My war on powdery mildew. With potassium bicarb and sesame oil .

[SmittenGarden]

I've been lazy and bad... I still haven't re sprayed and now my large zuc is completely white again...however I intend to spray agin tomorrow if I get the chance and this time I shall take a before and after pictures.

[Zenbaas]

Bit or a bump for this thread again.

I seem to have a yearly issue with powdery mildew due to the lack of sun my tomatoes receive.

I see potassium bicarbonate mentioned a lot so I though this would be the way to go. Now I see in the OP the mix is 3 tablespoons per gallon whereas on other sites I have seen 4 teaspoons(or one heaped tablespoon) per gallon.

Also is the oil necessary..? Will a sticker spreader added to the bicarb also work instead of the oil?

[b54red]

I use the diluted bleach spray to keep it out of my garden with great success. The trick is to use it early and make sure to hit the undersides of the leaves, especially on the squash type plants. If you wait til the mildew is bad then most leaves with bad infections will dry up and die from the bleach spray but that is true of almost any disease that is allowed to get too bad. If you decide you want to try it start out with the milder solution first and make sure to spray very late in the day or very very early.

Here is a link to a good thread on using the bleach spray.
http://tomatoville.com/showthread.ph...t=bleach+spray

It also works on most bacterial and fungal diseases of almost any plant in the garden and has no affect on beneficials or pests for that matter. If done correctly it can be a big benefit. Another useful product is a copper spray which is better as a preventative than as a curative.

Bill

[Zenbaas]

Thank Bill I've tried it before and will continue using it but it truly nailed the plants a bit. That could be because of a high concentration or just having very bad mildew. Even my seedlings seem to be affected so I was looking for a "milder" solution. I guess I can keep on dropping the concentration of the bleach solution I'm using and try and see where a good median is.

[b54red]

Originally Posted by Zenbaas

Thank Bill I've tried it before and will continue using it but it truly nailed the plants a bit. That could be because of a high concentration or just having very bad mildew. Even my seedlings seem to be affected so I was looking for a "milder" solution. I guess I can keep on dropping the concentration of the bleach solution I'm using and try and see where a good median is.

If you have the concentration right it will not damage healthy growth at all. I use it on even small tomato seedlings that are only a few inches tall if they are showing signs of damping off with no problem except on the ones that are already affected by the damping off.

A few years ago I got tired of mildew destroying my squash just as it was starting to make despite using fungicides and keeping them mulched. I was spraying some tomatoes with gray mold problems and just went ahead and sprayed the squash. You are right it did give the badly infected plants quite a hit but it did nothing to the healthier plants with little mildew on them except for spotting a few of the leaves where the mildew was. Since then I have been much more proactive with my squash plants and try to give them a spray with the bleach solution about once a week. I start doing this as soon as the leaves get big or I see just the slightest bit of mildew on the underside of a leaf. This seems to get the mildew before it can get a good foothold on the plants and without the damage to the leaves. By doing this regularly and keeping some Sevin dusted on the base of the stems for squash vine borers I can continuously get squash til I get sick of eating them. Once that happens I quit the regimen and within a few weeks they are covered with mildew or the vine borers have taken over. I use the same technique for cucumbers also; but they are not quite as susceptible to the mildews since I keep them running on a tall fence.

Bill

[Zenbaas]

How often do you spray your tomatoes..? Also once a week..?

[b54red]

Originally Posted by Zenbaas

How often do you spray your tomatoes..? Also once a week..?

I usually spray my tomatoes once every week to 10 days early in the season unless the weather is extremely dry with low humidity which rarely happens until late summer down here.

Bill