I live in N. Texas, zone 7b, and we had a very mild winter, and so far a fairly mild spring (mild meaning not gotten very hot yet). We've been in the 70s on average the past month, with a few days in the 80s.

I started my peas in late January, and they came up and grew slowly, but started growing much faster around early March. Today they are about 7ft tall, have given us about 3 weeks worth of peas, but most of the bottom leafs are yellowed and dying. The top of the vines are still green and flowering, but their new leaves are all very small. Some of the newer pods are smaller. Also, normally I get red spider mites that start attacking them. And this year because its been fairly wet, powdery mildew has been bad too. This seems to happen most years I have tried planting peas. I know they don't like hot weather, but is it worth trying to fight off the powdery mildew and spider mites, or are the plants just spent and weak, and their imminent downfall is inevitable?