| Annual or perennial | Annual (tender perennial grown as annual) |
| Difficulty | Moderate – needs warmth and attention |
| Height | 50cm-2m+ depending on variety |
| Spacing | 45-60cm (bush); 60-90cm (cordon) |
| Harvest window | July to October |
Tomatoes are the great obsession of the kitchen garden – and for good reason. A homegrown tomato, warm from the plant in August, tastes nothing like anything you can buy. They need care and warmth but deliver more than almost any other vegetable in return.
Which variety to grow
The choice is enormous. For Alsace’s relatively short hot season: cherry types (Sungold, Gardener’s Delight) ripen fastest and most reliably. Cordon (indeterminate) types like San Marzano or Marmande need a longer season but are worth it. For beginners, start with cherry tomatoes – they are faster, more forgiving, and almost always productive. Avoid beefsteak types in their first year unless you have a greenhouse or very sheltered spot.
When to plant
Sow seeds indoors in late March or April at 18-20 degrees minimum. Transplant to larger pots as they grow. Do not plant outside until after the last frost and nights are reliably above 10 degrees – late May to mid-June in Alsace. Harden off seedlings outdoors for a week before planting out.
How many to grow
Four to six cordon plants or eight to ten cherry plants feeds a family well through summer. Tomatoes are prolific once the season gets going – resist planting too many unless you plan to make sauce and preserve.
Conditions it needs
- Sunlight: Full sun – minimum 6-8 hours per day. More sun means more fruit and better flavour.
- Soil pH: 6.0-6.8
- Soil type: Rich, moisture-retentive but well-draining. Dig in plenty of compost before planting.
- Warmth: Essential. Tomatoes will stop setting fruit if nights drop below 10 degrees.
Container growing
Tomatoes grow very well in large containers (minimum 30-40 litres). Use rich tomato compost and water every day in hot weather – containers dry out quickly. Grow bags work but large individual pots are better. Cherry tomatoes in hanging baskets are a real option for a balcony.
How to care for it
Cordon (tall, indeterminate) tomatoes need regular side-shooting: pinch out the shoots that appear in the angle between the stem and leaves. Tie to a stake as they grow. Stop the plant (pinch out the top) in August to encourage remaining fruit to ripen before the season ends. Water consistently and at the base – irregular watering causes blossom end rot and splitting. Feed weekly with a high-potash tomato fertiliser once the first flowers appear.
Propagation
Grow from seed each year. To save seed from a favourite variety, scoop the gel and seeds from a very ripe fruit, ferment in water for 3-4 days, rinse, dry thoroughly, and store in a cool dry place. Only works reliably with open-pollinated (non-hybrid) varieties.
Watch out
Tomato blight (Phytophthora infestans) spreads fast in wet summers and can wipe out an entire crop in days. The symptoms – brown patches on leaves spreading to stems and fruit – are unmistakeable. Remove affected plants immediately, do not compost them. Grow blight-resistant varieties (Crimson Crush, Koralik) if your summers are wet. Blight-resistant varieties are the single best decision a beginner can make in Alsace.
Companion planting
Basil is the classic companion – said to improve flavour and deter aphids. Marigolds (Tagetes) deter whitefly and nematodes. Chives help with aphids. Avoid planting near fennel or brassicas.
Problems to watch for
- Blight: The main risk. Brown patches on leaves and fruit. Remove and destroy immediately.
- Blossom end rot: Black leathery patch on the base of fruit – caused by calcium deficiency from irregular watering. Water consistently.
- Whitefly: Check leaf undersides. Yellow sticky traps help. Encourage beneficial insects.
- Splitting: Caused by irregular watering – consistent moisture prevents it.
When and how to harvest
Harvest when fully coloured and slightly yielding to gentle pressure. Cherry tomatoes are best picked when they come away from the vine without resistance. Don’t wait for every tomato to ripen before picking – frequent harvesting encourages the plant to produce more. In September, if the season is ending, bring green tomatoes indoors to ripen in a warm place.
How to store
- Fresh: Never refrigerate ripe tomatoes – cold destroys their flavour. Store at room temperature.
- Sauce: Blitz and freeze in portions – the best way to preserve a glut.
- Dried: Halve small tomatoes, add salt and olive oil, dry slowly in the oven at 100 degrees for 4-6 hours.
- Passata: Cook down with garlic and herbs, blend, sieve, and freeze in jars.
In the kitchen
Savory
Caprese salad (with fresh basil and mozzarella), bruschetta, pasta sauces, pizza, ratatouille, shakshuka, roasted tomato soup, tomato tarts, stuffed tomatoes, salmorejo, panzanella. Tomatoes are the foundation of half the world’s cuisines – the quality of homegrown varieties makes every dish better.
Sweet
Tomato jam is a revelation – sweet, sharp, and complex. Green tomato tarte tatin and green tomato chutney are excellent ways to use the end-of-season crop.
Drinks
Fresh tomato juice with a pinch of salt and black pepper. Tomato and herb agua fresca. Gazpacho blurs the line between drink and soup.