The first thing to know is that tomatoes come in two types - climbing, correctly known as ‘indeterminate’ tomatoes, these keep growing all through the season, becoming long and messy vines, and the other type is bush, correctly known as ‘determinate’, which means they grow into a bush and have a single flush of fruit that ripens together. To grow them you have to plan how you are going to keep them contained and neat before you start.
There are a vast range of tomato varieties available so don’t just buy any seed, think about what you are going to use the tomatoes for. If you will be doing a lot of preserving or sauces, you might look at determinate tomatoes that are thick and meaty. These will bear all at once so you can get your preserving work over an done with at once, and they are not too juicy. Most people buy ‘Paste’ (also known as 'Plum') tomato seeds for this use such Roma. For sandwiches and salads you should look for either small cherry types, standard or ‘beefsteaks’.
There are so many varieties that come in so many colours and sizes that you will have as much fun choosing as growing.
Before you Plant Your Seeds
Make sure you have a good place to grow your tomatoes. If you are growing indeterminate tomatoes you will need a sunny spot with a fence, trellis or frame to grow them up (alternatively you can grow them up a long garden stake). For determinate tomatoes just about any sunny spot with good soil will do, even a large pot or tub.
Sowing Your Seeds
Tomatoes need warmth to germinate. You can sow them in a pot outside when the weather warms up in spring after the chance of frosts has passed, or to get them going a few weeks earlier, sow them in a pot and place them in a warm and sunny place indoors until all chance of frost is over before planting them outside. Make sure you use good potting mix, not garden soil which is not open enough for use in pots.
Tickle the top of the soil with your fingers, then sprinkle your seeds over the top and add a bit more soil to cover. Give them a little water, just enough to keep the soil damp, but not too wet.
While Your Tomatoes are Germinating
While you are waiting, build up your bed with good soil and old manure. Another thing to keep in mind is to make sure the place to plant your tomatoes has well drained soil. If it is likely to get waterlogged you will need to build up the bed so that excess water drains away and doesn’t rot the roots.
When your plants are around 10-15cm tall you can plant them outside in the position you have chosen. Be gentle with them so you don’t damage the roots or break the stem/s. Give them a sprinkle of water with some very dilute liquid fertiliser in it. When they start to grow strongly you can start them on full strength fertiliser but not while they are still settling in.
Tomatoes are pretty easy to look after. Make sure you water them well once or twice a week during hot and dry weather and give them a boost of liquid fertiliser every three or four weeks. If you live in an area that gets very dry summers, it is a good idea to mulch around the plants with a thick layer of straw to hold moisture near the roots, but make sure the mulch does not lie against the trunk.
Although you don’t need to prune tomatoes, indeterminate types do produce a little better when you do. Pruning makes the plants more manageable and also directs the energy of the plants into the fruit rather than making more leaves.
The basic pruning method it to keep the plant at only two to four stems. You need to pinch off any extra stems growing close to the bottom blossom cluster and any extra stems from stem joints after you have chosen the main stems to keep. Using garden string tie the stems to the fence, trellis, frame or stake for support as required but be careful not to squeeze or restrict the plant.
Pests and diseases
There are many pests and diseases of tomatoes. Most bugs can either be picked off by hand or sprayed with a mixture of detergent and water. If your plants wilt and die unexpectedly and you are sure that they have received enough but not too much water, they might be infected with a serious wilting disease. These diseases stay in the soil for a long time so in the future you should either plant your tomatoes in large pots or plant them in an area of your garden where no tomatoes have been grown for many years.
You should harvest the ripe tomatoes as they colour up and slightly soften. Leaving them too long may attract pests, but even if you pick them a
little unripe they will continue to ripen on a windowsill with no loss of flavour. Hey, even if they don’t all ripen before your first frosts there are plenty of delicious, green (unripe) tomato recipes you can try.