Scoville scale helps distinguish cool customers from hot stuff

Medina chilli peppers.
Medina chilli peppers.

Gardeners who appreciate red hot chilli peppers – the vegetable, not the band – have had good reason to be confused over the level of heat different varieties contain.

Although the Scoville scale, which measures their hotness in Scoville heat units (SHU), has been in existence for a century, it has never meant much to the average gardener. But that is all about to change.

Thompson and Morgan has launched a range of chilli seeds in packets which carry a heat rating, giving a clear indication of what you are buying.

A simple pepper meter diagram on each packet indicates a number from nought to 10. Zero represents cool and sweet, six equals hot and 10 explosive.

Using this simplified scale, the Prairie Fire I grew last year would be classed as very hot and score eight.

If you’re wishing to experience explosiveness, you need to buy the varieties Naga Jolokia, Dorset Naga or Bhut Jolokia, which can be saved over winter and grown as a perennial under cover.

For chilli success, sow the seeds early, from January to March.

Offer generous warmth for germination and throughout their growth.

Allow the seedlings to grow a little before pricking out.

These are tropical plants and perform best in a higher temperature band, but this comes with a problem – attracting aphids.

That problem can be overcome by spraying water over and under the leaves daily at the height of summer.

Ensure you don’t neglect their watering and feeding by growing them alongside tomatoes in the greenhouse.

Pick ripe fruits regularly to encourage more.

Most importantly, having grown many more than you can ever consume, advise the lady of the house to use explosive varieties sparingly in the kitchen.

The smallest piece of Bhut Jolokia will suffice.