When to plant chilli seeds – you'll need to get sowing ASAP for a spicy harvest

Chillies are one of my favourite things to grow – they’re fun, and you can start them indoors much earlier than other vegetables. I thought I’d take a look at exactly when to plant chilli seeds to ensure a successful crop this year.

Learning how to grow chillies is pretty straightforward, and the good news is that there’s a wide window for sowing. You can get started as early as January, even – but it depends on when you want to harvest them, and on the variety (more specifically, how spicy it is).

I checked in with the experts to help you decide exactly when to plant chilli seeds this year.

What you'll need

• Chilli seeds – Chilli Pepper 'Fresco Mix' F1 from Thompson & Morgan was the first variety I tried and had success with.
• A heated propagator like the EarlyGrow Heated Electric Medium Propagator from Amazon.
• Some seed compost – my chillies thrive when I use Dalefoot Composts Peat Free Wool Compost for Seeds, available at Sarah Raven.

One of the perks of growing chillies is that they can be sown much earlier than other crops – especially if you’re hoping to grow hot varieties. You’ll need the right equipment, though.

‘For the tallest varieties and the highest yields of hot, fully-ripened chillies, sow your chilli seeds in January or February,’ advises Annelise Brilli, horticultural expert at Thompson & Morgan. ‘However, you will need a heated propagator and a greenhouse to provide adequate warmth and light.’

If you’re hoping to grow fruits that rank higher on the Scoville scale and want to get started before the warmer weather arrives, a heated propagator might be worth it.

Annelise Brilli

Annelise Brilli is the horticultural copywriter for Thompson & Morgan. Annelise caught the gardening bug from her mother, whose tiny backyard was crammed with a huge collection of plants. She is passionate about sustainable gardening and has developed her own wildlife-friendly garden which she has opened as part of Macmillan Coastal Garden Trail.

Generally, the spicier the variety, the early you should get started.

‘Hotter varieties of chillies will need a longer growing period if growing from seed,’ agrees Graham Smith MCIHort, horticultural expert at LBS Horticulture.

We’re in April already, though – so what does this mean if you’re yet to sow your chillies?

‘Chilli seeds can generally be sown indoors from late winter to mid-spring, as they usually need a long growing season, and an early start can lead to a better harvest,’ says Graham.

So, mid-spring sowings are still an option – and you can add chillies to your list of things to plant in April. ‘You can plant them from March without a propagator,’ Graham adds.

Smaller varieties are especially popular choices for spring sowing. ‘Choose a compact variety (like Chilli Pepper 'Cayannetta' F1) and sow the seeds on a warm windowsill in March and April,’ says Annelise from Thompson & Morgan.

FAQs

When can I put chilli seedlings outside?

With warmer weather on the way, you're probably wondering when it's safe to plant your chilli seedlings outside.

Well, you don't have to – and actually, they often fare better under cover.

'Chillies require plenty of warmth, so they perform best if grown in a greenhouse, conservatory or polytunnel,' explains Annelise from Thompson & Morgan.

If you don't have that kind of growing space available, you can keep them outside. I did, and I still managed to harvest fruits from my plant.

'For growing on a sunny patio in mild parts of the UK, select small varieties with milder fruit and move them outside around late May or early June after carefully hardening them off,' advises Annelise.

So, there we have it: you can plant chilli seeds from January onward if you want a successful crop – especially if you’re growing hotter varieties. If you haven’t sown them yet, though, you can still sow chillies on a warm windowsill this month.