Tumbler Home Composting - Ask Extension
I enjoyed viewing your "Compost Can-do: Develop A System That Meets Your Needs" video (2022 MG Level-up Series). I still have a few questio...
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Tumbler Home Composting #855840
Asked November 28, 2023, 12:29 PM EST
I enjoyed viewing your "Compost Can-do: Develop A System That Meets Your Needs" video (2022 MG Level-up Series). I still have a few questions about composting. Now that it is winter, there is no rush for answers. Related to my questions, I will provide some background, then ask the questions.
Background:
I am a newly certified Oregon Master Gardener from Central Oregon and a member of COMGA.
My goal is to start "scientifically" and safely composting my home and backyard "greens and browns."
I recently purchased a Large Dual Chamber Compost Bin Tumbler (2 chambers × 18.5 Gallon (70 liters) each). I bought the tumbler to facilitate easy aeration and to put less stress on my back. The Tumbler will be placed outside near my garden boxes and be subject to Central Oregon weather, (cold winters, sometimes warm summers).
I also have a strong Environmental interest and would like to educate others on the benefits of home composting.
I would welcome your references to vetted publications, accessible via the internet. Although I have advanced degrees, my educational background has been in business and physical therapy. Technical articles in horticulture, agricultural science, botany, etc. are sometimes beyond my understanding.
Questions:
1. I am still confused about the mixture of "Greens" to "Browns". What ratio do you recommend? In mixing the greens and browns, do you use weight as the measurement? Since the "Greens" contain water, how does one figure out how much additional water to add to the mixture? In converting measures like liters or gallons to pounds, do you use "water" (1 liter (l) = 2.204622622 pounds) as the conversion unit ?
2. I would like to use my Tumbler in the winter, though I won't use it this winter (2023-2024). I will start using the Tumbler in spring (2024) and would like to then continue its use through the winter (2024-2025). Do you think this is feasible? I don't wish to mess with adding any protective winterizing insulation to the Tumbler.
3. I am confused about managing the time period for composting when making small additions of raw material to the Tumbler. Are there easy ways to judge when the compost has been properly "cooked" and is ready to be taken out of the Tumbler and mixed in with my vegetable garden beds? How do I factor in outside temperature variations?
For example, over the Central Oregon winter, my additions of household waste "greens" will be about 6.6 L every 2 weeks. Mixing at a ratio of 1:2 (figuratively...I still wish to know the proper ratio), it will take approximately 6 weeks to partially fill one of my tumblers (59.4 L of greens and browns, Calculation: 6.6L x 3 placed in Tumbler every 2 weeks x 3 occurrences). Any suggestions on how long it will take to achieve good compost once the Tumbler is filled, will be most helpful.
4. Lastly, with my interests in combating climate change, I would like to convert people into adopting, when practical and safe, a home composting routine. Have you seen any good articles that provide a "how to" for the busy, small home/apartment dweller that may want to help the environment with home composting; but, may not have the space to use all the compost generated (i.e.may not be a gardener)?
Deschutes County Oregon
Expert Response
Hi, Michael Reed:
Thanks for your questions. The most important thing here is NOT TO OVERTHINK THE PROCESS. Decomposition goes on in the world all the time without being too "scientific" about it. I firmly believe that everyone who wants to compost will hit on the right technique for their physical capabilities and their climate - you try one thing, and if that doesn't work out, you tweak your technique. Now to your questions, by the numbers:
Greens:Browns 1 part by volume of greens (including kitchen scraps) to 3 or 4 parts by volume of browns. If it draws flies or liquid drips from the tumbler, add more browns. If it fails to advance significantly (materials darken and begin to lose their identifiable characteristics) add more greens. Your best bet is to add grass clippings or kitchen scraps, as they are high in water content, but it's water that is released 1 molecule at a time, as the materials decompose. If you must add water from the end of a hose, it's best if you provide a spray of fine droplets. I have never made a calculation about adding water, including when I was conducting laboratory-based research.
Winter Tumblers: You're wise not to start this venture this winter. Get a sense of how the process works before you take on the challenge of sub-freezing temperatures. No, I don't see any sense in trying to insulate the tumbler, but you might consider building a wall of straw bales to protect it from prevailing winds. For that matter, that protection might provide protection during the growing season from drying winds if space allows.
Time to Completion: Don't try to be too predictive here, Mike. Compost is done when it's done. It will be dark, and not smell like ammonia or feces (anaerobic). You won't be able to recognize most of the starting materials. I'm not beyond pulling a few avocado or orange peels out and running them through again if the rest of the compost looks ready to me.
Time to completion is based on adequate (but not too much) water and nitrogen. If you have an irrigated lawn, you might get enough N in grass clippings. You can also dissolve conventional fertilizer in water (say 1 C per 5 gallons water) and add it. Personally, I keep a 40 lb bag of alfalfa pellets on hand for N. Spray them with a little water to cause them to begin to fall apart, and let bacterial action do the rest.
Converting others: Mike, I think the best plan is for you to get your process down. When you can speak from your own experience, look for opportunities through your local chapter to share information with others (County Fair, perhaps?) Here's the link to a search I just conducted in the OSU Extension Catalog: https://extension.oregonstate.edu/catalog/new-releases?combine=compost
You can find a lot of stuff on the internet, and I've been known to be interviewed by the New York Times and MarthaStewart.com, but a lot of what's out there is dubious.
Thanks for your questions. The most important thing here is NOT TO OVERTHINK THE PROCESS. Decomposition goes on in the world all the time without being too "scientific" about it. I firmly believe that everyone who wants to compost will hit on the right technique for their physical capabilities and their climate - you try one thing, and if that doesn't work out, you tweak your technique. Now to your questions, by the numbers:
Greens:Browns 1 part by volume of greens (including kitchen scraps) to 3 or 4 parts by volume of browns. If it draws flies or liquid drips from the tumbler, add more browns. If it fails to advance significantly (materials darken and begin to lose their identifiable characteristics) add more greens. Your best bet is to add grass clippings or kitchen scraps, as they are high in water content, but it's water that is released 1 molecule at a time, as the materials decompose. If you must add water from the end of a hose, it's best if you provide a spray of fine droplets. I have never made a calculation about adding water, including when I was conducting laboratory-based research.
Winter Tumblers: You're wise not to start this venture this winter. Get a sense of how the process works before you take on the challenge of sub-freezing temperatures. No, I don't see any sense in trying to insulate the tumbler, but you might consider building a wall of straw bales to protect it from prevailing winds. For that matter, that protection might provide protection during the growing season from drying winds if space allows.
Time to Completion: Don't try to be too predictive here, Mike. Compost is done when it's done. It will be dark, and not smell like ammonia or feces (anaerobic). You won't be able to recognize most of the starting materials. I'm not beyond pulling a few avocado or orange peels out and running them through again if the rest of the compost looks ready to me.
Time to completion is based on adequate (but not too much) water and nitrogen. If you have an irrigated lawn, you might get enough N in grass clippings. You can also dissolve conventional fertilizer in water (say 1 C per 5 gallons water) and add it. Personally, I keep a 40 lb bag of alfalfa pellets on hand for N. Spray them with a little water to cause them to begin to fall apart, and let bacterial action do the rest.
Converting others: Mike, I think the best plan is for you to get your process down. When you can speak from your own experience, look for opportunities through your local chapter to share information with others (County Fair, perhaps?) Here's the link to a search I just conducted in the OSU Extension Catalog: https://extension.oregonstate.edu/catalog/new-releases?combine=compost
You can find a lot of stuff on the internet, and I've been known to be interviewed by the New York Times and MarthaStewart.com, but a lot of what's out there is dubious.
