It is very common for plants like tomatoes, chillies or even eggplants not to fruit. Equally, plants like sweet peas and annuals may not flower. Why??
Well, if the plants get less than 7 hours of sunlight each day, lack of light could be the answer.
But the most common cause is incorrect or over fertilising. So:
1. Stop fertilising with whatever you have been using and in a few weeks all should be fine.
2. To hurry things along you can buy special flower and fruit promoting fertilisers such as Bloom Booster or Better Bloom.
3. The most savage of all is to buy some potash from the plant shop. Use this carefully – exactly as per the instructions.
Hopefully in a few weeks from now your garden will be full of flowers and fruit.