Vinegar treats mold on plant leaves

[a 10 percent satire content post]

This summer was very wet and warm enough to for mold to thrive on the veggies in the garden patch.

The American first reaction was to get the big guns: go to the garden center and get one of the fungicides locked up behind what looks like bullet proof glass, the stuff which an employee will release to you only if you answer a bunch of questions related to plants to treat, location of plants and your date of birth correctly.

If you encounter a very helpful employee, you will be asked a question in diplomatic mode, for instance, I understand you need to treat <plant a> and there will be no pets or children around?

If you fail to get the hint, tough luck.

The second reaction was, wait, vinegar should work.

Call it an unintended side effect of old school education, but the potent combination of basic chemistry and biology had left a memory about fungi/molds preferring neutral to slightly alkaline environments.

Vinegar, being acidic, should stop molds.

The next question was, how strong should the home remedy be in order to be both, hopefully, effective and safe for plants? The zucchini plants to be sprayed have relatively thick leaves, we figured, and if the solution was not strong enough, we could do another round with more punch.

We settled on about four tablespoons of vinegar in a liter of water for the five zucchinis on the last years' compost heap. It worked. The acidic water stopped the spread of the mold but was obviously a bit too strong because areas the areas of a leaf where the mold had dug deep into it, turned brown.
Areas to which the mold had spread just days ago, remained green and functional.

So, cauterizing part of a leaf may have been too aggressive but no harm was done - we did get a good zucchini harvest.

All this was done without support of the internet or books. Once fall came, we decided to give ol' Google a crack.

As usual, there was plenty of information, not merely on vinegar but other remedies, too.

This site on first plant aid in organic gardening looks good, not only because it confirmed that our first water plus vinegar solution was too strong.

The price of the home remedies is unbeatable, too: a few cents for a summer of treatment versus upwards of 10 dollars for certified poison.