Ashes in Compost

I understand that wood ashes are wonderful to use to sweeten the soil, and I also understand that wood ashes are fine additions to compost. But, I was wondering if anyone knows about using wood ashes that have some ashes from burned diseased plant material (at least I think it was diseased) in them. Can they be composted? Would the compost process 'cleanse' the material of the disease?

If the process of burning up the plant material didn't get rid of the disease organisms then composting it definitely won't. But I think chances are nothing survived burning so I doubt you need to worry about that. No idea if ashes in general can be composted or not--hopefully someone else will know that.

Good question. If it were me I would use the ashes sparingly at least at first....... mainly because I believe they are concentrated mineral..... what composting does among other things is (ultimately) blend all materials together into the humic result .... which will vary in its chemical composition according to what went in there in the first place..... Been a bit too long since I looked at any technical info so maybe someone else will have more specifics to offer.

Ashes are roughly equal to lime and should be used on or in your soil not the compost pile. You will no doubt hear that some do but subject to a soil test that shows you need to raise PH. Both lime and ashes raise the PH. General gardening is best done within a PH of 6 - 6.5. There are trace minerals in both lime and ashes. The lime however comes from the sea. You might suggest correctly that ashes have trace elements brought up by the plants. That is correct yet you may not need the PH adjustment that comes with either.

Thanks for your input, everyone.
Logically speaking, what you say ecrane3 would be what I would think, too. With the exception of the organisms that live in the compost pile. For instance, the worms. Would the worms eating these ashes finish off any leftover disease? I guess I'll have to dig deeper into this little mystery of mine and see what comes of it. I KNOW I've read about it somewhere -- just don't remember in which magazine, book, column, webpage...
Kylaluaz, you wouldn't have any suggestions on where I could start looking would you? I'm leary of using the ashes just in case. I'd be quite upset if I contaminated an entire compost pile by using something inappropriate in it. So, anything you've got I would surely welcome.
Docgipe, I live west of the Cascade Mountains where the soil tends to be quite acidic. Everyone around here is usually trying to counteract this - except where they are growing their blueberries and azaleas ;) - so raising the pH isn't a bad thing. I've read that adding the ashes to the compost pile is fine as long as it doesn't exceed 5% of the total mass. Do you know anything about the ashes of (possibly) diseased plant material? It's a conundrum to me. If they shouldn't be used in the compost, thereby not in the soil either, then what exactly do I do with them? By the way, thanks for the bit about lime coming from the sea. I didn't know that.
Green gardens to you all!

I would be very surprised if any plant diseases survived being burned. To me there's a question of whether ashes will do anything for you in the compost pile--I can see spreading them on the garden if you're trying to get your pH up but I'm not sure they'll help the compost at all. However if you're convinced they'll be good for your compost and all you're worried about is diseases I really don't think you have anything to worry about. The things you've probably read about diseased plants not belonging in compost are if you're putting the plants themselves in there (without burning them first). Compost won't get hot enough to kill some disease organisms on its own, but if you burn them first then the burning will kill everything that's in there.

Well made compost will indeed hit 115 -125 degrees even higher. Three days of this will kill most seeds and plant pathegons. Anything that goes through an earthworm is even better when it comes out in the casts. Burning kills the living biology needed in the organic process.

One would worry far more about harsh chemicals including NPK man made salts and lots of chemicals that should be labeled as bio-cides because they do in fact kill the biology in the soil and affect life all the way up the food chain in a proven negative reaction to mankind. We got along just fine up to about the end of the last world war without the harsh chemicals. Something had to be done to save the munitions plants and this is where chemical fertilizers manmade were born. To this day the chemical man made fertilizers and man made sprays to solve all the worlds problems have made those problems in fact more difficult to control and literally killed off the biology in the soils and burned out the organic content that would help the soil recover. That is where we are....out there raising tomatoes that look sickly and taste like cardboard and carrots that taste like the spray they were raised in.

You all can do much much better in your own garden patches to raise good looking tastey and healthier garden produce. Enjoy what you can grow without most if not all harsh chemicals.

Hi Greenmum, I went and looked in the Rodale Book of Composting for you, about wood ash -- although I did not search out anything about other types of ash, still, perhaps this will be useful.

It says wood ash can be a valuable addition to compost in cases where soil is too acidic but to only use the lightest dusting as it is a very strong alkalinizing agent and also increases soil salinity. Side dressing with wood ash, also very lightly no more than 2 lbs per hundred sq ft, can also ameliorate an over acid soil. Ash adds potash and calcium but so do some other materials that are not so dangerous in terms of unbalancing soil nutrients.

Hope that helps.