Using HOT compost....

American Canyon, CA(Zone 9a)

My husband picked up a whole trailer (at least 1 to 1 1/2 yards) of compost from our local garbage facility. They take all the yard waste from the bins that they pick up from peoples home each week and turn them into this compost. The whole load cost us $3.50. That is pretty much free.

They say it is certified organic and reccomended for use by the Organic Materials Review Institute (OMRI, something like that). They send off samples to the lab every week and, because it is heated so hot, it burns off any pesticide, herbicide etc. residues. This sounds odd, but I tell you...out here in California it is pretty hard to be Organic unless you really are "walking the walk" and I am sure someone would have blown the whistle on the stuff it it weren't.

ANYHOW, our intended use was to just use it as a mulch around some front yard landscaping we just completed, lots of 4 inch perennials, gallon shrubs, some roses, trees etc.

The compost was so hot it was steaming, and when I put my hand in the middle of the pile it dang near burned me! However, once I spread it out on the driveway and hosed it down, it cooled pretty quickly. Do you think this will be okay as a mulch, no more than 2 inches thick? I know not to put it right up to the plants but my husband spread it while I was at work and he did get pretty close to some of the smaller stuff. I plan to keep it pretty moist for at least a few days to help it further cool down.

McLean, VA(Zone 6b)

Because it is literally hot to the touch, I would worry about using it yet. I'm not sure that allowing it to cool off for a few days is the answer. You may need to allow it to rest for a longer time since it seems that it was just 'actively' composted. I would probably wait for a few weeks.

Can you call the facility and see what they recommend timewise?


Compost that hot is not ready to be used. It will be about the same temp as the air when ready.

American Canyon, CA(Zone 9a)

Let me update...we spread it out on the driveway and it cooled down pretty quickly, then kept it watered well this past week, after it was spread on as a mulch. It is working great and the plants are already happy. I knew I couldn't put it on while it was still physically hot but I wondered if just cooling with water and air circulation were enough, so far so good.

Anne Arundel,, MD(Zone 7b)

I have seen piles of pure wood chips that are steamy hot, just from the huge bulk of the pile, and you know there's no way its loaded with N. Maybe with that bulk of compost they are running its extremely bio active.

Monte Vista, CO(Zone 4a)

I'm using some compost (grass clippings, kitchen veggie waste, egg shells, coffee/tea, chicken manure mixed with wood shavings, and sandy dirt from my yard) that's only been 'cooking' for about 2 months in just a pile in the garden. I try to turn it every week or two. I mix it with plain dirt from the yard to tone it down, throw back any clumps that haven't composted well enough, yet, and, since I grow in straw bales, place it on top and in crevices of the bales, then transplant the seedlings and water in. The plants seem to love it.

Virginia Beach, VA

If it is hot then it is not ready to be spread. Wait for few more weeks.


Magnolia, TX(Zone 8b)

You did good, water the hot stuff cools it and dilutes it faster, you just have to be careful, being in Ca your soil is a bit sandier than a region of say, black gumbo clay, so the hot stuff has a better chance to cool faster, cheap was a good price!

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