When to sow tomatoes?
- Botanical name
- Solanum lycopersicum
- Family
- Solanaceae
Tomatoes are sown indoors in March, 1 cm deep. They germinate in 8 to 10 days. They are harvested from July to October.
Tomatoes are annual plants. The edible part is the fruit.
Tomatoes through the year
- indoor sowing
- transplanting
- harvest
In short
Growing conditions
Companions in the bed
Companion planting is tradition and not an agronomic claim. What is recorded is which pairs sources recommend and which they advise against.
Borage at the edge of the bed is forage for the pollinators. It seeds itself on, so leave it the edge and not the middle.
Corn and tomato share a pest, and the corn takes the tomato's sun.
- “Cited” means the pair is named by one source or two.
- “Sources disagree” means one source recommends the pair and another advises against it.
Pests and diseases
Listed here is every problem for which the sources name this plant as a host. The problems are not listed in order of how common they are.
Aphids
pest- Signs
- Colonies of small aphids sit on the shoot tips and the underside of the leaves. The leaf curls and puckers, and sticky honeydew is left on everything below. The viruses they carry are more dangerous than the feeding itself.
- Prevention
- Go easy on nitrogen, because soft sappy growth is what aphids are looking for. Encourage the predators (ladybirds, lacewings, parasitic wasps). Use a reflective mulch, which puts them off settling, and a strong jet of water to knock the colony off the tips.
Blossom end rot
disorder- Signs
- At the blossom end of the fruit there is a watery, then dark, sunken and leathery patch. It is not a disease and does not pass from plant to plant, it is a sign that calcium never reached the fruit.
- Prevention
- Even moisture in the soil is the main measure: mulch and deep watering instead of a little and often. No excess nitrogen. Lime after a soil test, so that the calcium in the soil is available at all.
- What to do
- Remove the affected fruit. The next fruits come clean once the moisture steadies. A calcium spray gives temporary relief at best and does not replace watering.
Late blight
disease- Signs
- On the leaves and stems there are dark, watery blotches, spreading fast until the leaf browns and dies. On the underside of a blotch there is a white down. On the fruit there are firm, olive brown patches. In cold wet weather the plant collapses in a few days.
- Prevention
- Plant healthy stock and keep to the rotation. Give the plants a wider spacing and an airy site. Water under the leaves, never over the foliage. Remove diseased plants as they show and take them out of the garden, not onto the compost. Choose resistant varieties.
Slugs and snails
pest- Signs
- Holes appear in the middle of the leaf rather than along the edge, young plants are eaten down to the ground, and there are slimy trails in the morning. On low-growing fruit there are gnawed pits.
- Prevention
- Remove the hiding places beside the bed: boards, stones, dense weeds. Water in the morning and not in the evening, so that the night is dry. Spread a band of coarse sand or gravel around the bed. Cover young plants with fleece. Pick them off at night, which is still the most effective measure.
Keep track of your plants with Tendask
Log the task and set a reminder for the next one. Every plant keeps its own history, so there is nothing to guess at.
Related plants
The plants below are in the same botanical family (Solanaceae).
Sources about the plant: ASPCA Toxic and Non-Toxic Plants, Clemson Cooperative Extension, GBIF Backbone Taxonomy, KGZS, NC State Extension Plant Toolbox, Royal Horticultural Society, Semenarna Ljubljana, Utah State University Extension, Wikidata. Checked between 14 and 28 August 2026. The problem descriptions also draw on: EPPO Global Database, University of Maryland Extension, University of Wisconsin-Madison Division of Extension.