You know, I just had an interesting experience with pH adjustment. I decided to save oodles of money and not buy new potting soil for my greenhouse this spring, and use old potting soil augmented with compost and the bottom soil of my pond. My pond is built in an old cat tail swamp that is 200 feet below a huge barn that housed thousands of sheep for a hundred years. The barn burned down a few years ago. Anywho, all that sheep manure washed down into the cattail swamp. I built the pond, killed off the cat tails, and now, when it dries out every winter, I can go down and shovel up a gold mine of 100 year old composted sheep manure. I have no idea how deep it is, but its deep. Every spring, I bring up as many wheel barrow loads as I can, and throw it in all the flower beds and in the vegetable garden. Works great.

So, in my money saving frenzy, I mixed this potting soil up and planted a few hundred plants in 1/2 gallon pots. Things weren't going well, I thought I had various diseases, this and that, and finally had the pH tested, it was around 8.2 and varied from pot to pot. Well, no wonder.

So, I figured the way to lower the pH was to add an acid, and distilled vinegar seemed to be just the ticket. So I experimented with a dozen plants, adding distilled 5% vinegar cut 3:1 with water, to see if I couldn't lower the pH. These dozen plants, the first day, didn't do anything. The second day, they started turning dark green, looking very healthy. I waited a third day, they were still going great. So I did it to all the plants.

Long story short, I killed them all. It took a week. Soil in a pot is not soil in a garden. Today I used my $50 Christmas Gift Certificate and went and bought 30 tomato and pepper plants.

Interesting story. I wonder if you did a weeker vinegar solution and waited a week between treatments what it would do. Seems like a little venigar would go a long way. Did you test the PH after the plants died? Maybe it was like 3 or something. Cheers!

I probably should, but I'm still too annoyed with myself. I have used a crystalline "Soil Acidifier" which is some kind of diluted sulfuric acid in a dry form, about 10 years ago I bought a 50 lb sack. I've used that successfully to grow peppers and chili, which do much better in a slightly acid soil. I just put down a spoon full between the plants down the row. I get bigger, thicker, and more peppers, so its worth while.