Powdery mildew

My gardens have been growing great. The pumpkins were flourishing, the zucchini and squash were getting huge, my peppers were producing like crazy! Everything was great until powdery mildew came into the picture. At first I did not realize what it was. It just looked like some powder. Then it started to turn my pumpkin black and make it wilt. Here is a picture:

By the time I found out what it was, I tried to stop it. I sprinkled baking soda all over every infected plant (by this time it was the pumpkins, zucchini, squash and watermelon). Alas, half the crops I planted in February are wiped out. This has been a sad gardening year for me :(  Here are some lessons I learned:

1. Don't plant all of one family of crop, otherwise one disease or insect will damage them all.
2. Circulation is key in Florida. My garden is bordered by fence on two sides, so the air is pretty stagnant. This created an environment powdery mildew loved.
3. Prevention is key to avoiding gardening blunders.
4. When I see something out of the ordinary for a plant, I need to actively look up what it is, instead of waiting until it is too late.

My pumpkin is completely gone. My watermelon is small, and might make it. My squash and zucchini has nice sized veggies on them, so some may survive.

In the meantime, my tomatoes are all sprouting. They are green and not ready to harvest yet, but soon. My green beans are growing like crazy! They have outgrown the 6 foot tall bamboo support trellis I made for them. And my peppers are still producing.

I am sad that half my crops are gone already. It's almost May, and not a good time to just start planting things. Oh well, I will tend to what I have and plan for October!