How to Grow Tomatoes — Any Climate
How to grow tomatoes anywhere in the world, without a calendar: wait for a soil temperature, not a date. Tomatoes are heat-loving, frost-tender. Start indoors 6-8 weeks before your last frost date; transplant once soil exceeds 15°C (60°F) and night temperatures reliably hold above 10°C (50°F). Give them full sun (6-8h+), space them 45-60 cm (18-24 in) apart, and allow 60-90 days from transplant. These thresholds hold in any climate and either hemisphere.
When to plant tomatoes — the conditions to wait for
There is no universal date for tomatoes, because the same calendar month means completely different things at different latitudes and in opposite hemispheres. What does not change is the set of conditions the plant responds to.
| Condition | What this crop needs |
|---|---|
| Temperature class | Heat-loving, frost-tender |
| When conditions are right | Start indoors 6-8 weeks before your last frost date; transplant once soil exceeds 15°C (60°F) and night temperatures reliably hold above 10°C (50°F) |
| Light | Full sun (6-8h+) |
| Spacing | 45-60 cm (18-24 in) apart |
| Germination time | 6-14 days |
| Days to maturity | 60-90 days from transplant |
Observe, measure, decide
- Observe. Watch what your own garden does, not what a calendar says. When does standing water disappear in spring? Where does frost linger longest? Which corner warms first? A season of notes beats any regional average.
- Measure. Two instruments settle almost every timing question: a soil thermometer pushed 5-10cm (2-4in) into the bed at the same time each morning, and your own records of first and last frost. Soil temperature is the number that actually governs germination.
- Decide. Match the measurement to the crop's temperature class, then count backwards from your frost date using days-to-maturity. If the arithmetic does not fit your season, change the cultivar or the crop — not the date.
💡 The one instrument worth owning
A soil thermometer pushed 5-10 cm (2-4 in) into the bed, read at the same time each morning, answers more timing questions than any calendar. Soil temperature — not air temperature — governs whether seed germinates or rots.
Soil and site
Well-drained, fertile soil, pH 6.0-6.8. Amend with compost before planting; raised beds help in poor native soil.
Watering
Deep, even watering prevents blossom-end rot, a calcium-transport problem caused by inconsistent moisture, not a soil deficiency (see Part 3). Water at the base to keep foliage dry.
Spacing and layout
Space tomatoes 45-60 cm (18-24 in) apart. Crowding is the most common cause of disappointing yields — plants compete for light and water, and poor airflow between them raises disease pressure sharply.
Companion planting
Marigold (strong evidence — root exudates suppress root-knot nematodes when block-planted first); basil (moderate evidence).
Common problems
Blossom-end rot, early and late blight in humid conditions, aphids. Deep, consistent watering and a 3-4 year rotation away from other Solanaceae are the most effective non-chemical defences.
Turn growing tomatoes into a written plan. The Global Vegetable Garden Planner (printable PDF) has the soil-temperature reference, crop rotation planner, sowing log and harvest tracker — 73 pages, no calendar required.
Frequently Asked Questions
When should I plant tomatoes?
Wait for conditions rather than a date. Start indoors 6-8 weeks before your last frost date; transplant once soil exceeds 15°C (60°F) and night temperatures reliably hold above 10°C (50°F). This works identically in either hemisphere.
What temperature do tomatoes need?
They are a heat-loving, frost-tender crop. Germination takes 6-14 days once conditions are right.
How far apart should tomatoes be planted?
Space them 45-60 cm (18-24 in) apart.
What usually goes wrong with tomatoes?
Blossom-end rot, early and late blight in humid conditions, aphids. Deep, consistent watering and a 3-4 year rotation away from other Solanaceae are the most effective non-chemical defences.
Last updated 25 August 2026
Tools That Help With This Crop
Use these links when the guide moves from reading into sowing, planting, watering, and keeping the crop healthy.
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.