — a clean field also means fewer places for pests and disease to hide.

Through flowering (from about 6 weeks after transplanting), walk the crop twice a week, checking growing tips, flowers and young fruit on about 10 plants.

Borer: keep checking shoot tips for dead-hearts, and young fruit for the tell-tale hole plugged with sawdust-like droppings — clip and remove them the moment you find them.

Blossom drop: look for flowers falling off without setting fruit. A little is normal; a lot usually means heat, cold nights, or dry soil — so keep the water steady and shade the crop if you can.

Feel a few set fruit — healthy ones swell and shine. Note anything wrong: a dark, sunken, leathery patch at the flower end is blossom-end rot, a sign of uneven watering and calcium shortage.

Write down what you find and act — clip bored shoots and fruit, even out the watering, and spray for the borer only if it crosses the threshold.

From about 6 weeks after transplanting, keep the soil evenly moist right through flowering and fruit set — never let the plants swing from bone-dry to soaked. Even moisture is what carries calcium to the fruit.

Water every 3–5 days (more often in heat), a good soak each time down to the roots, in the cool of morning or evening.

Let the calcium (Ca) from your basal do its job — even watering is what lets the plant move calcium into the fruit; a dark, sunken patch at the fruit's flower end (blossom-end rot) means the water has been too uneven.

Still never waterlog — soak, then let it drain. Standing water at fruit set both rots roots and spreads bacterial wilt.

Spray only when scouting shows the borer over threshold — clipping and trapping come first; the spray is the backup, not the routine.

Rotate the product every time: alternate a selective borer product (such as spinosad or chlorantraniliprole) with Bt (a natural caterpillar-killing bacterium) or neem. Never spray the same one twice running, or the borer becomes immune to it.

Measure the dose with the cap supplied and mix it into a full knapsack (15–20 litres). Spray to wet the leaves (undersides too) and the shoot tips, without letting it drip.

Protect yourself: wear a long-sleeved shirt, cover your nose and mouth, and spray in the cool of the day with the wind behind you, so the mist blows away from you. Keep people and animals out of the field.

Respect the pre-harvest interval — the number of days the label says you must wait between spraying and picking — because you pick this crop every few days. Never spray fruit you are about to harvest.

Wash yourself, your clothes and the sprayer well afterwards, and store the chemical locked away from food, water and children.

Walk the crop twice a week all through picking (from about 2 months after transplanting), checking shoots, fruit and leaves on about 10 plants.

Borer: keep clipping dead-heart shoots and removing bored fruit (the ones with a sawdust-plugged hole) — every pick is a chance to clean them out.

Bacterial wilt: watch for plants that wilt in the heat and don't recover by evening, leaves still green; confirm with the cut-stem-in-water test (milky threads) and rogue them at once, soil and all.

Red spider mite (in hot, dry spells): look on the leaf undersides for fine pale speckling and cobweb-like webbing; badly hit leaves go dusty-bronze and dry. Wash the undersides with water or treat with neem, and keep the crop well watered.

Leaf spot: strip off badly spotted lower leaves to slow the disease, and never work the crop while the leaves are wet.

Every 2–3 weeks through the picking season (from about 2 months after transplanting), band another small feed of nitrogen (N) beside the plants — little and often keeps the long crop producing.

Band it about a hand's width (~10 cm) to the side of each plant (the amount your plan gives), on moist soil, and cover or water it in.

Keep the grains off the wet leaves and the fruit, and keep feeding for as long as the plant is cropping well.

If the leaves turn pale and growth slows, the crop is nitrogen-hungry — don't skip these feeds.

Start picking from about 2 months after transplanting, and go through the crop every 2–3 days — fruit comes ready fast, and a big plant carries many at once.

Pick each fruit at full size for its type, with a bright, glossy skin. Press it gently with your thumb: ready-to-pick flesh springs back; if the dent stays, it is over-mature.

Cut the fruit off with a short piece of stalk, using a knife or secateurs — do not pull or twist (it tears the plant), and mind the prickly green cap (calyx) on many types.

Lay picked fruit gently in a basket in the shade — the skin bruises and scratches easily.

Pick every fruit that is ready on each round, even ones you'll only sell tomorrow — leaving ripe fruit on the plant slows new flowering.

If it fails — the skin has gone dull and the seeds inside are hard and brown (and the flesh stays dented) → that fruit is over-mature and bitter: cut it off and discard it or feed it to animals, and pick more often so no fruit ever gets that far again.