How to grow tomato

Pick a fresh spot in full sun that has not grown tomato, pepper, potato or eggplant recently — these cousins share the same soil diseases.

Build a raised bed, at least one hand-span high (≈20 cm) and about a stride wide, so water drains away fast and never sits on the roots.

Sterilise the soil to kill the damping-off fungus and nematodes. The method that fits this week: pile dry grass over the bed and burn it off a day or two before you sow. (Solarising — covering the wet bed tightly with clear plastic for 4-6 weeks of hot sun — also works, but it is slow: you must start it well over a month ahead, so it only helps if you planned this bed weeks in advance.)

Mix in well-rotted compost to feed the seedlings — never fresh manure, which burns the tiny roots and carries disease and weed seed.

Rake the top fine and level, so the small seed sits evenly and water spreads without washing it into piles.

Buy certified seed in a sealed, labelled packet from a registered dealer — not loose seed or seed saved from last year's fruit, which carries disease and grows unevenly.

Make shallow drills across the bed, about two finger-widths apart, and sow the seed thinly — it is small, so scatter it like a light pinch of salt, not in clumps.

Cover with only a light dusting of fine soil (about ½ cm) — barely more than the seed's own thickness. Tomato seed is tiny and cannot climb up from deep.

Water gently in the morning with a fine rose or a soft sprinkle, and keep the bed moist but never soggy — wet soil is what wakes up damping-off.

Look for the seedlings to break ground in about 8 days. If a patch topples and rots at the base → that is damping-off: thin out the crowding, cut back watering, and let the surface dry between waterings.

Start hardening off in the last 6-14 days before you plan to transplant, once the seedlings have 4-5 true leaves.

Cut back the water a little — let the surface dry more between waterings so the seedlings toughen up (but never let them wilt hard).

If you shaded the bed, take the shade off gradually so the seedlings get used to full sun.

Stop hardening and water the bed well about half a day (12 hours) before lifting, so the seedlings go to the field plump and a ball of soil holds together on their roots.

Do this in the 2 weeks before transplanting. Choose land that has not grown tomato, potato, pepper or eggplant for at least 2-3 seasons — better still, one rested under a cereal (maize, sorghum). Those crops share tomato's worst soil disease, bacterial wilt, which has no cure.

Clear old crop trash and weeds, then dig or plough the soil over at least a spade deep so roots can push down freely. On flat or heavy land, make raised beds or ridges so rain drains away — standing water rots roots and wakes up bacterial wilt.

Work in well-rotted compost or manure — dark, crumbly, no strong smell — to feed the soil and help it hold moisture evenly through the season. Never use fresh manure; it burns young roots and carries disease and weed seed.

If your soil is sour (acid) — past crops stayed pale and stunted, or a test reads below pH 5.5 — work in lime now. Tomato wants soil closer to neutral (pH 6.0-6.8), and lime also adds calcium, which helps fight blossom-end rot later.

Work the basal fertiliser into the bed just before transplanting — your recommendation gives the exact amount. This phosphorus-rich feed drives the strong early rooting the plant needs before it starts climbing.

Buy stocky, dark-green seedlings 15-25 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: no cupped, yellow-edged or crinkled leaves — a sign of the leaf-curl virus — and no wilting or spots. Reject the whole batch if many look sick.

Buy from a nursery that raises its seedlings under net or screen — those carry the fewest whitefly and the least virus.

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 cool, cloudy day — never in the hot midday sun, which wilts the seedling before it can root.

Water the nursery well beforehand and lift each seedling with a ball of soil on its roots, so you barely disturb them.

Set each seedling deep — right up to its seed-leaves (cotyledons). Bury a tall, leggy stem even deeper; tomato grows new roots all along the buried stem, giving a stronger plant.

Space the plants about two hand-spans apart along the row (≈40 cm) and leave 60-100 cm between rows, so you can walk, stake, prune and spray.

Firm the soil around each stem and water in at once with at least a cup per plant, so the roots meet damp soil with no air pockets.

When you transplant, keep a few spare seedlings back in the nursery for exactly this.

Walk the field 5-10 days after transplanting and mark every station where the seedling died or never took.

Replant each gap in the cool of evening with a spare, lifted with a ball of soil, and water it in just like the first plants.

Do it early — a plant put in two weeks late never catches up, and it shades or gets shaded by its bigger neighbours.

Walk the field in a large "W" every 3-4 days, checking plants at the four corners and the middle — not just along the path.

Cutworms: look for young plants cut clean off at ground level (worst in the morning). Scratch the soil nearby to find the fat, grey, curled caterpillar and squash it.

Bacterial wilt: watch for a plant that wilts in the heat of the day but stays green — no yellowing first. Cut a wilted stem low and stand it in clear water: milky threads streaming out means bacterial wilt — pull that plant out and remove it, and don't replant tomato there.

Whitefly: shake a plant and watch for a cloud of tiny white flies rising from under the leaves; check the leaf undersides. They are the carriers of the leaf-curl virus.

Leaf-curl virus (TYLCV): look for new leaves that are small, cupped upward, yellow at the edges and crinkled, on a stunted plant. There is no cure — pull and remove infected plants so whitefly can't carry it on to the rest.

Keep the topsoil steadily moist for the first two weeks — water every 2-3 days, more often in heat or on sandy soil that dries fast.

Water at the base of the plant, not over the leaves — wet leaves invite blight and rot.

Check with a finger: water when the top few centimetres are dry, but never leave the plant sitting in water.

Walk the "W" every 3-4 days and check the leaves top and bottom on plants across the whole field.

Tuta (tomato leafminer): look for pale, winding tunnels (mines) inside the leaf, like blister-trails, with tiny black droppings — hold a leaf up to the light to see the grub inside.

Early blight: look for brown spots with rings inside them, like a target, starting on the older, lower leaves, often ringed with a yellow halo.

Late blight: look for large, greasy grey-brown patches on leaves and stems, with white mould underneath in damp weather — it spreads fast and kills whole plants, so act at the very first sign.

Whitefly: keep checking the leaf undersides for the tiny white flies that carry virus.

Note what you find and where. If anything is over threshold → open the matching pest or disease guide and act now.

Put a strong stake beside each plant, or run overhead wires and drop a string down to each plant, while the plants are still young and upright.

Push each stake in on the opposite side to the roots, so you don't spear the root ball.

Make the first tie low on the stem, about 30 cm up — a hand-span and a half, using a soft strip of cloth or banana fibre in a loose figure-of-eight — snug to the stake, loose around the stem so it doesn't cut in as the stem thickens.

Plan to add a fresh tie every 20-30 cm as the plant climbs through the season.

Know your type first: staking (indeterminate) types grow taller all season and need pruning; bush (determinate) types stay short, set most fruit at once, and should not be heavily pruned.

On staking types, choose the 1-2 strongest stems to keep as your leaders.

Pinch out the side-shoots — the little shoots that sprout in the 'armpit' between the main stem and a leaf — while they are still small (5-10 cm), snapping them off with your fingers.

Do this every week, since new shoots keep coming — a short weekly walk keeps the job easy.

Don't over-strip the plant: leave enough leaf to shade the fruit, or the exposed fruit gets sunscald (a pale, scalded patch).

Apply the first nitrogen top-dress about 3 weeks after transplanting, when the plants are established and growing away strongly.

Band it in a line about a hand's width (≈10 cm) from the stems — roughly one bottle-cap per plant — never heaped against the stem, where it burns the plant.

Apply onto moist soil (after watering or light rain) and cover it or water it in, so it feeds the roots instead of gassing off into the air.

Lay a mulch of dry grass or straw around the plants to hold the moisture even and stop soil-borne disease splashing up onto the lower leaves.

Water every 3-4 days, aiming for even soil moisture — never let the plant wilt and then drown it.

Water at the base, under the mulch, keeping the leaves dry to starve the blights.

On sandy soils and in heat, water more often but with less each time — the goal is steady, not swinging.

Walk the "W" every 3-4 days, now checking the flowers and young fruit as well as the leaves.

Bollworm: look for round holes bored into green fruit and fat caterpillars — pick off and destroy any holed fruit and every caterpillar you find.

Tuta: look for mines in the leaves and pin-holes boring into the small fruit near the stalk.

Red spider mite: look for leaves going pale, stippled and dusty-silver, with fine webbing underneath — worst in hot, dry, dusty spells; check the lower leaves first.

Watch the weather and the flowers: on very hot days, check whether flowers are drying and dropping without setting fruit. If flowers are dropping instead of setting → the cause is almost always heat or a dry spell: even out the water, top up the mulch to cool the soil, and shade or wait out the worst heat.

Keep the soil evenly moist right through flowering and fruit set — do not let it dry out more than about four-tenths (40%) of the way down before you water again.

Water every 2-3 days, under the mulch, at the base of the plant.

Never let the plant wilt at this stage, even for a single day — one hard dry spell now drops flowers and starts blossom-end rot.

If you can only water well at one stage in the whole season, make it this one.

Apply boron just before the flowers open (your recommendation gives the exact timing and amount).

Mix the exact recommended amount into water — measure it, do not guess — and spray it as a fine mist over the leaves.

Spray in the cool of early morning or evening, with the wind behind you, covering your skin, nose and eyes.

Never apply more than the recommended rate. Extra boron poisons the plant and makes blossom-end rot worse by locking out the calcium the fruit needs.

Walk the "W" every 3-4 days, checking the fruit closely now — not just the leaves.

Tuta on fruit: look for pin-holes and tunnels boring into the fruit, usually near the stalk, with dark droppings — pick and destroy holed fruit every pass.

Late blight on fruit: look for hard, greasy, brown-marbled patches on green fruit, and greasy grey patches on leaves and stems, spreading fast in cool, wet weather.

Sunscald: look for pale, papery, sunken patches on the side of the fruit facing the sun — a sign you have pruned or de-leafed too hard and left fruit exposed.

Remove and destroy any mined, rotten or fallen fruit on every pass — it breaks the Tuta and fruit-fly cycle.

Start the potassium top-dress as the first fruits are swelling, and repeat every 10-14 days through the fill.

Band it about a hand's width from the stems — roughly one bottle-cap per plant — onto moist soil, and water it in.

Keep it off the leaves, the stem and the fruit.

Water every 2-3 days to keep the soil evenly moist — the same steady rhythm, right through fruit fill.

Keep the mulch topped up to hold moisture even and cushion the swings between waterings.

Never let the plant dry out and then flood it — a big drink after a dry spell is what cracks the fruit.

Water at the base, keeping the leaves and fruit dry to starve late blight.

As the trusses get heavy, tie them up or prop the stem so the weight doesn't snap or bend it down to the ground.

Strip off the lowest, oldest and any diseased leaves — especially those touching the soil — to open airflow and stop soil-borne blight splashing up.

Keep enough upper canopy to shade the fruit — do not strip the plant bare, or the exposed fruit gets sunscald.

Do this when the plants are dry, and carry any diseased leaves out of the field to destroy — don't drop them between the rows.

Match the colour to the market: pick at mature-green or 'breaker' (the first blush of colour) for fruit that must travel far — it is firmest and rides best; pick pink to red-ripe for local sale or eating, where taste matters most.

Pick often — every 1-3 days, especially in the heat, so the fruit doesn't over-ripen on the plant.

Twist the fruit gently to snap it off at the knuckle (the natural joint on the stalk), and keep the green cap (calyx) on — it holds and sells better.

Lay the fruit gently into a crate — never toss or heap it. A bruise you can't see now becomes a rotten fruit by market day.

Remove and destroy any holed, mined or fallen fruit on every pass — this breaks the Tuta and fruit-fly cycle for the passes still to come.

Get the field heat out fast: since you picked in the cool morning, move the fruit straight into the shade and keep it there — never leave crates standing in the sun.

Pack in ventilated crates, not sacks or deep baskets — air must move through, and the stacked weight must not crush the fruit.

Grade the fruit by size and colour, and cull out any cracked, holed, rotting or sunscalded fruit — one rotting fruit spreads rot to its neighbours.

Keep it cool but not cold: hold mature-green fruit around 12-15 °C and ripe fruit around 10-12 °C; never chill below about 10 °C, or the fruit gets cold-damaged, goes pitted, and never ripens properly.