Once your tomatoes are well established it is a good idea to mulch them with wheat straw (hay is all we have available right now). Lay a few sheets of newsprint or cardboard on the soil around the tomatoes, peppers, and eggplants then cover the paper with the straw. This will help with multiple issues. First, the mulch layer will keep the soil moist, saves watering. Secondly and most importantly, the mulch layer will help with blight issues.
I hate being the bearer of bad news, but we know that eventually our tomatoes will succumb to blight. Early blight is a soil borne fungus. As water splashes on the lower leaves of our tomato plants it will carry fungal spores from the soil to the leaves, infecting the leaves. Infected leaves turn yellow. As the season progresses, the fungus will move upward on the plant until all the leaves are yellow and our tomato season will be over. To slow the progression of blight, a layer of mulch around the tomatoes helps prevent the spores from infecting the lower leaves of our tomatoes.
Normally, about mid May I'll also start a fungal spray program. Copper fungicides will help with out blight issues but don't go crazy. Spray only to wet the leaves, we don't want the copper spray to drip off the leaves as excess copper is not good for the soil. I'll spray every 10 days depending on the weather.
In the meantime, keep planting all your warm season crops. Happy gardening!