I've been putting in mostly vegetable matter--kitchen scraps and some garden waste. I wonder if:

1) I'm not getting a good mix of browns and greens? I'm now adding shredded paper, dryer lint, and will start adding vacuum contents (mostly pet hair). I get few leaves and prefer to leave them on the lawn. Do I need to purchase more "brown" stuff and, if so, what?

2) I'm maybe not keeping it wet enough?

3) I'm not being consistent enough about tumbling the tumbler composters? I really am sloppy about that, especially in the winter.

Any advice or suggestions would be appreciated. How critical are the possible problems I've identified? Is there something I'm missing? Do I need some sort of compost "starter" to get things going?

TIA, Lucy

It's important to remember that the microbes that will break down the waste need roughly a 30:1 carbon to nitrogen mix. The carbon is what they use for energy, thus the reason they need 30 times as much carbon as nitrogen. The nitrogen is used for protein synthesis. However, this doesn't mean that you add 30 "brown" parts to 1 "green" part. Waste isn't going to be pure carbon or pure nitrogen, the waste itself will have a carbon:nitrogen (C:N) ratio of it's own.

The trick becomes knowing the C:N of what you're composting, and trying to get your overall pile to a nice 30:1 mix. Newspaper, for example has a high C:N ratio of about 175:1. So in order to effectively compost newspaper, you'd have to come up with a waste that is high in nitrogen... but even the highest "green" materials still have relatively high C:N ratio. Veggie scraps, for example still have around a 12:1 ratio.

For a list of the C:N of basic compost materials, you can check this link, or do a Google search:

http://www.composting101.com/c-n-ratio.html

So let's say you're using newspaper (175:1), veggie scraps (25:1) and coffee grounds (20:1) to start your compost. Suppose you have equal amounts of each. The math would look like 175/1 + 25/1 + 20/1 = 220/3, or 73:1 ratio.

Now you have a problem... too much carbon. With too much carbon, the pile will take much longer to break down, since the microbes don't have the ideal environment to flourish in. The solution is adding more "greens" to the mix, so you decide to throw grass clippings (20:1) in. In order to get close to the magical 30:1 ratio, you would have to add 3 extra parts grass... the final equation would look like 73/1 + 60/3 = 133/4 = 33:1 ratio. Close enough. So your final addition to the bin would have been 3 parts grass, 1 part newspaper, 1 part coffee grounds, 1 part veggie scraps.

The point I'm trying to make is that it really helps to know what you're adding to your pile. It's also worth noting that even your "greens" still have a relatively high C:N ratio. Not that I'm saying to know the C:N of every single thing you throw in... but if you tend to use a lot of the same thing, you ought to know what the C:N is and thus know what kind of balance you're adding to the pile. In your specific case, it sounds like too much "brown" stuff. Paper isn't likely to help your problem. In fact, it will likely make it worse. I'd add some high nitrogen material in. Alfalfa pellets (or rabbit food), are pretty high in nitrogen (close to a 10:1).

Aside from all that... yeah, not keeping it wet enough and not turning it often will also slow things down. It needs to be damp (like a wrung out sponge) and turned often to aerate. The microbes need air or they'll die. Like I said, it could be a combination of all these things. IMO, you should try getting the compost nice and damp, then make sure you're turning it regularly. If after a couple of weeks you aren't getting any heat going in the middle of the pile, or no brownish compost, it's probably time to add some higher Nitrogen material.

Good luck, and don't give up. I also have had to learn the hard way that patience is a virtue... especially in terms of gardening!

Tumblers can be hot or cold, batch or continuous. When you say you've been at it for almost two years, how large is your tumbler and how much material do you generate for it?

I used a 45 gallon tumbler one summer and with continuous feed, it took over 4 months to fill. I only put kitchen scraps from two adults and enough leaves to provide sufficient carbon into it. Never got hot and it worked just fine.

I'd hesitate to say any one thing is the critical factor as composting needs all the parameters to be in tolerance to be successful.

Any pics of your setup?

Lloyd