Did a search and didn't find a definitive answer; I have quite a bit of charcoal ash (No easy to ignite petroleum products.) and I was wondering if it would be good for my tomatoes?
I scatter fireplace ashes in my garden. I guess the best way to find out is to use them on a couple of plants. They'll either grow or keel over dead LOL. Good to see you, where 'ya been?
You're talking about charcoal ash from briquet's OldGuy?
I have no idea what ingredients go into making a briquette, but like So Lucky said, ash will raise the ph some. I'm guessing that your soil is already leaning towards the alkaline side because of your southwestern location.
On the other hand isn't that what biochar is all about?
Most BBQ briquets are just compressed charcoal made of burned sawdust, mixed with a binder. Much like regular wood ash after burning.
Spuds can suffer from ashes, so keep that in mind in future when/if planting any. Lots of other veggies can use the added potash, phosphate, calcium, and magnesium it offers. The high calcium can sweeten the soil to much if your not careful, so don't overdue it in one area.
I would think that the carbon content may reduce nitrogen in the soil, as part of the composting process. I'm just not sure how much it uses, say in comparison to wood chips, but I'm thinking less, as it's already broken down 99 percent.
Beets like some wood ash mixed in. Don't put in very much, though, or it will harden up your soil. I'm about to embark on my fire pit with small surround patio. I have heavily tilled the area and tomorrow will add a big pile of wood ash that I have saved up to mix with it. After tilling in the ash, I'm going to run my truck over it to compact, and then start the construction. I shouldn't have much trouble with weeds, at least for awhile, and the ground underneath will harden up nicely.
This is NOT what you want to do to your flower and vegetable beds!!