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Composting – Which Method is Best?

In the last couple of months I have been talking about traditional composting which is also called hot composting. For this method, you pile up the ingredients and keep turning them so the pile gets hot. There are several other types of composting such as bokashi composting, cold composting, vermicomposting, compost tea and making leaf mold. How do these methods compare to traditional composting and do they offer any advantages? In this post I will look at some other options you might want to consider.

Vermicomposting

Vermicomposting

Vermicomposting

Vermicomposting uses a bin, organic material and worms. The worms eat the organic material and produce worm castings ie worm poop. The worm castings are then added to the garden.

Although it is called composting, it is not really a form of composting. It should be called vermidigestion, not vermicomposting. However, the end result is a form of degraded organic matter. How similar is it to compost? I have not been able to find an answer to this question.

Since the process usually takes place in a container, it is suitable for small amounts of organic matter, but I doubt it is very practical for large quantities of yard waste. At least one popular vermicomposting site (ref 1)  does not recommend vermicomposting for yard waste.

The worms need to be kept warm, so in cold climates the warms need to be kept indoors.

I think this might be useful for taking care of kitchen scraps, but wormicomposting does not seem to be suitable for the yard waste produced by gardeners.

Bokashi Composting

Bokashi composting has been discussed before in Bokashi Composting Myths. Bokashi is a way to ferment your kitchen wastes, and even though it is called bokashi composting, it is not a form of composting, . Once the kitchen waste is fermented, the material still needs to be composted using a real composting method.

The process is not suitable for yard waste.

Cold Composting

Cold composting is similar to hot composting. You build a pile of material and then leave it alone. You can turn the pile if you want, which does speed up the process. You can spend time getting the browns and greens just right – but you don’t have to. Basically, you just let the pile sit and rot. It is slower than hot composting but eventually you do get compost. Without getting to a high temperature, weed seeds and diseases are less likely to be killed.

This system works well, is less complicated and less work than hot composting.

I suspect most people who think they are doing hot composting are actually doing a form of cold composting because their piles are not getting hot enough.

Compost Tea

Compost Tea has been discussed before in my blog post called Compost Tea. I have not found any good scientific evidence that shows compost tea is better than compost alone. In any event, the tea is made using finished compost so it is not really a composting process. It is a different way to use compost.

Leaf Mold

Leaf Mold is made by piling up leaves in the fall, and leaving them alone. A cold form of composting takes place. Because the pile only contains browns, there is a shortage of nitrogen. This causes two things to happen. The process is slow, and decomposition is done primarily by fungi, not bacteria.

The result of the process is material very similar to what you get out of a hot compost pile and it is just as good for the garden.

Composting – Which Method is Best?

The best method of composting is the one that you do and continue to do because you like doing it. Any form of composting is better than taking yard waste to the curb.

In a home with no garden, vermicomposting seems to be a good idea that would be worth trying.

If you have a garden, cold composting of yard waste and leaves seems to be the best method presented so far. It is very flexible, and requires little work.

I have tried hot composting and it works. Trying to get high temperatures was too much work for me, so I switched to cold composting. When I moved to my large garden, hauling yard waste over 5 acres was too much work, so I invented the Cut and Drop Composting Method. I think it is the best composting method if your time is a consideration. I’ll discuss this in the next post.

References:

1) Vermicomposting yard waste: http://www.redwormcomposting.com/reader-questions/vermicomposting-yard-wastes/

2) Photo Source: Alfredo Eloisa

Robert Pavlis
Editor of GardenMyths.com
I live in southern Ontario, Canada, zone 5 and have been gardening a long time. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

I hope you find Garden Myths an educational site that helps you understand your garden better.

7 Responses to 'Composting – Which Method is Best?'

  1. Christa avery says:

    Hi Robert – I just found your site – even though I am a fellow Canuck I live in Burma/Myanmar and I am about to have my first backyard garden. I want to hurry and plant before the Monsoons arrive mid June. 2 questions for you:

    1. Is the above true in tropical climates?
    2. What will the monsoon do to my compost?
    3. What can I use in the beginning to help start the compost best before adding leaves?

    Thanks so very much!

    • I have never gardened with monsoons, but the basics of composting do not change. I would expect the warmer climate will make it faster and too much moisture will slow it down.

  2. Debra says:

    My favorite forms of composting are cold composting and leaf mold. (I tend to be a lazy gardener!) But we’ve recently started using a large worm bin inside our unheated hoop house – about 3’x4’x18″ high. The worms survived temps as low as 14 F inside the hoop house, though it doesn’t usually drop below 20 F at night.

    We use shredded leaves and grass cuttings as bedding, and add our kitchen scraps and smaller veggie garden debris to feed the worms. We harvested 50 gallons of worm castings this spring. From my research, it seems that worm castings are as good or better than regular compost, but should be limited to no more than 10-15% of potting soil. That amount produced the most vigorous plant growth.

    • Why would worm castings be better tan compost?? The degree of decomposition may be different in the two sources – worms might cause faster decomposition. But if you think about the two systems. I put a carrot into each system. The carrot has a certain amount of nutrients – you can measure the amount of nitrogen, phosphorus etc. In each system the carrot is degraded – but you still have the same nutrients present.

      There is one possible exception. Nitrogen. Nitrogen can be converted to forms that escape into the air. So one form of composting may end up with more or less nitrogen. I’d expect this difference to be minor, since both compost and worm castings are only partially decomposed organics. Much of the nitrogen is still in organic forms which would not be lost to the air.

      • Debra says:

        Here’s one study conducted at Cornell University, comparing the growth of tomato seedlings in various potting mixes. Please note the large difference between potting soil using thermophilic compost versus vermicompost – both produced from the exact same ingredients, except for the worms.

        http://www.wormpower.net/wp-content/uploads/2014/04/Organic-Transplant-Media-and-Tomato-Performance-2007.pdf

        It could be that the worms convert the nutrients into a form that is more readily used by the plants. Also, vermicompost has a rich population of soil microorganisms, including mycorrhizal fungi – a population that is often very different from thermophilic compost. It could be that that particular population of beneficial soil organisms encourages more vigorous and healthy growth in plants.

        I’m not a vermicompost fanatic, but I’ve read several studies showing similar differences. This is just one study that I found the soonest for your reference.

        • Interesting study. Is your comment “please note the large difference between potting soil using thermophilic compost versus vermicompost – both produced from the exact same ingredients” correct?

          The study did compare Diary Thermogenic compost 20% (v/v) with Dairy vermicompost 20% (v/v). Both of these were made from the same dairy manure. The dry weight of plant material grown in the Thermogenic compost was 0.11g vs 0.49g for vermicompost. So clearly the plants were bigger with vermicompost. At first glance your comment seems to be correct.

          Here are some issues:
          1) This was done in a lab. Results in a lab can be very instructional, and can suggest further testing, but they can’t be extrapolated to the field. The testing did show that vermicompost added to the peat based soil they tested worked better in pots. It did not show it will work better in a garden or farm condition.

          2) The report lacks a lot of the details on how the test was done making it hard to really understand the results. In fact the conclusion you suggested is not a conclusion reach by the scientists doing the study. I wonder why?

          3) Plants were grown for less than a month before the first plant was weighed, and 1.5 months for the final weighing. How do the soils affect the tomato plant long term? Which soil produced the most fruit? The largest fruit? As a gardener I don’t really care about seedling growth – I care about tomato production.

          4) The vermicompost soil started out with almost twice as much nitrogen in plant available form. It is not too surprising that the seedlings grew faster with the extra nitrogen – the main conclusion of the study where blood meal added more nitrogen. The total nitrogen for the two mixes was about the same. Which seems to indicate the nitrogen in the Thermogenic compost was less digested, which means that it might produce better long term growth as a result of a slower nitrogen release. This study did not look at this.

          5) The plant material weighted was just the growth above soil level. Odd that they did not look at root growth. Early root growth in tomatoes can result in more fruit production later on. We don’t know which mix produced better roots.

          6) Your original statement assumes that the amount of the two composts is identical in both of the mixes we are discussing, and on the surface it would appear to be the case. However, there is a small piece missing in the study. The mixes were made with 20% (v/v) of either Thermogenic compost, or vermicompost. But what happens as the worms digest the starting manure? Lets say we start with 100 g of manure. How much do we have at the end of vermicomposting? How much do we have at the end of the Thermogenic composting process? If these weights are not identical, then the amount of ‘starting material’ in the two mixes was not the same. The study did not try to establish these numbers. For this reason, it is difficult to reach any certain conclusion about the comparison of the two mixes.

          I agree the study seems to indicate that vermicompost is as good as, and probably better than compost for seedling growth. What the study does not show is that it is better for producing tomatoes, and it shows nothing about it’s comparative value in the field.

          Thanks very much for posting the reference.

          • Debra says:

            Thanks for your detailed analysis of the study. That was helpful, and you made a lot of very valid points. I suspect there may not be many field studies for long-term effects of vermicompost, simply due to the higher cost of the large volume needed to amend the topsoil in gardens or farms.

            I’m quite happy knowing that it’s an effective product to help produce large, vigorous transplants. That’s mostly how I use my own vermicompost. It doesn’t matter to me if the thermophilic compost might provide nutrients over a longer period of time, because my plants will be in the ground by then.

            But I would have loved to find out how the root growth compared between the two. I agree about the importance of good early root development. That’s one reason why I prefer to start my seedlings in larger than normal containers, so they have a chance to develop a larger root system before transplanting. I’ve discovered that seedlings started in larger containers grow much more vigorously when planted outside, and often produce higher yields.

            Thanks again for your thoughtful comments.

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