Garden mildew

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(Host) Got milk? Commentator Charlie Nardozzi says that milk appears to be good not only for bones – but also for some common ailments in the garden.

(Nardozzi) Gardeners are known to wax poetically about natural things the general public finds slimy, squishy, and rank. Only a gardener can be fascinated with a slug’s slime trial, a mass of spittle bugs, or an overripe, oozing tomato fruit. It’s not that we aren’t sensitive to the grossness of thesenatural phenomena, it’s just we find it all so intriguing — especially how it affects our gardens.

So with that rather coarse beginning, let’s talk about mildew. I’m not meaning the mildew that is growing on those forgotten leftovers in the back
of the refrigerator or the mildew on your shower tiles. No, I’m talking about the mildew on plant leaves this time of year. Powdery mildew, specifically, is a ubiquitous fungal disease that thrives under our late summer conditions — day temperatures in the 80Fs, with humid nights.
It also loves damp, shaded areas with little air movement. Does it sound like your yard? Mildew quickly forms a white film on the leaves and flower buds and eventually will kill them, cutting short any flower show and weakening the plant.

I wouldn’t mind powdery mildew so much but it loves some of the best garden plants in the landscape. The queen of late summer blooming perennials is the tall phlox. They provide a flower show incomparable to any other perennial this time of year. However, I’ve watched many a good crop of ‘Bright Eyes’ phlox succumb to mildew in a few days. It also can be found on lilac, bee balm, roses, and vegetables such as melons and squash.

As with any disease, the first line of defense against powdery mildew is to grow resistant varieties. ‘David’ phlox has won awards for being mildew resistant. ‘Simplicity” and “Bonica” roses are touted as resistant to this fungus. ‘Donald Wyman’ lilac and Prairiefire’ crabapple also resist the disease. That’s well and good if you like those plants, but what about all the other varieties in your garden? How can you keep those plants safe and
mildew-free?

For years, gardeners have heard about baking soda as a preventive spray to stop powdery mildew. Now researchers in New Zealand and Brazil have found
another pantry pest control for powdery mildew. It’s milk. It seems if you spray a 10% milk solution (1 part milk, 9 parts water) on plants it prevents and kills powdery mildew. Scientists tried it on melons and grapes, but there’s no reason to believe it won’t work on phlox and roses equally as
well. They’ve tried raw milk to skim milk and it works equally as well.

So break out the water, milk, and soda and start spraying your favorite late summer flowers. This way the only mildew in your yard will be in those old sneakers under the deck.

This is Charlie Nardozzi in Shelburne.

Charlie Nardozzi is an all-around gardening expert with a special fondness for tomatoes and roses.

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