Sweet Peppers & Chillies

Sweet peppers and chillies are both members of the same species, Capsicum Annum (some less common chillies come from other capsicum species).

Pepper flowers are self- pollinating, and will set fruit without any insect activity. However, they will also cross readily, and sweet peppers will happily cross with chillies. You need to isolate your plants by around 150 feet (50 metres) from any other peppers or chillies growing nearby. Even if you are only growing one variety, be careful about other varieties growing in adjacent gardens or allotments.

If you want to grow several varieties, or if your near neighbours are also growing peppers, you could consider making an isolation cage to cover 3 or 4 plants. This is easy to do, and costs very little, especially if you can get hold of some old net curtain material. You can put a cage up over plants grown in pots, grow-bags or directly in the ground.

To save the seed, take peppers on your isolated plants which have ripened fully to their final colour (usually yellow or red). Cut the peppers open carefully, and rub the seeds gently off of the 'core' onto a plate. Wear rubber gloves to deseed chillies, as the chilli oil sticks to your fingers and is very hard to wash off. Dry the seeds in a warm but not hot place until they snap rather than bending. More information on seed drying can be found under our section ‘Seed Cleaning and Seed Drying’ on our website.

Making an isolation cage

To make a simple isolation cage ideal for peppers or aubergines, you need some cheap nylon fly-screen 5 times as long as it is wide, four canes or thin stakes, and some string and garden wire. Alternatively, you can use old net curtains or other netting small enough to exclude insects. A piece of screen 1m by 5m will give a cage large enough to cover 3 or 4 plants.

Cut a square piece of screen 1m x 1m to make the top of the cage, and then fold the remaining strip of fly-screen round and sew its ends together. The resulting band will be the sides of the cage. Then sew the top to the sides, making a cube of fly-screen with the bottom missing.

To put up the cage over your plants, hammer the four canes into the ground in a square a little smaller than the cage top, so that they stick up a little less than the height of the cage. Twist a short piece of wire tightly round the top of each cane, and then run string in a square around the tops of the canes, supported by the wires to stop it slipping. Run a second piece of string around the stakes lower down to stop the sides of the cage blowing in against the plants. Then slip the cage over your plants, and weigh it down with earth or rocks.