Please note: this list assumes you already have a plant. It does not cover growing the plants from seed. That’s a whole other matter (check our website for details on this), and instead, we’re starting at the point where you’ve already got young plants ready for transplanting and growing on.
• Use a south facing window. The south side of British homes get the most sunlight, and this is where the plants should be grown. East and west facing windows might do, but the plants will struggle. If you have the time and discipline, you could move plants around the house to follow the sun and get more light on them. Another trick is to put a mirror or some reflective material (available from hydroponic shops) behind the plants to shine the light back on them. But whatever you do, forget about using north facing windows – you’re simply wasting your time putting plants there.
• Choose short, compact varieties that are adapted to small pots. Smaller varieties grown in small pots will fit on a window sill without falling over.
• Grow only pungent varieties. However much you try, yields of fruit will be lower from plants grown on a window sill compared to those in a conservatory, tunnel or greenhouse. To compensate for lower yields, choose a variety that produces fruit with high heat levels – you will at least make something back.
• Do not over water or excessively fertilise. Because of lower light levels, plants grown on a window sill need to be watered and fertilised less often than those in a greenhouse or tunnel. Add water only when the compost begins to dry out, and give a liquid feed no more than once every three or four weeks.
• Place the pots in a plate or dish. No matter how careful you are with watering, some of the water will inevitably escape through the hole in the bottom of the pot. Putting the pots in a dish or plate will catch the water and prevent it from spreading over the window sill and making a mess of things.
• Control aphids. Aphids or greenflies will, at some point, attack your chilli plants. To bring them under control, wash them off under a stream of water, or spray the plants with an innocuous pesticide that won’t poison you or members of your family.
• Shake the plants or hand-pollinate the flowers. In the still conditions of the house, flowers may not pollinate and set fruit. Shaking the plants daily or hand pollinating the just-opened flowers with a small paintbrush may help, though be warned – low light levels might cause flowers to drop, in which case there is nothing you can do except expose the plants to more light.”