Gray Leaf Spot
Gray leaf spot is a tomato disease that usually only affects the leafs. It most often starts with the older leaves which turn dark grey to brown. It can be seen on both sides of the leaves which usually dry out and fall off. One of the best ways to shield against this is to choose plants that are more resistant to it. But, if you do end up with this in your garden the you should consider removing the plant. There are other tomato diseases to watch for though the main thing is to watch the leaves they seem to be the first to show stress.
