Stick your finger down in the soil and see if it is dry. There is not just one rule for watering because in a pot with light soil it would be different than in the ground in clay soil.

Crazy-Plant-Boy, that's 35-40 degrees Centigrade, right?

[Which translates into 95-104 degrees Fahrenheit, for all us hidebound Americans.]

Can you tell us why they died, or at least what the symptoms were?

Are they in pots (and if so, how large) or the ground?

Yes that's centigrade, sorry! I watered them every day/ every two days so I may have overwatered them.. But the leaves were turning brown and, for lack of a better word, crunchy.. So it looked like they were under-watered..

They're in hanging pots about 30-40cm tall and 20cm wide. They're young so I thought that was a good size.

Is anything wrong with what I'm doing or the size of the pots?

This post was edited by Crazy-Plant-Boy on Sun, Jan 20, 13 at 2:17

That would be what we'd call an 8" pot (8" diameter) which is way too small for a tomato plant, even a "young" one. Minimum recommended is a 20" (55cm) diameter pot and that is only for small varieties. Bigger is better and your plants are big ones.

From your description of the symptoms it is possible they were rootbound in the pot. But that is just a guess without a great deal more information or better yet a photo.

Dave

I'll try and take a photo later on.. It's almost 2:00 am here!