11:13 - 29 March 2010
Most gardeners that own a greenhouse grow tomatoes. That’s quite surprising when you consider that they are not the simplest or easiest crop to grow, but not surprising when you realise that nothing surpasses the flavour of home grown tomatoes. Sumptuous summer salads and the thought of warm, tasty tomatoes is simply irresistible. A plant draped in trusses of tiny cherry sized tomatoes is better than an afternoon in the sweet shop and undeniably better for you too. Plus of course if you grow lots of tomatoes to make your own chutneys, soups and other culinary delights, it’s tastier, healthier and more cost effective to grow your own.
The thing about tomatoes is they do need some tender loving care, so if you are short of time or starting out in gardening they may not be the right crop for you. Having said that you ought to have a go, but you’ll probably better off cheating by buying ready grown plants from the garden centre now or in April. This leapfrogs you ahead of anyone who has yet to sow his or her tomato seed, and avoids the need for heating the greenhouse early in the season. But you will need to keep them within the protected environment of the greenhouse until the last frost has passed and they need plenty of water during the growing season.
Sow from seed
If you prefer to grow from seed there are literally hundreds of varieties to choose from and it is more cost effective. You can sow outdoor varieties in March and April for a summer crop. Greenhouse tomato varieties can be sown as early as January but if you haven’t done so it is not too late to sow them now (March/April).
For the best results sow two seeds to a small module filled with a top quality seed compost. Label well and place into a heated propagator at 60-65F. Check daily and water sparingly when required. When the seedlings emerge after five to 10 days, move them into a warm (60-65F), light place to develop.
If both seeds in one module germinate then remove the weaker one and discard allowing the stronger seedling to grow in the module uninhibited. As soon as the roots of the tomato plant can be seen pushing out the drainage holes at the base of the module it is time to pot them up into small (7.5) cm pots. Use a quality young plant compost and handle the plant as little as possible and never by the stem.
Growing on
Keep these plants warm and well watered but not over wet. Allow them to dry out slightly in between watering and keep a close eye on them. If you have used a quality compost it should contain plenty of nutrients to feed your plants as they grow, but if they look pale then feed them with a weak liquid plant food. When the roots can be seen pushing through the base of the pot they are now in it is time to decide whether you are going to grow your tomatoes in large pots, growing bags or in the greenhouse border (or for outdoor tomatoes in the vegetable patch). If the danger of frost has passed you can plant your tomatoes outside, if not then pot into larger pots or containers or plant into growing bags that can either be grown on in the greenhouse or moved outside when the weather improves.
Feed with a dedicated tomato food when the first truss of fruit has set, this will deliver all the necessary nutrients and trace elements to encourage strong healthy plants and a good crop of fruit.
Trouble shooting
Tomatoes aren’t immune from pest and disease problems. One of the most difficult ones that has been prevalent in recent years is tomato blight. Greenhouse tomatoes are more immune to this problem as it is spread by spores in wet weather and the greenhouse glass protects the plants from infection for longer. In bad years, it will reach those grown in greenhouses too and it doesn’t matter whether you are an experienced gardener or not, your plants can be completely decimated. you can choose tro grow varieties that show some resistnace to tomato blight and the greenhouse offers some protection too, but there is little else that will cure the problem. The first sign of trouble is balck pathches on the leaves which spread to the stems and then the fruit. Remove all infected leaves as they appear and destroy. Avoid touching uninfected plants afeter handling diseased material and bear in mind that this fungal disaease also attacks potaties. Destroy badly affected plants quickly and don’t add them to the compost heap.
