August 29, 2016

Avalanche column

August 25, 2016

After my first sowing of summer squash, I decided to try a couple of varieties from High Mowing seeds. They were a variety of yellow squash and a variety of zucchini. Both of these were selected for their powdery mildew (PM) resistance.

Both varieties are very prolific producers, maybe even more so than my normal varieties. They are also a little more open growing than my normal squash. This I feel is what helps these guys to be PM resistant. They are a little more “viney” too and less bush like.

I am seeing some PM on the plants but nothing too pronounced like on my other squash. I am pulling the infected plants to see if there are some plants that are more resistant and then I could save seeds from these.

PM starts showing its head from mid to late summer when the humidity is higher, the days are hot and the nights are cool into the 60’s. PM starts as small “whiteish” blotches on the leaves and left to its own vices will soon cover the whole plant and then soon kills it.

Once you start to see PM you can slow the spread but the end is inevitable, death will follow

I find young vigorous plants to be the most resistant but the use of some sprays can slow the spread.

With all sprays the sooner you start the better the results will be. What follows is a list of some sprays most all of which I have used. I can’t say one is superior to the others.

1 tablespoon baking soda added to one gallon of water with ½ teaspoon of liquid soap. This can be added to clarified hydrophobic neem oil. Follow the directions on the Neem Oil container for mixing one gallon and the baking soda can be added to this.

1 1/3 tablespoons of cold pressed neem oil with ½ teaspoon of liquid soap in a gallon of water.

Or Actinovate (a natural fungicide) follow the label mixing directions.

Any and all of these will slow the spread but will not stop the eventual demise of the plants

I also like to cut and collect the most infected leaves as I harvest. I then dispose of these leaves in the garbage. If these leaves are left in the garden they will add to the infection.

In some years when I have enough seeds I will sow a third planting of squash around the middle of August, this is the best way to insure squash to the first freeze

Good luck and happy gardening!!