Question
My pumpkins plants have been growing great. Lots of big leaves and so many flowers and bees I thought I would have many pumpkins. I am still hoping for that. Yesterday morning I was checking them and noticed white spots on all of the leaves. I looked at the soil and it was clean except for some of the flowers that fell off have more white but hairy white on them. I removed all of the offending flowers and watered off the leaves. I just don't know what this is or if and how to treat. I do not use pesticides and really hope this doesn't spread. I live in Connecticut and we have had some hotter than normal weather lately (90 degrees and up) and the humidity has been sky high, not sure if this may have something to do with it?

Answer
Suzanne, your plants have been infected with powdery mildew, a fungus disease that is especially prevalent in wet and/or humid conditions.
 
To combat this disease, it is best to order seeds that are resistant to this disease. Most seed catalogs such as Park Seed and Burpee list the various diseases which the hybrids were bred to resist. Also, never water in the evening as this lends to this disease due to the water not evaporating as quickly in the evening. It is always best to water in the morning.

Once the plants are infected, you must use a copper based fungicide. I use a product called Soap Shield, and it works great. But it is best to start spraying in early summer to prevent the disease, because once the plant is infected, powdery mildew is extremely difficult to cure. Attached is a link to this product if you are interested. Your local garden center also has fungicides that control this condition.

http://www.gardensalive.com/product.asp?pn=8066&ss=Soap%20Shield

I hope this answered your question. Good luck, and please write again if I can ever be of assistance.
   
Regards,    

Mike