Chilli Seeds in Ireland

How to sow chilli seeds

Sow into fresh, moist seed compost in a small pot or module tray, cover with about 5mm, and firm gently. Water before sowing rather than after, so you are not washing the seed about.

Then give it heat from below. Chilli seed wants the compost held at 25 to 30C, and held is the word that matters: a windowsill at 24C in the afternoon and 11C at three in the morning will not do it. A heated propagator or a thermostatic heat mat is the one piece of kit that changes chilli growing here from unreliable to routine.

Germination takes seven to twenty-one days, and hotter varieties are usually at the slow end. Do not give up at two weeks.

The instant the first loop of stem appears, get the tray into light. From a January or February sowing that means under a grow light for 14 to 16 hours a day, positioned 20 to 30cm above the seedlings. Irish daylight at that time of year will not build a sturdy plant, and unlike a tomato, a stretched chilli seedling cannot be fixed by potting it deeper.

Prick out into 9cm pots at the first true leaves, keeping the plants somewhere around 20C afterwards. They can come off the bottom heat once they are up but they should not go anywhere cold.

Growing on in Irish conditions

Pot on into 2 litre pots as roots fill the 9cm ones, then into a 5 litre pot for a compact variety or 10 litres for a taller one, or into a greenhouse border.

Move plants to their final position in a greenhouse, polytunnel, porch or windowsill from late May. Do not plant into an open bed. Keep fleece to hand for cold nights in May and early June, because cool nights during flowering are the main reason an Irish chilli plant sets less fruit than it should.

Pinch out the growing tip at around 20cm to encourage branching, which produces more flowering points and a sturdier plant. Stake taller varieties once the fruit start to weigh the branches down.

Feed with a high potash tomato feed once the first fruit have set, and water evenly. Chillies want less water than tomatoes and dislike sitting wet, but a plant that dries out completely will drop its flowers.

On warm still days under glass, tap the stems or brush the open flowers with a fingertip. Chilli flowers are self fertile but need movement to shed pollen, and a closed Irish greenhouse in June has very little of it.

Harvesting

Fruit are usable green from July and ripe from August onwards, with the main flush through September and October under cover.

Cut fruit off with scissors or secateurs rather than pulling, because the brittle branches snap easily. Picking regularly makes the plant produce more, so take fruit as they colour rather than leaving a full plant to look impressive.

Green chillies are milder and taste more vegetal; the same fruit left to ripen fully is hotter and sweeter. Most of the heat sits in the white pith around the seeds rather than the seeds themselves, so removing the pith is what reduces the heat of a dish.

Thin walled varieties such as cayenne dry beautifully on a string in a warm room. Thick walled ones such as jalapeno do not dry well in Irish air and are better frozen whole, which works far better than it sounds, or pickled.

Overwintering for a second year

This is the single most useful trick for an Irish chilli grower. In late October, once cropping finishes, pick everything, cut the plant back to a framework of about 15cm of woody stem, and remove all the remaining leaves.

Keep the pot somewhere frost free and reasonably bright at roughly 10 to 15C, a spare bedroom windowsill or a heated porch rather than a cold greenhouse, and water only enough to stop the compost drying out completely, perhaps once every three weeks. The plant will look dead. That is expected.

In March, move it back into warmth and light, top dress with fresh compost and start watering and feeding again. New shoots come from the old wood within a few weeks, and because it starts as an established plant it flowers a month or more earlier and crops far more heavily than a first year plant. Some will not make it through, so keep two if you have the space.