What is the temperature of the composting material?

What is the moisture level of that material?

Earthworms live in a cool, moist environment and temperatures much above the mid 60's F are not something they will stay in very long.

Vermicomposting, composting with worms, is done in much wetter and cooler material than would be done in a compost pile.

kimmq is kimmsr

Not sure of the temp (nor how to measure it accurately) but it's definitely has to be warmer with the covers on. Perhaps I should leave the covers off in the summer months. I have a tree overhead that prevents direct sunlight throughout the day so it's not steaming hot.

The moisture level is adequate...not soaked, nor bone dry. Just a smidge above being damp I would say.

It's not like I'm trying to vermicompost, it's just that they appeared in my compost bin naturally last year and with the lack of them this year I think it's slowing down the process of breaking down compost material.

Are you sure in previous years they were earthworms? Or compost worms? (For example, are they smallish and red?)

Earthworms. I know because I grabbed a whole bunch to take the kids fishing.

Worms are not essential to composting. It's the microbes that do most of the work. If you are concerned that the composting process won't be successful without them, you don't have to worry about that. If you're just wanting more fishing bait, try the soil directly underneath the oldest and coolest pile. If you're operating the triple bin in a continuous batch mode, there should be a fresh hot pile that you're adding stuff to, a middle pile that you've stopped adding to but is still cooking, and a third that's in the curing phase. That last one is where you'll most likely find worms. If the temp and moisture isn't perfect in the compost itself, they'll be in the soil below.

How does your bin design? Can it be access by earthworm in the 1st place? If the bin is not exposed to the ground, but you found earthworms in the previous compost pile, could it be introduce unintentionally eg: soil/ compost with eartworms eggs use as activator??

I thought red wigglers(compost worms)were the worms used for fishing? Nancy

I think you can use just about any worm for fishing - they sell nightcrawlers too. Red wigglers might just be easier to grow in a worm farm?

I'm experiencing compost-bin envy! Nice setup!

Very nice set-up. I still think it's more likely that what you found before was compost worms (e.g. red wrigglers); usually they look a little smaller and thinner than regular earthworms. While it's possible that either type of worm could come up from ground, that gravel may be a barrier - which makes me think it's just as likely that something you put in the bins before had some live compost worms or cocoons that then found they were in heaven and reproduced. (This might especially be true if you added any manure or other unfinished compost from elsewhere).

They're not at all necessary but some find - including me! - that compost worms in a regular outdoor pile help a lot. If you find some source of compost or manure (they're often called manure worms for a reason) that already has compost worms active, just toss some in the bins (ideally when they are not in the hottest phase of composting).

If you find that helps, and since you have a classic three-section compost, when you harvest compost, try to take some worms and/or finished compost with cocoons (you can google to see pictures) back in your other piles/sections. If you're not in a rush you don't need to 'find' them all, just enough so that they have a chance to reproduce and colonize your other piles. If you can do that in spring, they'll have more good weather to help your compost along.

That said, it's not necessary, and some will say they don't like it at all, but I find compost worms in outdoor bins really do help. This low-impact approach certainly doesn't require a lot of extra work and can't hurt anyway.

If you put stuff in and you get compost out, it's broken down properly. Don't get too hung up on what happens in between or who's doing it. :-D

Just wondering the reason for the gravel?

For better drainage considering I'm laying a non-pressure treated wood frame (protected with tung oil) on top of patio blocks just inches above the ground. There's about 4 inches of gravel in there.

In my humble opinion, you're overthinking drainage. Build the pile on the soil and don't worry about it. The only time I did something like this was with an enclosed plastic bin used solely for composting very wet coffee grounds and food waste. Only after it became clear that there was not enough drainage into the clay soil and the compost was too wet.

Worms need a much wetter environment to live and work in than the compost bins you are building is meant to contain. Earthworms in that composting system are not significant workers, although they may move in later when the material is mostly finished composting.

Vermicomposting, composting with worms, is quite different than what you are doing.

kimmq is kimmsr

After nearly two years of use you cannot tell that there is gravel under the screening so it's really a moot point (maybe that's why I don't see the earthworms like I did during the first season).

There's no doubt that the compost is wet enough. Every time I rotate the bins I see that it is wet throughout except for the very top 2" or so of compost which I would assume is normal.

The only reason I built the covers was to keep EXCESS moisture out. During dry spells the covers are off.

In the bins you have wet compost is not what you want, moist is however.

What oes this material smell like?

kimmq is kimmsr

Its smells earthy like it should and is moist, not wet. I recently screened one bin's worth through a 1/2" hardware cloth screen on a wheelbarrow to help it break down quicker. The larger chunks caught by the screen were tossed into my second (working) bin. Problem is I don't have enough greens to get either of my piles warm enough. I spot spray my lawn for weeds so I can't add any lawn clippings to the bins. During the winter I only add coffee grinds (because the compost freezes solid and cannot be turned over)....once the weather warms up I add any and all kitchen scraps daily into my working bin. But I feel that this is still not enough greens.

I've been making compost for over 40 years and although I had compost freeze solid in the winter here (Michigan) early on once I learned how to make compost properly that was no longer a problem. I have not had compost freeze solid in about 30 years, some freezing on the outside yes but not in the more active center.

I learned long ago that if a compost pile freezes solid the material is holding too much moisture and the bacteria that are doing the digesting are not active enough because they do not get enough air to work.

kimmq is kimmsr

Even if it does freeze solid, it'll compost well once it warms up and thaws.

Well it really only froze solid during the brutal winter on 2013-2014 when the polar vortex was the big thing in the news (which happened to be the first winter my compost bin system endured). Not knowing this past winter wouldn't be quite as cold I decided to play it safe and only throw coffee grinds on top of my working pile. I did this because I didn't want to attract animals since I couldn't cover the material I was dumping with older material due to it being frozen. Once we hit late February I was able to start adding normal kitchen scraps because I was able to bury it in the middle of the pile without exposing it to scavenging animals (I once found a rabbit's severed head right in front of the compost bin on top of frozen snow which totally creeped me out).

I would not say that a compost pile that freezes is somehow made improperly. Plenty of gardeners have relatively cold and wet piles during winter and they freeze up like a popsicle. In spring they get turned if necessary and they finish up and make great compost. It's not that fussy unless you are trying to maximize output in the shortest time.