Tomato plant leaves turning yellow?

Question

what can i do?

Answer 1

If it's just the older leaves at the bottom, don't worry. They do that. If it's the newer leaves at the top, you may be overwatering. Or you might have some kind of disease like white powdery mildew.  

Answer 2

Here in the UK this marks the beginning of the end of their season and, that being the case, there is nothing one can do.

If this is not the end of your season I can only think that you may be overwatering. Good luck. h

Answer 3

I'm not an expert but I do have a few suggestions about your plants.

You might want to put stakes in with the tomato cages (I do this) and then rearrange everything to take the weight off the lower branches. This will also help provide more air circulation among the plants. I'm in a (very this year) hot and usually sunny climate so I keep the plants fairly close together for shade. Again, be careful to keep them well staked so they don't topple on each other. I use twine to tie my plants and check them often to make sure none are bending too out or down.

I keep the soil consistently watered to prevent any wilting, and I never water during the middle of the day.

You might want to get some bone meal and epsom salts to sprinkle into the soil, and stop using sprays (except for organic ones to control aphids, etc.) I had another member of the forum tell me that the less "coddling" of tomatoes helps her get the best results, and I have come to agree with her. Sometimes we tend to make a witch's brew of the soil in our attempts to "help" our tomato friends!