veg garden ph

[Stew Corman]

I had seen several posts long time ago about the benefits of using fireplace ash blended into the vegetable garden as a means of providing many minerals...we burn oak primarily. A recent search shows that most plants like scallion and tomato need slightly acid conditions, but the ash is obviouly basic in nature. I heavily mulch the garden using rotted leaf mulch so there is plenty of organic matter blended in. If upon testing, I need to lower the ph due to the ashes, what is typical for this application ... I know that lime is used to raise ph, but unlike grass lawns, a veggie garden is not supposed to get past 7.0

I was thinking of spreading oak shavings from woodworking as a means to add acid.

TIA for any tips

Stew Corman

[dps]

Oak shavings will reduce the pH of your soil for a while, but as it decomposes they will tend toward neutral pH. In the process they will tie up nitrogen, so you will have to fertilize. In general, the more finely divided the wood is, the faster it will take up nitrogen and decompose. Sticks won't hurt, but sawdust is a problem. Shavings could be a problem.

If your soil is in the range ph 5.5-7.0, I wouldn't worry about it unless you are trying to grow something like blueberries, which need acid. If it's above 7.0, sulfur is a way to produce a more lasting acid reaction without affecting soil nutrients.

[simy1]

it's more complicated than that. Ash pH is 10.4, and I actually give ash to my tomatoes because it provides Ca, K and because the tomatoes taste better that way (my soil is naturally acid - I disagree that tomatoes prefer it acid. They will grow at any pH between 5.5 and 7). Other plants, like beet, chard or onions, grow better with a bit of ash and actually prefer it right around 7, and will pout at 6 or below.

You can use wood ash as a substitute for lime, and as you say, if you mix it with woodchips or coffee grounds you can get a near neutral soil amendment. Also ash is fairly rich in micronutrients, essentially providing everything except N, P and S. Mixing anything with leaves will generally bring the pH towards neutral. I give ash and wood chips to the tomatoes, garlic, radicchio and fruit trees, and ash manure and leaves to most everything else. I give woodchips and coffee grounds to various cranberry lingonberry and blueberries.