Well I'm something a n00bie in the compost world but my opinion would be if you have room in your tumbler then go ahead and add more greens and see if you can get it to heat up.

If you add a bunch of greens, you'll be restarting the compost cycle. I don't expect that a few greens will make a significant change. You'll have to add a bunch of grass clippings or a big bag of coffee grounds from Starbucks.

Yes, much better to toss lettuce leaves and coffee grounds in the compost tumbler rather than in the trash, much better! :-) The lettuce will break down fairly quickly and the UCG will help with heating.

Do you think you had a pretty good mix of greens and browns to start with? If it's not heating you may have to continue to add greens. Coffee grounds are a good altho mild source so you may have to add a lot as previous poster said.

My problem with my compost is that it's almost all greens and didn't do any crazy cooking. What did you put into it to begin with?

Alicev,
I think that it is ok to keep on adding to your compost tumbler until you are ready to "harvest" it. That is what I do and what I've been doing for a long time. If I have any uncomposted materials in the finished compost, I just put it back into the tumbler and start the process all over again. I have written an article that I think will answer a lot of your questions. It is posted down below.

Here is a link that might be useful: How to Use the Original Compost Tumbler

I'm not sure it will add a lot to the heat potential but adding soft, easily degradable stuff like UCGs, lettuce, banana peels etc is fine. It seems these materials disappear very quickly in the tumblers for me. It's them pesky egg shells and onion skins that seem to hang around a long time.

Lloyd

P.S. Beth, I like your article.

The weather has little to do with whether a compost pile heats up or not, it is the ratio of Carbon to Nitrogen (the C:N ratio) that provides the bacteria that digest that material with a food source. If a pile of material does not heat up there is usually two reasons, not enough Nitrogen (greens) or too much moisture. Adding greens (both Nitrogen and moisture) may or may not help if they also increase an already too high moisture level.
Look closely at the mix you have to determine if it might be too wet, or if you might need to add more Nitrogen.

fill that thing up with horse manure and bedding, than start slicing buckets of greens in with the edging shovel, turn, turn, and keep chopping/ slicing with the shovel. add fresh material in the middle of the batch by creating a hole with the (edging shovel). youll be off to the races in a couple of days.

ron

ron

One of the problem with tumblers is that they totally destroy fungi. Bacteria based compost is ok for veggi gardens but are not as beneficial to perenials. I will clarify that any compost is going add nutrients to the soil, but the constant turning of the tumbler will totally destroy the long thread-like structure of fungi. So, if you are hoping to use compost from your tumbler for anything other than your veggi garden you will not be doing as much good as you think. You see bacteria reproduce very fast and have a much shorter lifespan than do fungi. Annuals, like veggies, have developed a strong symbiotic relationship with bacteria because bacteria better suit their life cycle. Prenials, on the other hand, have a strong preference for fungi. Fungi live for yars and prenials have developed a strong preference for fungi. Have you ever left a complst pile alone for several months and then when you turned it you saw a lot of white threads running through the pile? These are the fungi that have established themselves in the pile. They are very beneficial to both annuals and perenials. By turing the pile you destroy them. Again, this is not a big deal if your compost is destined for the veggie garden. Although if you are growing artichokes or asparagus you might want to reconsider adding compost that has a good amount of fungi.

Alicev said, "I think that it is ok to keep on adding to your compost tumbler until you are ready to "harvest" it." You need to be careful here. You should never mix uncomposted material into the garden soil. If you do the microbes in the soil will have to finish the job that you started. Since you will not be adding a lot of food (energy) to the soil for the microbes theyt will take the food you intended for your plants in order to finish the job you started. If you are putting raw material into the composter to late in the process then there will be a lot of partially composted manerial mixed in with fully composted stuff. It is best to accumulate your ingredients for a batch of compost and then at some point stop adding material until that current batch is fully composted. Now, If you are going to use the compost as mulch then this whole discussion is moot. Mulches compost in a static (cold) form of composting - a process that is totally different than what we do in hot composting. In static composting only the material that is in direct contact with the soil decomposes, resulting in a slow process that occurs from the bottom up. This is the process our forests use. It is very different than hot composting. If you put raw material into the garden bed you will get the microbes so stimulated trying to break down the partialy decompsed material that you will actually upset the natrual order of what has been established.

Lets be very clear here. You cannot make finished compost in two weeks - I don't care what any commercial advertisement states. Any commercial compost bin manuracturer (tumbler or otherwise) who says they can is lying - not opinion but fact. You can create enough heat to darken the outside of the material to make it appear to look like fished compost but you will actually have material that is just as raw and green as the day it was put in the bin. I don't care if you are using the perfect carbon/nitrogen ratio with the optimal level of moisture, etc, etc, etc,; the physics just do not allow the tumbler to make finshed compost in two weeks because the pile inside the tumbler is simply not big enough. Not opinion but fact. I have been composting for years and I seldom get the "perfect" mix, well lets just say, not as often as I would like. If it sounds to good to be true then it probobly is.

Tom

I'm not sure I buy the claim that tumblers totally destroy the fungi. I don't think they are that fragile. If they were, then the mere action of digging up any compost pile and transporting it would also be detrimental. These things have apparently been around a long time and will outlast mankind in the end.

I also think that within hours of mixing compost (or any organic material for that matter) into the soil, the fungus begins it's process. Once again I don't think we as humans have to do anything. If there is food, water, and oxygen, the fungi and microbes will come.

And I agree, two weeks to achieve my definition of completely finished compost is bogus. But I can get compost past the thermophyllic stage in two weeks and let the curing pile/bin handle it from there.

Lloyd

P.S. Not all tumblers are small.

P.P.S Sorry for getting off topic again!

It is not that moving or turing a pile occasionally destroys all the fungi, it is that those who tumble their compost typiclaly tumble their pile multiples of times more often than do those who compost not using a tumbler. It is the constant tumbling that is so harmful to the fungi. I will turn my pile five times, or so, during the entire process of composting. Those who use a tumbler will turn their pile as many times in a week.

Tumblers make great compost, the finished product is just more geared to bactria than fungi. For those who do not have a large area to do different kinds of composting tumblers make a lot of sense - even perfect.

It is true that not all tumblers are small. But how many tumblers that are bought by home gardeners would be considered big?

Tom

I am not arguing that tumbler composters are not good. My comments were about their effects on fungi and adding raw materials to the compost too long into the process.

Fungi are not an important component of the compost process, in your soil in your garden they are, but not in the composting process. What are going to digest that material would be bacteria, not fungi. As the bacteria work at digesting that material, and generate heat while doing that any fungi would be destroyed by that heat.

From Cornell Composting

"In compost, fungi are important because they break down tough debris, enabling bacteria to continue the decomposition process once most of the cellulose has been exhausted."

Lloyd

Here is a link that might be useful: Cornell Compsoting

Fungi are not vital for the composting in this topic. If you have a pile of sticks, yeah. If you are careful not to add all that, then no. Fungal based compost systems are expected to take between a year and 3 years to complete the process and are not supposed to be turned nearly as often in order to allow the hyphae strands to continue to form so that the fungi spread. If you are using a tumbler, your goal is usually not to use a fungal based system. So, no, fungi are not important in compost in this topic. Not while actually in the tumbler.

It does bring up a point I think some overlook, though. Just because you have woody matter not broken down, that doesn't mean you shouldn't use the compost. Don't wait for fungus to break down cellulose of woody plants. You can sift it out if you care to. I do. Then add the chunks to a pile to sit and "cure" with fungus or use it as worm bin bedding (which is what I do). If you choose not to sift, just add it to the garden and fungus will establish just like fungi under a wood mulch.

I know that was following a tangent, but I think the actual question was answered well enough. Did anyone mention adding blood meal or fertilizer to the mix? Those help and are recommended by many extensions.

I have a question: What is the goal of your composting? If it is for gardening, you can add to a point, but you need to stop adding to it when it's full and just let it compost for the reasons already said. But, if you are doing it for waste stream reduction, then you don't have to be so stringent. Your goal can certainly determine your methods.

From the Institute of Cell and Molecular Biology, The University of Edinburgh

"At this stage, a second group of thermophilic fungi start to grow (c in Fig. E). These fungi include Chaetomium thermophile, Humicola insolens, Humicola (Thermomyces) lanuginosus (Figure G), Thermoascus aurantiacus (Figure H), a Paecilomyces-like fungus (Figure I) and Aspergillus fumigatus (Figure J). By their combined activities, these fungi bring about a major phase of decomposition of plant cell-wall materials such as cellulose and hemicelluloses, so that the dry weight of the compost can be halved during the relatively high temperature phase lasting 20 days or more after peak heating."

"This fungus can grow at temperatures ranging from 12o to about 52-55o. Strictly speaking, it is not a thermophile because its temperature optimum is below 50o, but it is a very common and important member of the high-temperature compost community."

Fungi ain't just for sticks and wood. All I'm trying to say is that composting is more than single entities working by themselves. It's a team so to speak. It's not 'just water', it's not 'just air', it's not 'just carbon', it's not 'just nitrogen', it's not 'just bacteria' and it's not 'just fungi'. It's all of them together.

Lloyd