How Can I Keep My Grapes From the Rusty Leaf Problem

Question

I used a natural weeb oil that killed the grapes.

Answer 1

I use a product called Green Cure to keep things like powdery mildew, rust and black spot off my roses, pumpkins, cucumbers and such. I see no reason why it would not work very well on your grape vines. Here is a link for you on this product so you can check it out;
http://www.greencure.net/