Some like it hot - jalapeno and Padron peppers

Growing chilli peppers is addictive. They are so easy to raise and the rewards - a bountiful crop of glossy ripe peppers - so delicious that they are a must-have in the Secret Garden each year.

This year our two favourite varieties are the Spanish Pimiento de Padron, and the American japaleno. Of course, all chilli peppers are American in origin, as they were one of the plants brought back to Europe by the Spanish explorers in the early 1500s - it was Franciscan monks who brought the first pepper seeds to the Padron region of Galicia in north-west Spain, from where the Padron pepper was cultivated. These are served as tapas or pintxos dishes throughout northern Spain, sauteed in olive oil and sprinkled with salt, and eating them is something of a gamble. Most Padron peppers are mild, fruity and delicious, but a minority are hot, and it's impossible to tell which is which just by looking at them. You have to risk all by biting into them.

According to the Spanish phrase, "unos pican y otros no" ("some are hot and others not"). In practice it can be anything from one in 5 hotties to one in 15. Homegrown Padrons always seem to include more fiery ones than shop-bought, and the longer they stay on the plant, the more likely they are to be hot. I think.

Jalapeno peppers originate from Mexico and are a moderately hot chilli. They're picked and eaten when still a beautiful dark racing green colour and the slim conical fruits are smooth and glossy. Jalapenos are the variety of chilli which are smoked and dried to make chipotle; the fruits which are to be treated in this way will be left on the plant to ripen to a deep red colour before picking.

Chillies proved immediately popular not only in Europe but also in India and the Far East where they were taken to by Spanish and Portuguese traders. It's hard to imagine Indian and other Asian cuisines without chillies now, but before 1498, when the Portuguese explorer Vasco de Gama took the first chillies to India, they were unknown.

We are not terribly interested in growing record-breakingly hot chillies, preferring chillies that balance heat with flavour. Down at the lower end of the Scoville scale there are plenty of chilli varieties to give you plenty of kick, but also a more complex flavour behind the fire.

The Scoville scale measures the heat of chillies. It refers to the number of times that chilli extract can be dissolved in sugar water before the chilli heat can no longer be detected by the palate. It’s an imprecise scale because it relies on human taste buds, but useful in general terms, or to act as a warning if you can’t take too much chilli heat.

A sweet pepper has a Scoville rating of zero – no heat at all. The mild Padron peppers also score zero and the hotter ones up to 2,500. Jalapenos will come in at anywhere between 2,500 and 5,000 units. The hottest chillies were traditionally habaneros, at between 350,000-500,000 units, but in the last 10-20 years interest in cultivating ever-hotter chillies led to the bhut jolokia pepper grown at New Mexico State University in February 2007 clocking up over a million Scoville units. That’s more than twice as hot as the habaneros. The current record holder is the Trinidad Moruga Scorpion, which rated just over 2 million units, again at New Mexico State University – where they have a chilli pepper institute. It’s difficult to imagine just how hot that can be, but if I tell you that the testers reported that the chillies, when ground, were burning holes in their latex gloves, you get some idea. 

Chillies can be grown in the UK indoors, outside, in pots, growbags or in the open ground. Padron peppers are particularly good in our climate as they are adapted to the mild, damp climate from generations grown on the edge of the Atlantic in Spain. 

We sow our chilli seeds indoors in February, in small pots of ordinary multi-purpose compost. and then place them on a warm sunny windowsill to germinate, which takes about a week to ten days. Keep them in the pots until after the last frosts - around the end of April here in London, although we kept them indoors this year for longer than usual because of the cold. 

Then they can be planted out in a sunny, sheltered spot. We grow ours in large pots, three chilli plants to a 30cm tub, again filled with multi-purpose compost. After that, they can more or less be left to get on with growing themselves. They are relatively pest-free, although you should check for aphids every so often and wipe them off the leaves before they take a hold.

Flowers should start appearing in early July; the plants are self-fertile, and will reliably set fruit. They'll need watering once a week or so unless the weather is very rainy, and when the fruits start forming in July/August, we'll give them some tomato feed or seaweed extract a couple of times when watering. If the plants get very tall - some varieties will grow up to around 1.5m - they may well need staking, although our japalenos and Padrons have been quite happy so far this year without support.

The Padron peppers have been ready for harvest since the end of July and are best picked when around 5-6cm long - unless you like to find more hot than mild ones in your tapas.

Jalapenos need a longer season and will ripen a little later. We picked our first mature jalapenos this weekend and it looks like we'll have 2-3 a week from now on until the end of October or whenever we get our first frost.

Suppliers: Pimientos de Padron available from Franchi Seeds of Italy, Victoriana Nursery Gardens, and Nicky's Seeds, among others.
Jalapeno chillies available from Franchi Seeds of Italy, Real Seeds, Nicky's Seeds, Victoriana Nursery Gardens, and others.