They might not be dying because of drying -- they might be responding to being overwatered.

Does the top of soil or about 1" of soil actually feel dry when you water them? Or let's try it another way. Don't water one of your tomato plants (but continue the same for the others) and see how many days it actually takes to have it show some signs of needing water in your garden.

Watering daily? That will do it. Leaves first turn yellow, then necrotic and they dry and die, all from over-watering.

Is this plant in a container or in the ground? If in a container, what size?

Dave

Hmmm. I'm having yellowing too. I wonder if it is over watering for me also. Mine are in 3 gallon nursery pots with a very sandy, very well draining soil. I am in S. AZ so I am watering every 6 hours for 5 mins with .5 gallon/hr misters. I applied an organic, chicken manure based fertilizer at planting and have been foliar feeding with kelp once a month. Mine are grape tomatoes and they are setting fruit and we just ate our first three ripe ones yesterday but they look kind of sad.

karoleana,

They are probably starved for nutrients. If the soil is as well draining as you say, overwatering is probably not the problem, but the nutrients have probably all drained out by now. Organic nutes take time and a proper soil food web to break down and be taken up by the plants, this can be difficult to do in a container... I would switch to a balanced synthetic fertilizer and feed them on a more regular basis given the frequency of your watering and the fast drainage of the soil you are growing them in...

karolena - I agree with howel above - all containers require regular supplemental feedings - weekly is common. Plus your plant is very likely in far too small a container. Very, very few tomato plants can do well in only 3 gallons. They are quickly root bound in such a small pot and that means water and nutrients run right through the pot.

You might also want to do some reading here on the problems with using dry/granular organic fertilizers in containers, especially small containers. There is no soil food web or bacteria in there to convert the organics to a useable form.

Dave

Thanks Dave and Howel.
My father-in-law follows The Garden Master system http://thegardenmaster.com/. I got some hand me down 5 gallon bags from him but they were not holding up well so I bought what I thought were 5 gallon nursery pots on Craig's list. They turned out to be 3 gallon. He feeds his once a month but it is a special concoction he got from the system. I guess his stuff is extra potent and that 2 gallon difference is significant. I will up the foliar feeds to weekly and see if that helps. I was not aware of problems with using granular fertilizer in containers I will definitely look into that.
I was leery of using a synthetic fertilizer precisely because I wanted to establish some good bacteria and was afraid synthetics would be a detriment to doing that. The rest of my veg looks good but maybe I will run into similar problems as they mature.
Thanks again for the help!

I don't no what happened to mine they turn yellow too and and some of the leaves start to dry