Powdery Mildew

**Booklover** · 09-02-2010, 12:03 PM

I have had a terrible problem with powdery mildew this year. It seemed to spread to all the squash, zucchini, beans and pumpkins. They were trying so valiantly to bear fruit when all the while they were dying. I ended up ripping the plants out and putting them in the trash. I was afraid that even the heat of the compost pile wouldn't kill it.

Is there a way to stop it? I know it's airborne, but what about the soil in which the plants grew. Is it contaminated? Is there some organic remedy? (I don't use chemicals). The first I noticed it was this spring on my lilac leaves. I've never seen lilacs with it before this year.

I'm hoping Durgin will have some advice.

**Russ** · 09-02-2010, 12:12 PM

First.... You did the right thing by not composting the infected plants. Good job.

Some things you can do to avoid it in the future...
No overhead watering. it helps keep the leaves dry so they don't get it.

Plenty of space between plants. This extra air movement helps the plants dry out quicker. Prune if you have to.

No late season fertilizing.

Cure...
I haven't found one.

**Booklover** · 09-02-2010, 12:21 PM

Ok, my plants grew like crazy this year and became monsters! So there was definite overcrowding. I pruned for airspace, but it wasn't enough.

As for overhead watering---I didn't water at all this year. We had so much rain, too much, actually. But I see those 2 factors caused it.

Will it overwinter in the soil?

**Russ** · 09-02-2010, 12:25 PM

Originally Posted by Booklover

Will it overwinter in the soil?

No, as long as all the plant debris is gone.

**Booklover** · 09-02-2010, 12:27 PM

Thank goodness! That was what I was hoping to hear. Thank you so much for the advice. I really appreciate it. Our gardens are our children, you know.

**Russ** · 09-02-2010, 12:30 PM

be sure to rake up all of your lilac leaves

**Booklover** · 09-02-2010, 12:32 PM

Good point-I didn't think of that. They haven't dropped yet, but I will definitely do so when it's time.

**Durgan** · 09-11-2010, 11:31 PM

Originally Posted by Booklover

I have had a terrible problem with powdery mildew this year. It seemed to spread to all the squash, zucchini, beans and pumpkins. They were trying so valiantly to bear fruit when all the while they were dying. I ended up ripping the plants out and putting them in the trash. I was afraid that even the heat of the compost pile wouldn't kill it.

Is there a way to stop it? I know it's airborne, but what about the soil in which the plants grew. Is it contaminated? Is there some organic remedy? (I don't use chemicals). The first I noticed it was this spring on my lilac leaves. I've never seen lilacs with it before this year.

I'm hoping Durgin will have some advice.

I have given up on Powdery mildew. The spores are always present. This year I got not one cucumber due to this powdery mildew. I have tried all the nostrums to no avail. Now I consider it a misery, that hopefully does not appear next year. My view is; if the weather is against you there is no cure.

Don't wet vegetation if watering is about the only precaution one can take.

**frugalfranny** · 09-12-2010, 12:30 AM

Yep......me too, booklover.

We had a horribly wet spring......and well........it went downhill from there.

One thing 'they' rec., and I get sloppy about, is cleaning the garden tools with bleach.......do you do that after working on the affected plants? (1 part bleach to 4 parts water)

If we have a wet spring there is just no stopping it...

**lparker** · 09-12-2010, 10:35 AM

We've always had PM on lilacs in the 50+ years that I remember. Cukes and squashes also get it every years. Way back when...Dad used fungicides. I generally just let the plant die. It doesn't seem to make any difference if the old leaves are removed or not...it's always back the next year.

Some info I Googled -

"Powdery mildew fungi are host specific, meaning the different powdery mildew fungi infect different plants. The powdery mildew on your lilacs will not spread to your grapes or your roses. However all powdery mildews favor the same conditions."
Controlling and Preventing Powdery Mildew on Plants

And Use of Baking Soda as a Fungicide is a trick I'll try next year.

**Booklover** · 09-12-2010, 11:11 AM

Thank you for the links, lparker. I am really interested in the baking soda remedy. I am bookmarking these for next year.

**Booklover** · 09-12-2010, 11:14 AM

frugalfanny, I have not been disinfecting my tools. Thank you so much for this! I have always tried to be careful walking and touching so as to not spread spores (we have late blight now, too, here) but never thought of my tools.

This will be remedied today.

**Booklover** · 09-16-2010, 01:35 PM

Durgan, I didn't get a single cucumber, either. I ripped my plants out, too. Broke my heart to see them trying to form fruit as the whole plant was dying.

This is the first year I couldn't grow a zucchini, either. Same thing happened. And I pulled all my pumpkin plants when powdery mildew started on them. It was too late for them anyway since the slugs and earwigs destroyed all the blossoms. When they finally left them alone, I didn't have enough growing season left for pumpkins. Too bad, because we certainly had enough heat and water for them this year.

I should start a thread on earwigs, because for the last 3 years they have bothered me more than anything. Complete infestation. Grrrrr!

**krbshappy71** · 09-16-2010, 02:11 PM

Thank you for this. I had it attack my Bleeding Heart and two Columbines. They were in large pots near each other on the porch, thankfully did not spread elsewhere since they were contained.

One Columbine I cut way back to nubs and the new leaves are not having an issue, I believe the other Columbine and the Bleeding Heart are dead. Dead, dead, dead.

**Durgan** · 09-16-2010, 03:53 PM

Originally Posted by Booklover

Durgan, I didn't get a single cucumber, either. I ripped my plants out, too. Broke my heart to see them trying to form fruit as the whole plant was dying.

This is the first year I couldn't grow a zucchini, either. Same thing happened. And I pulled all my pumpkin plants when powdery mildew started on them. It was too late for them anyway since the slugs and earwigs destroyed all the blossoms. When they finally left them alone, I didn't have enough growing season left for pumpkins. Too bad, because we certainly had enough heat and water for them this year.

I should start a thread on earwigs, because for the last 3 years they have bothered me more than anything. Complete infestation. Grrrrr!

There are several effective methods to control earwigs. I don't have them in sufficient quantity to bother.

It is a good idea to remove all spent vegetation in the Fall to discourage many bugs from over-wintering. I remove all weeds and cultivate to destroy as many eggs in the soil as possible. I also rake back any mulch and apply compost to disturb the critters.

I muse about the much touted no-till practice, since it would appear to me to be a great place for over-wintering insects. I can only assume that copious quantities of "cides are utilized.