Chilli 'Medusa'

Six steps to hotter chillies

Discover six tricks to help you grow the hottest chillies.

If you want to grow chillies with a bit of bite, there are plenty of tricks you can employ. Getting the right growing conditions is vital – the hotter the growing conditions, the hotter the chilli, which is why they grow well in hot parts of the world.


Matt Simpson of Simpson’s Seeds has grown some of the UK’s hottest chillies, named ‘Katie’ and ‘Lucy’ after his daughters. He’s employed some unusual tricks to increase the heat of his fruits.

He has discovered that by stressing plants – by damaging them, denying them food and water, subjecting them to extreme heat and even shouting at them – you cause the plant’s natural defences to kick in and make the chillies spicier in a bid to stop them being eaten by animals.

Here, Matt shares his tips to help you grow a super-hot chilli.

The hotter the growing conditions, the hotter the chilli.


Choose a hot variety

Bhut jolokia chilli pepper
‘Bhut Jolokia’ chilli pepper

There are hundreds of varieties of chillies, with differing heat levels. The very hottest varieties, such as ‘Bhut Jolokia’ are slow growing and need heat and humidity, so grow them indoors for a decent crop. Discover eight hot chillies to grow.


Start growing early

Sowing chilli seeds
Sowing chilli seeds

Even the easiest chillies need a long season to give plants plenty of time to grow, flower, fruit and ripen, and the hottest varieties need sowing as early as January. If you miss the boat, or want to give super-hot varieties a head start, grow from plug plants rather than seed.


Grow in the sunniest spot possible

Chilli pepper 'Paper Lantern'
Chilli pepper ‘Paper Lantern’

For the biggest crop, grow under cover, preferably in a greenhouse or polytunnel, but a bright, sunny kitchen windowsill is also good. If you have to grow them outside, give plants a warm, bright, sheltered spot.


Abuse plants

Removing the leaves from chillies
Removing the leaves from chillies

Matt Simpson is certain that stress increases the amount of capsaicin (the compound that produces the burning sensation) in the fruit and that the most effective way to do this is to abuse the plant by snapping off stems, leaves and fruit as soon as fruit starts to set. This mimics the damage caused by predating animals. It will result in a decreased yield but hotter chillies.


Feed sparingly or not at all

Diluting a plant feed for chillies
Diluting a plant feed for chillies

Not feeding plants is another way to put them under stress and increase capsaicin production. Giving chillies no fertiliser at all results in a weaker, stunted plant but chillies are hotter than they would be if fed. If you do feed, choose a specialist chilli feed, or use a tomato feed, to encourage the production of flowers, rather than leaves.


Keep them parched

Chilli pepper 'Pot Black'
Chilli pepper ‘Pot Black’

Allowing plants to dry out completely between watering will also make the fruits hotter. The downside of this is that plants will be weakened and your harvest will be smaller.

Boost your brain

Chillies contain high levels of the flavonoid apigenin, which helps neuron formation and strengthens the connections between brain cells.