This seems to be a timeless question - ‘why go to all the trouble and effort of growing your own tomatoes?’  There quite a few arguments put forward to support this question. 

After weeks of regular care, watering and feeding just when you are ready to start picking your own crop your local supermarket has an abundance of really cheap tomatoes.  But once you have tasted the wonderful flavour of a freshly picked fruit that you have grown yourself it all becomes clear.  It leaves no doubt as to why it’s worth all the bother.  But having said all this I had a disappointing season last year.  For the first time I tried growing tumbler tomatoes in a hanging basket.  I had very little fruit and that of a poor quality.  I know lots of people who have had great success using this method – it just didn’t work for me.  So this year I will be back to the more conventional ways.
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If you do decide to give it a try there are plenty of good young plants on sale in the garden centres.  But remember that these are tender plants and May can be a tricky month, late frosts are not unusual.  So for a while keep the young plants either in a greenhouse or on a window sill in a warm, light position.  Make sure there is enough space between the plants so that the leaves don’t touch.  Begin feeding each week using a proprietary tomato food.  When the root systems fill the bottom of the pots the plants are ready to be moved to their permanent site, having previously made your choice of the best growing system for you.  Any of the following have a proven success rate, large pots, 30cm are a good size, growbags, ring culture, greenhouse borders, or even in the ground in a sunny place outside.  A good tip is that deep planting results in more roots which in turn means more fruit.  If you are growing outside it is important that the young plants are hardened off for at least two weeks before planting. 

Unfortunately there are a few pests which are likely to be a problem and whitefly are amongst the most common.  It helps to hang yellow sticky traps in your greenhouse early in the season.  Even though they are self fertile tomatoes still need a little help.  Very, very gently tap the flower clusters as this will move the pollen to a different part of the flower.  As soon as the fruit ripens – pick it – by doing this you will be encouraging the plant to produce more.  .