 show their resentment to the heat by turning some yellow leaves, especially on the bottom. So mulch along the peas, if you haven't already, mulch at the base of the peas, untreated grass clippings, you know, those that haven't been sprayed with an herbicide, weed killer. Grass clippings work very well, or if you have other type composty mulches, mulching at the base of the pea row will help greatly.