Question
Last summer I grew cucumbers, squash, zucchini, lettuce, and red peppers.  The squash, zucchini, and cucumber leaves all started developing a white mildew-looking stuff that then spread and destroyed all the vegetables.  What is it and how do I prevent it for this year?  Can I use anything if it does start to develop again?

Answer
Beth, your plants contracted a fungus disease called powdery mildew.  Powdery mildew is spread through spores in the soil or the air. The spores are splashed onto the plant during rain or when blown by the wind. Although the disease seldom proves fatal, it can cause the plant to prematurely lose its foliage which could result in a smaller harvest.

The best treatment for powdery mildew is lime sulfur.  This is an all-purpose fungicide which will help control the disease.  Other options include copper and fungicidal soap.  Gardens Alive markets an excellent copper-based organic fungicide called Soap Shield.  You can research this
product online at:

http://www.gardensalive.com/prog_display.asp?PROG_NBR=5

Make sure you spray at the first sign of mildew.  This will prevent it from spreading.  Like all diseases, if you wiat until the fungus spreads, it is too late.

I hope this helps.  Good luck, and please write again if I can ever be of assistance.

Regards,

Mike