Starting tomatoes: from seed to a strong young plant

Anyone who wants to harvest their own tomatoes starts on the windowsill in late winter. Raising them is not rocket science – what matters is enough light, the right temperature and a little patience. The effort is rewarded with varieties that are hard to find in shops, and with plants that are used to your own garden from day one.

The right time

Sowing too early is the most common beginner’s mistake. In January there is not enough daylight, and the seedlings shoot up thin and pale. The ideal time is mid-February to the end of March – then the plants are exactly the right size for planting out in mid-May.

Sowing step by step

1. Fill a seed tray with low-nutrient seed compost and press down lightly
2. Place seeds 2 cm apart and cover with 0.5 cm of compost
3. Moisten with a spray bottle, cover with a lid or film
4. Place at 20–24 °C; air briefly every day
5. After germination remove the lid and move somewhere cooler but very bright

Pricking out and hardening off

As soon as the first true leaves appear, the seedlings are moved into individual pots – deeper than before, as new roots form on the stem. From early May the pots go outside to a sheltered spot during the day so the plants get used to sun and wind.

Tomatoes only move outside for good after the last frost in mid-May. A single cold night below 5 °C can set growth back by weeks.

No time for seed starting?

Grafted young plants are the shortcut: they grow on a robust rootstock, resist soil-borne diseases better and bear considerably more. The tomato plant “Harzfeuer” arrives strongly pre-grown from mid-April.