Mary Beth is winging her way back to Block Island this morning to visit family, check on her bees and do a lot of weeding in the garden she left behind. Sounds like a great vacation, no?
In the meantime, I don’t know about you, but the powdery mildew that’s been a minor concern over the past few weeks has erupted into a full-blown pain in my you-know-what. In SoCal we’ve had cloudy mornings, and sometimes whole days, since — wait let me go get my garden journal (I’m inordinately proud of myself for actually keeping up with my entries this year) — June 2nd or so. This is due to the marine layer known locally as “June Gloom” and it makes pretty much perfect conditions for powdery mildew and other fungi like rust and black spot to take hold in our gardens.
Powdery mildew has been popping up more frequently in my garden and in my clients’ gardens. And if I’m having problems, I’m pretty sure you are too — or you soon will be. There are a few things you can do to make it a little less of a problem like providing good circulation around plants, keeping your beds clean of leaf debris, and using mulch. Also, organically-grown plants are more resistant to it because soil enriched with organic fertilizers and amendments encourages the growth of beneficial fungi that eat the bad stuff. (Whereas plants that are grown using chemical fertilizers, sprays and amendments are more susceptible because those chemicals kill the good along with the bad.)
As time goes on and you continue to use organic practices your plants will become healthier and more resistant, but especially here near the coast powdery mildew is all but unavoidable. The solution is to spray your plants when you see that the bad guys are beginning to win the war. Spray your plants, tops and bottoms of leaves, early in the morning to avoid drift and to keep the spraying from harming any beneficial insects. Then spray again in week to 10 day intervals (and after rain for those of you who get it in the summer) until things calm down in about 3 weeks or so. You won’t eliminate it completely, but you’ll knock it down enough that it won’t be a problem.
Here are a few organic solutions to help control the problem.
Anti-fungal #1 — Milk
Milk works well, especially on cucumbers. Use milk full strength or mix a 50-50 solution of milk and water (one part milk to one part water). Spray tops and bottoms of leaves.
Anti-fungal #2 — Compost Tea
Make a batch of compost tea by filling a 5 gallon bucket 3/4 full of compost , add water. Stir it every day and let it steep for a week. Strain out the solids. Dilute to between 4 – 10 parts water to one part tea. Adding kelp to the mix is said to improve its efficacy.
Anti-fungal #3 — Garlic
Put 10 cloves of garlic with 1 pint of water in blender and let it whirl. Let it sit for a day then strain out the solids, mix with 1 gallon of water. This is strong stuff which will kill good and bad, so be careful!
Anti-fungal #3 — Dish Soap
Add 1 tablespoon of liquid soap to 1 gallon of water. This works well for aphids and other pesky critters too.
Mix 1 teaspoon liquid soap with 1 tablespoon baking soda and 1 gallon of water. Shake the sprayer as you work to keep the baking soda suspended in the solution.
I know there are lots more formulas out there. Does anyone have a favorite they’d like to share?