[Ma Lowe]

I use pots in the greenhouse at home for them too. After planting them, they are given a pint of water each, and not watered again for a week. I then only water when the compost is visibly dry, and they get a good soak. This encourages strong searching roots, as opposed to lazy surface dwelling roots that are prone to drying out easily when the hot weather comes.
This applies to everything in the ground too. After an initial soaking at planting time, nothing is ever watered. at all. Ever

Totty

Not even after a long period of dry weather (which ok it happens rarely here  )

[Totty]

Young plants that have not established themselves would get a good soak if things got drastic.
I manage to get loads of organic matter worked into the soil in winter, and want the plants to get their roots deep down into it as opposed to sitting near the top waiting for a daily trickle.
Well worked soil holds it's moisture well even in drought like conditions. It's rare to push your hand into the soil and feel nothing but bone dry soil for any more than a few inches.

Totty

[Ma Lowe]

That's very interesting Totty and think I will try the same with my plants and see what happens. If it means not having to wait for everyone to use the tap on the plot then I am all for it.
I may well have been over watering my tomatoes so maybe this is something that would work better.
When you say that you give the tomatoes a good soaking if the compost is dry do you do this from the bottom or top.  As my pots have holes about an inch up e side of the pots it's difficult to water from the bottom.

[cadalot]

The way around that is to cut a length of small bore plastic pipe an inch higher than the pot and push in the corner if square pot or anywhere on the outside if round and water into the bottom of the pot. I used and recycled the round plastic tubes from some solar lights I bought a few years ago.

[Totty]

I should have mentioned, I only let the compost get on the dry side to establish them, when the first fruits are setting, the toms get watered religiously at seven int mornin, and seven at night. Big fluctuations in moisture levels will lead to split fruit most of the time.

Totty