August 31, 2013 - Powdery Mildew

Every year my squash and cucumber plants eventually succumb from powdery mildew, but it's just something I've always lived with.  I've never bothered with sprays or any kind of control, other than chopping off offending leaves until there aren't enough of them left to support any further plant growth.  Last week I noticed my new planting of cucumbers was  showing a lot of PM.  Mr. Granny does love his cucumbers, so I thought "What the hey, might as well give them a spray and see what happens".  I mixed up 1 tbsp.powdered milk and 1 tsp.of baking soda in a spray bottle, added water to fill and a few drops of liquid dish soap, then headed out to the garden to apply it to the leaves of the cucumber plants.  According to what I had read on line, this wouldn't cure already infected leaves, but it might keep the PM from spreading. Two days later, I checked on them, and couldn't believe how much better the plants looked!  I gave them another dousing, and now, another two days after the first application, the difference is very promising!

Very little powdery mildew remains on the leaves!  Even the leaves that were badly infected are mostly clear now.  I'm thinking I'd better buy myself a new garden sprayer, just for killing off PM.  A small spray bottle would never work in a squash patch.


24 comments:

  1. I sprayed one year for PM, but it didn't last. Sometimes I'm just too lazy to do it. Though I keep thinking I need to do more fish emulsion sprays. It helps a lot too. I think I got around to it twice so far this year. Every year I promise myself I'll be better about it. Every year I fail.

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    1. My sprayer is full of diluted fish emulsion that I was going to apply to the garden "someday". It seems like a gallon of spray lasts forever. I think my sprayer needs a larger nozzle!

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    2. Daphne, you make me feel much better about my garden laziness. lol, I always promise myself that I will spray with compost tea more regularly, and I never manage to do it. The summer calls me and working in the garden in the heat just doesn't appeal.

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  2. I'll have to try that (next year). Sounds promising; I sure have a problem with PM.

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    1. Ray, it remains to be seen just how often I have to spray. After every rain? No problem with that here, LOL. But I also use overhead sprinkling. Will I have to be out there twice a week spraying? I doubt I would be very good about that! Would twice a month do the job? I could probably handle that.

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  3. Glad you've had luck with the spray. I'm going to have to write this one down. I don't have a problem in the vegetable garden with PM, but my phlox and heliopsis by the house always seem to have a problem--probably poor air circulation there.
    Did you experience any problems with clogging on the nozzle with this spray?

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    1. Sue, no clogging in the pump sprayer. Of course, I haven't used the last of the concoction, so I might have half a bottle of curdled milk by now. Couldn't smell any worse than that fish fertilizer!

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  4. I'm trying hard not to visualise spraying my veg with fish emulsion (a substance with which I'm not familiar). Does it smell of fish? I think I would prefer the milk option!

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    1. Mark, it's an excellent non-burning fertilizer, and it smells worse than anything I've ever smelled before in my life!

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  5. This is great, Granny! I have PM on all my squash plants. But can you use regular milk instead of powder?

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    1. Mts. R., of course you can. It's one part milk to 9 parts water, or 1/2 tsp. baking soda to 1 qt. water. I just figured if either/or worked, maybe both together would work better, LOL! I just used the powdered milk because it was handy. I didn't stop to figure out how much, just tossed in a tablespoon of it. The dish soap was to make it stay on the leaves.

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    2. And I know you are MRS. R., not MTS. R.! I'm typing while still half asleep :-D

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  6. good to know! i gave up on growing zucchini because of the pm and really missed them this year.

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    1. Kelli, I wish I could give you the half dozen or so that are shrivelling up in my refrigerator :-D

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  7. Isn't it simple and effective? I just use regular milk with the baking soda. You can also add a little Neem oil, which has fungicidal properties. A tip: don't leave it out in the sun all day. And they recommend spraying it before it rains, since the PM spreads when the leaves are wet and you want to knock it down as much as you can before the rain. Unfortunately, the strain of PM around here this year seems resistant to anything I try, including Green Cure (potassium bicarbonate) and Serenade.

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    1. David, I've had really good luck mixing plain corn meal (the kind you'd use for making cornbread) with water as a fungicide. Even digging a bit of the dry cornmeal into the soil at planting time seems to be pretty effective on plants that are susceptible...in my case, that would be garlic. I keep my spray bottle of milk/soda on the patio, in the shade. I checked it today, expecting to find curdled milk, but it looks nice and clear.

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  8. I use this on my peas (sugar snap, snow and podded).
    Sometimes it makes all the difference in the hvst if I can keep the plants growing for another few weeks. So even if it's temporary-it's worth it.

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    1. Barbee, I was impressed with how healthy the plants looked after just one spray. I just want them to give Mr. Granny another month of cucumbers!

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  9. Well, now I'm going to have to go find the pump sprayer and try it. I tried diluted powdered milk in a spray bottle but it kept clogging. I was doubtful if it would do much good anyway, so I haven't bothered to go find the bigger sprayer. Now I might just have to try to salvage them. The squash look pretty bad at this point, but it's just getting to the cucumbers and I'd really like to keep eating those.

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    1. Amy, I mixed mine up in an old Windex bottle, and it's been sitting outside in the heat all week with no clogging, lumps or curdling. I'm tempted to just add some to the big sprayer that's still half full of fish fertilizer.

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    2. We had a sprayer (maybe 1/2 gallon size?) that we used to wet the popcorn ceiling in the kitchen. I mixed up some powdered milk & baking soda and filled it about 1/2 full of water, & sprayed about half my plants tonight. It was lots easier than using the spray bottle. I figured I'd test half & see if it seemed to make a difference.

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    3. I did the same thing with my 1-gallon sprayer tonight. I filled it half full and drenched the zucchini and the cucumbers. Much easier than using a Windex bottle!

      The old cucumber hill was ripped out a couple of weeks ago, all but one single vine had completely succumbed. That one vine had PM, but a couple of green leaves and a blossom or two. I sprayed it this week when I sprayed the new cucumber plants, and it is recovering already! I thought it was a complete loss, but it looks like it will pull through now.

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