Answer: The flies are there because they know there's rotting (splitting) fruit and/or other decaying vegetation. If you remove all the split tomatoes from your garden, along with any rotting vegetative debris, you won't have a large fly population. Sadly, cherry tomatoes often split just as they mature. There are some varieties resistant to splitting so if you plant cherry tomatoes again, look for split resistant kinds (listed on the back of the seed package). For now, you'll need to inspect your plants daily and harvest any that are typical size and color. If they're not quite ripe you can set them on your kitchen counter and they should ripen within a day or two.
In general, vegetable gardens need to be watered regularly and fed a couple of times during the growing season. You can side dress them with compost or aged manure or use a general vegetable garden fertilizer in amounts as recommended on the package.
Best wishes with your garden!
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