Loads of people pop their tomatoes in pots or containers on a sunny patio or in a greenhouse. They’ll grow well in the fertile compost, but there are a few things you can do for an even better crop.
Firstly, you need to give them plenty of space for their roots. You can happily grow three tomato plants in a grow bag, or a single tomato in a 20cm pot, but they will be much healthier, happier and more productive if they have a bit more space to put their roots out, so if you can, grow two plants to a grow bag or give a single plant a 30cm pot. It’ll make all the difference.
Our next piece of advice is to add a good handful of wormcast fertiliser to the soil as you plant each tomato (pop a handful in the hole before you plant). The nutrients in grow bags and compost are used up surprisingly fast, within 3-4 weeks usually. The wormcast fertiliser releases nutrients slowly so will keep your tomatoes well nourished right through until they’re ready to harvest.
The final trick is to ensure that the soil is kept consistently moist. You don’t want your tomato plants to go from very dry soil to very wet soil, as this causes both split fruits and ‘blossom end rot’ which will damage your crop. Pots are quick to dry out, so water them morning and night to keep them moist. Grow bags can be watered in the evenings as they won’t dry out as quickly. Use your own judgement here – if you see/feel that the soil is drying out you need to water more regularly, and if it’s getting too wet, don’t water it quite so often!