There is a lot of misunderstanding about powdery mildew. First, it is not a single organism but a whole bunch of different fungal organisms, most of which are very host specific. As an example, powdery mildew on roses is not the same creature as powdery mildew on poppies, which is not the same as powdery mildew on cucurbits. The cucurbits (squashes and cukes) can share a PM with sunflowers but several different species of PM will affect cucurbits.

And scientific evidence seems to indicate that PM is not actively transmitted through seeds. In fact, in most cases, it requires viable (living) plant tissue to survive.

I can't tell you anything about the Japanese beetles as fortunately, these are not yet an issue in my area :-)

Thanks Gardengal. I was aware that there are many types of powdery mildew, but didn't realize how host specific they were. Count yourself lucky that the Japanese beetles have not found you!

I have rarely seen powdery mildew here, and I wonder if it's the strong breeze. Do you have an area where the wind tunnels through more strongly?

I did see my first signs of powdery mildew on lungwort this year, in an area protected from the wind. When NHBabs said it was often a sign of stress that made sense to me. We have been so very very dry here this year (after mid June, that is) and the lungwort was starting to brown on the edges. I pulled out the bad parts and have been adding some deep watering when necessary. It has certainly helped. I'll have to watch them in the future since they don't get wind.

Wind is a possibility of how this specific powdery mildew arrived here. We have strong winds from south to north. (There are a lot of gardening neighbors to my south and none to my north.)

Other possibilities are that something I composted might have contained the spores, or perhaps they lay dormant in the soil since day one, seeing as I've never grown poppies in that garden before. Maybe this strain of powdery mildew mutated on its own to create a more potent poppy killer. Or perhaps the DEA created this strain of mildew in a lab and unleashed it. Who knows? I put nothing outside the realm of possibilities.

The really odd thing is that I currently have two sunflowers and a hill of crookneck squash untouched by any mildew this late in the summer. Normally they begin to get tinged at this point, not enough to ruin the squash or sunflower seed harvest, but enough to damage some foliage. This year, not a sign of powdery mildew on anything since my poppies bit the dust.

I dig a hole and dump the canful of beetles into it and cover it up with soil well pressed down. Nothing comes out of the holes, ever. It's impossible for a dead animal to lay eggs. There aren't many beetles here this summer at all, thank goodness.

On the question of mildew. I grew a great cucumber last season. And it was so healthy and produced a ton of perfect cucumbers. I saved the seed, thinking I had a winner, this year, the plant seems to have a mild case of some kind of fungal disease. So I doubt that it was the seed, but had to be the conditions. We have had a very consistent amount of rain this season. Usually coming just when I needed it and in the amount I needed. I've not had to use the sprinkler very much at all. So, I give up on trying to figure out if I get PM, why. [g]. I will just pull them, throw them out in the trash and plant in a different location next year.

And here, the beetle population has been very low this year. I don't normally get a lot of Japanese Beetles, but do get a small amount of Oriental Beetles but this year, I think I pulled a dozen or so and that was it.

What amazed me this year, was that I didn't see ONE red lily leaf beetle. I found that amazing. No foliage damage at all on any of the lilies. What a blessing that was!

Thanks Prairiemoon. The red lily beetles have not made an appearance here either, or at least there is no visible damage to my tiger lilies. I agree it is a great blessing to be ridded of them. The release of the predatory wasps was apparently a grand success.

As to the Japanese beetles, the application of grub-eating nematodes this spring did not prevent them altogether but seemed to delay their emergence long enough to allow roses to bloom, so it is probably worth it to re-apply them next year. I've decided to continue to dispose of the dead beetles in the trash, even though it's more trouble than just emptying the bucket into the weeds. Considering all the varieties of parasites whose eggs can survive encysted, inside even dead worms, and in the soil for years during subzero winters, it's not a stretch to imagine that nature may have armed these disgusting beetles with similar survival strategies.

I agree that there are so many factors involved in mildew, and the lack of it, from year to year that it would impossible to figure it all out. I was just thinking along similar lines about the futility of guessing how a new species of plant or tree will grow in our gardens or on our land. One can pick a plant or tree suited to the growing zone and put it in a place where it will get the requisite amount of water and sun, in soil of the type this species is known to prefer, but it's never a sure thing that the plant will be happy where it is put. There might be neighboring plants or trees in the vicinity that are sending out chemical "keep away" signals, a lack of the correct fungal strain under the earth needed to support it, or any number of other factors that we can't even guess at.