Solanum lycopersicum
The crop most people start with, and still the one worth growing: a sun-warmed tomato tastes nothing like a shop one. Give it sun, steady water and something to climb, and a single plant can keep a kitchen in fruit from midsummer to frost.
Self-fertile — one plant sets fruit
Give it the sunniest spot you have; in shade the plants sprawl and the fruit ripens late and tastes flat.
Water deeply once or twice a week so the soil stays evenly moist; swinging between bone dry and soaked is what causes blossom end rot and split skins.
Any decent garden soil that drains well, with compost dug in before planting.
Mix compost in before planting, then feed lightly once the first fruits set; too much nitrogen gives a huge green plant and few tomatoes.
Put a stake or cage in at planting time and tie the stem to it as it grows; indeterminate types also need their side shoots pinched out weekly.
Pick when the fruit has taken its full colour all over but still feels firm; a ripe tomato comes away with a gentle twist.
Seeds sprout in about a week somewhere warm; they need warmth more than light until they are up.
Give the seedlings the brightest light you have and pot them on once the first true leaves appear.
The plant puts on leaf and stem fast; tie it in, pinch out side shoots, and keep the water steady.
Yellow flowers open in trusses; they set best in warm days and mild nights and drop in a heatwave.
Green fruit swells to full size, then stops growing and waits to change colour.
Pick when the fruit is fully coloured but still firm, every couple of days, right up to frost.
Stages affected: Vegetative · Flowering · Fruiting · Harvest window
A large green caterpillar, the larva of a hawk moth, that feeds on the leaves flowers and fruit of tomato and its relatives. The tobacco hornworm is an equally common close relative and is managed identically.
Stages affected: Vegetative · Flowering · Fruiting
The commonest leaf disease of garden tomatoes and a regular one on potatoes, and occasionally on peppers and aubergines. It works up from the soil in warm wet weather, stripping leaves from the bottom of the plant; on tomatoes that exposes the fruit to sunscald, on potatoes it shortens the season and trims the yield. Hungry or stressed plants suffer most.
Stages affected: Vegetative · Flowering · Fruiting
A leaf-spotting fungus that defoliates tomatoes from the bottom up. It often appears alongside early blight and is routinely mistaken for it, though the spots look quite different close up.
Stages affected: Fruiting
Not an infection but a disorder: a firm dark patch at the base of the fruit caused by calcium failing to reach the fruit as it grows, almost always because soil moisture swung between wet and dry. Tomato pepper aubergine and squash all get it.
Stages affected: Seedling · Vegetative · Flowering
Small soft-bodied sap-sucking insects that cluster on the softest new growth. They reproduce extremely fast in warm weather and are the main insect vector of plant viruses in the garden.
Stages affected: Vegetative · Fruiting
Mites under 1.3 mm that feed on the undersides of leaves and spin fine webbing. Populations explode in hot dusty dry conditions and after broad-spectrum sprays kill their predators.