Between a dry seed and a plant ready to produce, there are about ten days when everything is decided, then a few moves that change everything. By the end of this step, you'll know how to sow at the right millimetre, germinate at the right temperature, come out of the dome without losses, give light that builds instead of stretching, clone a plant by taking cuttings, and move your plants from the propagator to the tent without a jolt.
Sowing step by step: from seed to emergence
A seed is an embryo and its supplies. It needs nothing but warmth, constant moisture and darkness: no light, no fertiliser, no rich compost. Your job comes down to giving it a stable bed and then leaving it alone.
The moves, in order. Fill your pots with a light, low-nutrient seed-starting substrate, gently firmed with your fingertips. Moisten it before sowing; it should be damp like a wrung-out sponge, never soaked. Place the seed at two or three times its own diameter deep (rule of thumb), cover without compacting, mist the surface, label, and close the lid. Then be patient: tomato emerges in 5 to 8 days when the substrate stays between 24 and 29 °C, and every degree lower stretches the wait.
Choose fresh, lightly fertilised seed compost and clean containers: that's the number one prevention against damping off, the fungal disease that pinches the stem at soil level and lays the seedling flat overnight, with no cure. Its triggers are always the same: waterlogged substrate, stagnant air, old compost or garden soil. Water from below and let it drain, ventilate as soon as they emerge, and immediately remove any affected plant along with its root ball. On nutrition, the seed feeds itself until the first true leaves; after that, a solution diluted to 50 % of the normal dose, once a week (rule of thumb), for as long as the plant stays in the propagator. The full dose and the rhythm after potting on are detailed in step 4.
🌶️ Chillies ask for more patience than tomatoes: reckon on about 8 days to emerge at 25 to 30 °C, 12 days around 20 °C, and up to 25 days at 15 °C (rule of thumb). A chilli sowing that takes its time in the cold isn't a failed sowing: it's just waiting for warmth.
