Looking after seedlings and young tomato plants can be a tricky business.
Just how much water to give, especially if new to growing tomatoes, can be a difficult decision to make. The method is to keep the compost just moist so that it is neither wet or completely dry.
This is actually impossible as compost or soil drys-out rapidly on a hot day, and if you are away from the house your little plants could be dying of thirst in the hot sun.
The first thing to understand is that the more water you give your plants (over a period) the less roots they will grow. This is owing to the fact that roots need air as well as water and a consistently sodden soil will stunt root growth owing to lack of air.
That means if you over water your plants, when the time comes that they need a good root system to absorb water on a hot day, they may not be able to take up all that they need.
This a a pic of a variety called Glacier and it has a good root system with strong, thick white coloured roots.
When plants are in pots they should be stood in a tray of water for 5 or 10 minutes to thoroughly absorb water and soak the whole of the compost area.
It's best to not water again until the compost is almost dry to allow air back into the soil.
If the leaves start to wilt that will be a sign that you have left them a bit too long without water! For a quick recovery, spray them with a mist of water and water them from below again.
I realise that this can be time consuming if you have to keep your eye on the plants and try to judge how moist the compost is just below the surface!
However, the best start a plant can be given is a good root system and this will pay-off with a healthy life and a good harvest.
More about watering and feeding tomato plants here.