12 Types of chillies

The heat in chillies is caused by the alkaloid capsaicin, which is measured in Scoville Heat Units. Most chilli peppers have around 6000 units, but hot varieties, such as the cultivar ‘Habanero’ have as many as 200,000 units.

Most chillies are easy to grow, but they need a long season to ensure the fruits ripen properly. Start them off in late winter – as early as January if you have a heated propagator – and then raise them in the greenhouse or on a sunny windowsill from April onwards. Some varieties can be grown outside in summer in the south of the UK, but good results are more likely if you raise them under cover.

We asked leading chilli grower Matt Simpson of Simpson's Seeds, to reveal his most popular chilli varieties, from the mildest to the very hottest. Each variety is listed with the number of Scoville Heat Units found in the chillies, plus Matt's rating based on how easy it is to grow.

Find out more about these 12 chilli varieties, below.

Chilli 'Alma Paprika'

Scoville Heat Units: 0

Growing difficulty: easy

Sweet and mild, but with a hint of black pepper, this richly flavoured and prolific Hungarian heirloom is dried to make paprika. The small plants are early-fruiting enough to try growing outdoors.

Chilli 'Erotico'

Scoville Heat Units: 1,000-5,000

Growing difficulty: easy

This is a cold-tolerant baccatum type of chilli, overwintering well in a cool greenhouse for a second year of harvests. The cheeky-looking fruits have a tangy, apple-like flavour.

Chilli 'Hungarian Black'

Scoville Heat Units: 5,000-10,000

Growing difficulty: fairly easy

A real looker, 'Hungarian Black' has gorgeous purple flowers and mild but richly flavoured fruits that ripen from red wine to dramatic black. It’s early to mature, too, so worth trying outdoors.

Chilli 'Aji Wrecking Ball'

Scoville Heat Units: 10,000-50,000

Growing difficulty: fairly easy

'Aji Wrecking Ball' bears lots of crunchy, fleshy fruits with a nutty, savoury flavour. The tall plants can survive winter in a cool greenhouse, so you’ll get a second year of even better harvests.

Chilli 'Thai Dragon'

Scoville Heat Units: 50,000-100,000

Growing difficulty: a little demanding

'Thai Dragon' is a small, ornamental variety with upward-pointing, thin-skinned green fruits, which ripen to red. Beware, though – after an initial sweetness they deliver a fiery kick.

Chilli 'Jamaican Hot'

Scoville Heat Units: 100,000-200,000

Growing difficulty: a little demanding

One of the fiercer Caribbean chillies, 'Jamaican Hot' bears generous crops of thin-skinned fruits. There are yellow and chocolate versions, but the hottest ripen to scarlet, with a dry, spicy flavour.

Chilli 'Yellow Scorpion'

Scoville Heat Units: 100,000-200,000

Growing difficulty: a little demanding

Allow plenty of room for this large-fruited Caribbean variety as plants reach over 1m tall. It’s sweeter and slightly less hot than most Scorpion chillies, though still has a quite a kick.

Chilli 'Zimbabwe Bird'

Scoville Heat Units: 200,000-350,000

Growing difficulty: fairly easy

'Zimbabwe Bird' is a small chilli that thrives on sunny windowsills, producing hundreds of bullet-like, blisteringly hot peppers. As a houseplant, it lasts several years, getting more prolific by the season.

Chilli 'Fruit Burst'

Scoville Heat Units: 300,000-400,000

Growing difficulty: a little demanding

This British-bred habanero laden with fruits that hang below the foliage like apples. Chillies are extremely hot, combined with a rich fruit salad aroma make this a favourite in hot chilli sauces.

Chilli 'Paper Lantern'

Scoville Heat Units: 350,000-400,000

Growing difficulty: fairly easy

This is a great super-hot chilli for beginner chilli growers, as this tall habanero ripens earlier than most, with more reliable results. Bears a heavy crop of 7cm-long fruits with a smoky, savoury flavour.

Chilli 'Black Naga'

Scoville Heat Units: 700,000-800,000

Growing difficulty: a little demanding

Bangladeshi variety 'Black Naga' bears large, thick-skinned chillies that need a long, hot summer to darken to full super-hot punch – occasionally hitting one million Scoville Heat Units. Cooking brings out a fruity flavour.

Chilli 'Naga Morich'

Scoville Heat Units: 1,000,000-1,500,000

Growing difficulty: a challenge

Handle with care: 'Naga Morich' is known as the serpent chilli. It’s a favourite with Bangladeshi chefs for its fruity, almost pineapple flavour but it has an extremely fiery bite.