composting: to worm or not to worm

Haven't checked out this site in a while, but now that Spring has finally come, I'm back with questions!

Last summer I set up my first compost bin.  It's been filled mainly with grass, leaves, small twigs, and other gardening/lawncare byproducts.  Some food scraps and paper, but not much.

The compost has never really gotten as hot as it's supposed to.  There's definitely some activity, but it certainly isn't anywhere near the 100+ degree temperatures that aerobic composting is supposed to produce.  In fact, it froze during the winter and just started up again in the past few days.

The dilemma I'm facing is whether to add worms to the pile.  I know that worms make great compost, but I understand that they can't survive in very high temperatures.  I don't HAVE very high temperatures, of course, so I'm not sure if that's an issue.  That said, I'd still like to figure out how to get those very high temperatures, since I understand they're critical for sterilizing any weed seeds in the pile.

If I add worms, and the temperature starts to get too high, will they just crawl down into the soil beneath the pile?  That wouldn't be so bad, since presumably they'd go on to improve the soil in my lawn.

From another angle... Any tips on how to trigger that super hot aerobic composting?

Sorry for such a long post.  Thanks in advance for any guidance.

Your pile is composting - just very slowly. 

To get a hot compost, you need something pretty big.  At least three or more feet across.  And then you need to get the right carbon to nitrogen ration (30:1) (usually just barely on the not stinky side) and the moisture level needs to be just right.

If you don't do all of this, everything will still compost - just slower. 

Don't bother adding worms.  They are probably already there!

Yes, there is stuff you can buy that will make for hot compost.  But for that stuff to work you still need a big pile, the right C:N and the right moisture.

Thanks, Paul.

How hot does the pile have to get to effectively kill weed seeds?  I might invest in a compost thermometer to start monitoring this.

It depends on the seed.

Super expert composters will shoot for a temp of 145-150 and no hotter:  this kills all seeds and nearly all of the bad guys while leaving some of the good guys intact.  Getting it hotter than that (160) is easy.




 

I've read that pill bugs (rolly pollies, mini garden armadillos) work even better than worms- and they're more fun to play with!

I think it's important to understand that different fauna (if you will) move into the compost pile at each temperature stage, so it isn't just a case of whether or not you have earthworms or pill bugs, etc., it's what temperature facilitates the activity of which organism that contributes to decomposition.  There are 3 main groups of decomposers: fungus, bacteria, and invertebrates (think of them as the FBI of composting >, and you could break those down into 2 groups - micro-organisms (fungus, bacteria, and microbes), and macro-organisms (earthworms and insects).  If you have a hot pile, those groups will move in and move through quite quickly and you can easily see the progression as the pile heats up and then cools down; if you have a cold pile that is slowly decomposing (over months rather than weeks), it can take a lot longer to catch on that that progression is actually happening...

you don't have to worry about adding any of those things - they'll come on their own as the temperature of the compost pile dictates...

another note about worms: 'added' worms are usually the 'red wigglers', which reproduce fast and are such darling and hard workers. However, I found out recently that they are not native to our PNW soils, and we should be careful about spreading those worms to areas that don't already have them. All my compost, and nursery plants, etc. are full of them already. I luckily live pretty urban and I doubt the worms would cause damage. But if I were to do it again, especially if I was somewhere rural, I wouldn't use red wigglers. I'd follow some advice from a friend of mine and use worms that are already in that ecosystem. They may be slower to reproduce, but there won't be any unforeseen impacts on the soil food web.

As long as the compost is touching soil, I wouldn't worry about adding worms.

Worms that are naturally existing in the environment will find the compost and get to work away from the hot core. You will get the benefits of their castings without the cost of adding them and potentially losing them to an inhospitable environment.