Here's what I do, the recipes are organic.

Early blight is powdery mildew I think. It happens when there's a big difference of temperature between nights and days, so there's water on the leaves in the morning, and it lasts because the sun doesn't dry the dew fast enough.

3 to 5 pieces of garlic, skin and all, boil them for half an hour, add a teaspoon of natural black soap, and spray without diluting.

Of course wait for it to be cold.

As garlic is full of sulphur, it kills the early blight.

You can use sulphur if you're not organic.

I tried it and it worked.

Some mix no fat milk with water (1 for 10) but I never tried so can't tell.

For late blight, the recipe is :
half a teaspoon of baking soda,
for one liter of water,
and a teaspoon of soap.

But I didn't try it yet because late blight happens, well, later !

I hope you'll get more recipes from more experienced gardeners.

Good luck with your gardening !

FrancoiseFromAix, How much water do you use? and do you just use the liquid from boiling the garlic as your liquid for spraying? Also what time of day do you spray? Thanks.

I use Immunox for PM on curcubits. When I mentioned this last year, it freaked out a lot of people here, but the stuff is good. It's not listed for blight on tomatoes.

Be sure to find the formula "for gardens" without insecticide.

Itilton, So you don't use it on Tomatoes?

I'm sorry I didn't add the quantity of water. It's one liter for 3 to 5 pieces of garlic.

It depends on the size of the pieces. In the head of a garlic, there are those around which are usually bigger than those Inside.

And this garlic tea must not be diluted, you use it pure once cold, just add some natural soap to make it stick to the leaves (and the soap kills the aphids if there are some).

I spray in the evening, or on a cloudy day, because the sun could burn the sprayed leaves.

I spray the whole plants, even the flowers, and it doesn't destroy them.

What destroyed some was my enthusiastic overwatering and the billions of white snails enjoying the wetness :-(

I cook 5 liters of garlic tea, which is about 1,3 gallon I think, since you guys use those weird measurements ;-)

I don't know if it's effective on blights, not being listed for same, and I don't get PM on tomatoes, so I use chlorothalonil on tomatoes and potatoes to prevent blights. PM is a big problem for me here on curcubits.

Both PM and blights are in the better-prevent-than-they-to-cure category of problems. Noting that two different organisms cause different diseases called "blight".

I did spray my tomatoes, and they don't suffer from it (I mean, those that were not overwatered !)

My stupice have flowers and little green fruits, and are doing great. They're loved by snails, but with the garlic, not so much.

My zucchinis and butternut squash were getting sick, I sprayed two evenings and yesterday at lunch time when it was cloudy, and they're cured.

But then I sprayed all of them, so I don't have a not sprayed one to compare.

Perhaps it's just a coincidence and they would have get cured in the same way if left alone.

I didn't do it scientifically to compare.

It's just the simple organic way that people do here and taught me.