Any oil spray can smother and suffocate insects, and in that respect neem oil makes no difference between good and bad bugs.
So when you spray neem oil, do it first thing in the morning or late in the evening, when the good bugs are least active. That way you won't hit any bees or other beneficial insects directly. The neem oil spray will dry before they land on the plants, and only the insects trying to eat your plants will die.

What if some gets in the flowers as will probably happen?

Some people claim the toxicity of neem to bees is exceptionally low and unlikely to do any damage unless they are direct sprayed in excess.

Too bad honey bees aren't as tough as the wasps living in my eaves. Those things are immortal.

Shouldn't hurt the flowers at all, Just follow the recommended instructions on the label for mixing.

I mean it would hurt the bees feeding on the flowers in the morning?

Morning would be the worst time to spray neem, for the sake of bees.

What I am asking is if I spray in the evening and get neem in the flowers, is it likely to cause some significant harm to the bee population and the pollination of my fruits, due to the bees visiting the next morning? (I think there also may be some squash bees I have seen some guys sleeping in the flowers)

With many curcubits, the flowers only last a day, then close up and die, whether the fruit it pollinated or not. I THINK this may be the case with cukes and melons, but I'm not 100% sure.

So the bees leave the plants in the evening, the flowers close up, and the new ones open early in the morning, when the bees are most likely to visit, as the pollen is best then.

This means that to minimize harm to bees, late evening is the best time for spraying neem, if quite necessary.

Thing is, it's not necessary against PM, as there are other fungicides available at least as effective as neem, and less prone to burning the foliage.

Suggestions please? I tried Daconil and it had seemingly little effect.

The females definitely only open for a day but it seems the males open more than once.

This post was edited by Peter1142 on Mon, Jul 21, 14 at 14:42

Immunox - the version w/o insecticide

Immunox for garden, You can find it on Amazon which is where I get it, I spray early morning around 5 or 6 am. an I have no problems.

In general, the existing powdery mildew will remain in spite of applying fungicides -- unless you remove the leaves.

Fungicides protect new growth. So it must be there because the mildew is present.
Neem oil is an "exception" as it can get rid of limited infections.

Nothing can clear/save/make-good-again engulfed leaves!

As has been said, read the label for cautions as well as directions for use.

I find it interesting that you are inquiring about the safety of neem after already having used Daconil...

Bees only visit during the day and they go straight to the flowers. So if you spray late in the afternoon, just before dark, the flowers have not opened and the bees have gone home. So with Neem oil there is a minimal chance of hurting the bees.

Another thing is that you can watch out and not spray the flowers. You can do this if you have just a few plants but if you want to spray a big field that is another matter.

@howelbama, as far as I know Daconil is 100% bee safe, and it wasn't sprayed anywhere near the hard skinned fruits that are months away from harvest.

I've read with interest how neem oil is relatively save for bees, but I've just come in from my zucchini patch where the powdery leaves are covered with bees who are unmistakably gathering the powder, or eating it. Most had full pollen pouches. I've observed this for the last few days, and finally able to believe my eyes, decided to google to see if anyone else has had this experience.

I found a woman who posted on a site that she observed lady bugs eating the powder off her powdery leaves and took a picture of it.
I'll try to upload the address.

Consequently I have grave doubts about spraying the leaves at any time when the bees are actively harvesting the powder. Yes, I know it sounds weird. I would love to hear from anyone else who might have some experience with this. Why would fungus be a beneficial substance for bees or lady bugs????

No bees were eating my powdery mildew, that's for sure. :)

The Immunox didn't do much. My plants are pretty much all dead at this point, except for butternuts which seemed to be more resistant. Still got a nice harvest, though.