Tomato (Solanum lycopersicum)

Month on the bottom, temperature up the side. The pale green background is what the plant can survive at all -- fatal above or below it, labelled directly on the chart where that applies to your zone. The coral band is its ideal range, and only fades in during the months this zone would actually have the crop in the ground -- reusing the exact same sowing/harvesting data as the calendar further down the page. The blue line is real monthly climate data (not a modelled estimate) for a representative rural/agricultural location in this zone -- a small farming town or agricultural research station rather than a major city, to avoid the warmer bias city weather stations have. For the actual verdict on how well this crop does in your zone, see the badge at the top of the page -- that's based on the site's own researched yield figures, not this chart. This chart shows the greenhouse variant's temperature comfort zone -- outdoor tomato is noticeably less forgiving outside it.

1. Start under cover. Sow seed under cover in late winter or early spring, earlier for greenhouse cordon varieties than for outdoor bush types -- tomato needs real warmth to germinate and establish.
2. Choose the right type for your setup. Bush (determinate) varieties are the more reliable choice outdoors; cordon (indeterminate) varieties give higher yields but need staking, side-shooting and the protection of a greenhouse or polytunnel in cooler zones.
3. Plant out once all frost risk has passed. Tomato has essentially no frost tolerance at any stage -- wait until night temperatures are reliably above about 10°C before planting out.
4. Keep watering even. Consistent moisture prevents blossom end rot and fruit splitting -- irregular watering, especially a dry spell followed by heavy rain, is the most common cause of both.
5. Harvest as fruit ripens. Pick tomatoes as they ripen through summer and early autumn -- a heavy glut is common, and freezing, drying or turning a surplus into passata is a practical way to bank it rather than let it go to waste.

Pick your zone under "Temperature Range by Month" above and this updates too. This calendar reflects the greenhouse/protected variant's wider window -- outdoor-only growers in cooler zones should treat the early and late edges of this window with real caution, and lean on the zone-fit badge above for the honest yield picture rather than the calendar alone.

Tomato is a low-calorie but genuinely high-yielding crop at about 180 kcal per kg. Subtropical and Mediterranean zones give the best yields here, and the gap between outdoor and greenhouse growing widens sharply in cooler zones.

Figures per plant, from the site's own crop database, taking whichever of outdoor or greenhouse yields higher in each zone. In Boreal and Alpine, only the greenhouse variant is viable at all, and even then only as "challenging."

Tomato varieties fill genuinely different niches -- fresh eating, sauce-making, or storage -- and vary hugely in flavour. All the varieties below are open-pollinated (OP), meaning seed saved from them breeds true and is worth keeping under this site's seed-saving approach; none are F1 hybrids.

Tomato is mostly self-pollinating with very low crossing risk between varieties -- one of the easiest and most forgiving seeds to save on this site.

Tomato isn't described as a storage crop in the site's own crop data -- it's grown to be picked as it ripens and eaten fresh, though a heavy glut is genuinely common with a productive plant.

For banking a surplus, tomato preserves well several ways: frozen whole for later cooking, dried (sun or low oven) for a concentrated, shelf-stable product, or cooked down into passata or sauce and canned or frozen -- all genuinely practical ways to carry a summer glut into winter.

Blight (a fungal disease thriving in damp, humid conditions) is the main risk for outdoor tomato in wet zones, capable of devastating a crop within days once established.

Choosing a blight-resistant variety is the single most effective input-free defence where this is a real risk -- far more reliable than trying to manage humidity around outdoor plants.

Watering at the base, not overhead, and good airflow between plants both reduce the damp-leaf conditions blight and other fungal problems need to take hold.

Crop rotation alongside potato matters here too, since they share the same family and some of the same soil-borne disease pressure -- avoid growing tomato where potato grew the previous year.