Since mid-summer, I’ve been spraying the cucurbit leaves with a baking soda and peroxide solution on a more or less weekly basis (see July 12, 2014). Why? To ward off powdery mildew.

I’ve tried other approaches such as pruning the affected leaves and spraying with diluted milk. The first method was futile (too little too late). The efficacy of the second method was difficult to assess (I was using pasteurized milk, not raw). Perhaps the progress was slowed but, in the end, the plants were overcome.

The baking soda solution, on the other hand, seems to be working very well. The first signs of powdery mildew did not appear until very late (the end of August) and the spread has been slow. The mildew has been limited to a small fraction of the leaves.

Unfortunately, the spray is not completely effective. Powdery mildew is still present and, eventually, it can still have a detrimental effect. The cucumbers are more susceptible but the summer squash have suffered a bit, too.

Also unfortunate is the fact that the spray does nothing to prevent bacterial wilt. We have had fewer cucumber beetles this year (who knows why?) but clearly they’ve given our cukes the kiss (well, bite) of death.