Worm Composting Grass Clippings

Dave Pawson
#1. June 22nd, 2010, at 8:37 AM.

Caution with grass clippings. In warm weather, especially if the clippings
are fresh, the bio action causes a temperature rise that the worms won’t
like. Left, the grass will ‘burn’ to a sort of grey black ash which really
isn’t nutritious at all.

Kuan
#2. June 23rd, 2010, at 2:42 AM.

I agree with Dave that it will heat up quite a bit if left in a pile like that. My outdoor hot compost pile which comprises of mostly grass clippings (DH is a landscaper) normally heats up to about 153F to 160F. It takes about 2 weeks for it to cool down. If I turn it and add more moisture (& more grass clippings), it will heat back up again.

Worms will move in once it cools down though.

Kuan

Dave Pawson
#4. June 23rd, 2010, at 5:54 PM.

One more thought, perhaps more general on mixing
vermiculture with composting? I need the high temperature
that grass gives me to kill the weeds, but I don’t want the
high temperatures to keep the worms alive!
I guess this means when mixing the two, you do need to take
care what you throw on the compost [vermic ] heap.

Mmmm

mark
#5. June 24th, 2010, at 7:59 AM.

Well, I have used a mix of grass clippings and sawdust on top of one of my worm bins and everything is okay. Grass clippings are quite a tricky material to deal with in bulk. I add quite a lot to my compost heap mixed or layered with “brown” materials.

Joel LeGrand
#6. June 27th, 2010, at 2:42 PM.

I have let most of my grass clipping go though a heat before putting them on my veggie raised beds for mulch. But after cutting my orchard
( blueberries, raspberries & blackberries), I mulched with clipping of dry straw, leaves & grass/weed matter, with no problems at all. I do not see why a small layer of grass would hurt. I have had the same compost pile as Kuan. I had the same temperatures, but when spread out & not piled up the heat should not build-up. If you mix it with a little soil or brown matter then you should not have a problem.
Thanks Bentley, we learn by doing!

Dave Pawson
#7. June 27th, 2010, at 2:48 PM.

Joel said “when spread out & not piled up the heat should not build-up. If you mix it with a little soil or brown matter then you should not have a problem.”

I think that’s the key. But when I’ve just cut the lawn… what
to do with the clippings ‘meanwhile’? Two heaps?

Dave

Joel LeGrand
#8. July 18th, 2010, at 10:42 PM.

on # 7, if one has the time & space, two heaps would do it. You use off the cold heap as the hot one cools, then rotate piles.
What of inorganic chemicals in compost materials, will it break down or transfer to the humus, then the plants. Not to say anything about the worms.

PC
#9. August 15th, 2011, at 5:38 AM.

Easy composting mower bag trick. 1) After mowing do nothing put mower away for 1-2 weeks or more. Then remove the grass material and add top of worm bin should work fine!