What causes the leaves to start turning brown and wilting, even when they have water? They are in plastic mulch and have drip irrigation. Some have not even produced fruit and they are drying up and dying. Also, all my tomatoes' leaves have started turning upward, leaves turning brown and dying. What causes this? They are also in plastic mulch and have drip irrigation.
Squash and Tomatoes
Certified GKH Gardening Expert
For the squash, it sounds like vine borer. This article has more information:
For the tomatoes, it could be a wilt fungus. This article has more information on that:
Or it could be leaf curl. Here is more information on this: