Introduction
One of the questions that I am frequently asked, is “What type of Compost do I need for a Compost Tea Brewer?”. In this article I will discuss the different types of Compost, and how to use them to maximise the potential of your Compost Tea Brewer.
Compost Quality
The first thing to explain is that the quality of your Compost Tea brew, depends on the quality of the Compost that you use. No matter how efficient your Compost Tea Brewer is, if the microbes are not present in the Compost, they won’t be in the Compost Tea. So you need to make good compost to get the most out of your Compost Tea Brewer.
The material out of which your compost is made, and the method that you use, will also effect the type of microbes present in the Compost. Most articles explaining how to make Compost tell you to use a mixture of High carbon (Browns) materials, with high Nitrogen (Greens) materials. This is to help create the conditions for thermophilic bacteria to operate (hot composting). This might not actually be the best solution for Compost Tea. My own reading, and experience, suggests that Vermicompost (Worm Compost), and Leaf Mould, probably have the highest levels of beneficial microbes. Whilst worm compost tends to be bacterial dominated, and leaf mould tends to be fungal dominated, what they both have in common is that they are both cold composting methods.
Cold Composting
Most people recommend hot composting, as when it is made correctly, the heat generated by the thermophilic (heat generating) bacteria kill off many of the pathogens, and weed seeds. I believe that this is not so important with Compost which is going to be used in a Compost Tea Brewer, especially if the Compost is put into a suitable filter (400 microns is ideal). I don’t know of many weed seeds that are going to sneak through a mesh size of less then half a millimetre, and any pathogens present in the compost should be out competed by the beneficial microbes during the Compost Tea brewing process. The downside of cold composting is that it takes time, but the upside is that it takes less physical effort.
Compost Materials
Most of the material used in Compost heaps is grass based, such as grass clippings and straw, or ’soft’ vegetable matter, like vegetable peelings, and annual weeds from the garden. These are principally broken down (eaten) by bacteria. The woodier materials, including leaves, tree prunings, and bark are broken down by fungi. To get good levels of both, you need to use both types of material. However we can keep them separate. If we make leaf mould with our leaves, and build a large wormery for the green materials, we can produce two different composts for two different purposes. That’s not to say that you shouldn’t add ‘green’ waste to your leaf mould, or leaves to your cold compost heap, but we’re not looking to add too much, and certainly not enough to produce lots of heat. Then, if we want a fungal dominated Compost Tea Brew, we use primarily leaf mould. If we want a bacterial dominated brew, we use predominately Vermicompost, and if we want a mixed Compost Tea Brew we have three options. Start with leaf mould, then add the Vermicompost after 24 hours. Mix the leaf mould and Vermicompost at the start of the Compost Tea Brewing process, but keep the bacterial nutrients (molasses) out of the Compost tea Brewer until about 12 hours before application. Make two separate Compost Tea brews, and mix them prior to application. Of the three, I prefer to make two seperate brews, as this gives me the most flexibility. I can use either type of brew, or combine the two. It does mean that you need two Compost Tea Brewers though, so for most people the second option is probably the best.
Getting Started
As Cold Composting takes longer than Hot Composting, we need to cheat a little to get ourselves started. Here are some ideas.
One of the best cheats is to buy some Vermicompost from a worm breeder. Here in the UK, most worm breeders do so to sell worms as fishing bait. Keep your eyes open for signs advertising worms for sale, and then go in and ask to buy some worm castings (Vermicompost), and some Worms. Make sure that the worms that you buy are composting worms. When you get home split the castings into two. Use one lot to start off your own wormery, using the worms that you bought, and use the other to create ‘ready to use’ compost mix. This is how I started my own wormeries. The best bedding material for worms, are their own castings, as the castings contain all of the microbes that the worms need. It gives them a head start. A really good book on the subject is Composting With Worms by George Pilkington. This link tells you about the book.
http://www.eco-logicbooks.com/index.cfm?fa=book_details&book_id=984
Some worm breeders, producing worms for fishing bait, get left with quite a lot of Vermicompost, and sell it reasonably cheaply. Buy as much as you have room for.
Making Leaf Mould is a slow process, sometimes taking two years to complete. In order to speed the process up a little there are some things that you can do. Firstly you should shred all of the leaves. The easiest way to do this is to lay them out in rows, and go over them with a lawnmower, collecting them at the same time. The shredding increases the speed at which the fungi break them down. The heaps should be kept moist, but not turned. too much turning and aeration can harm fungi. You can add some nitrogenous material, either grass clippings, or urine. Both are effective. Probably the best method is to add good soil, preferably a clay based soil, to the heaps. This really seems to speed up the process, and it was an idea that I got from my research. Here are two links that discuss the use of clay to aid humus formation. They are a bit technical, but might be of interest to you.
http://mailman.cloudnet.com/pipermail/compost/2004-February/011737.html
http://www.ibiblio.org/steved/Luebke/Luebke-compost2.html
It is best to take the soil from ground that has not had much disturbance (digging/ploughing) and has a high humus content. If you already garden organically, particularly no-dig gardening, your own vegetable beds will be a great place to take some topsoil from.
Another way to speed things up, and get some really good fungi into the heaps is to collect some leaf litter from a well established woodland. I’m not saying that you need to take a bulldozer and scrape up a couple of tons, but a little here and there from as many different woods as you can, will get you a really good mix of fungi. Add some of this to your leaf mould heaps, and keep some for your first Compost Tea Brews.
Mixing and Matching
Once your heaps are going, you can move microbes from one heap to another simply by making a Compost Tea Brew, and then spraying some of the Compost Tea onto your various Compost heaps. This is a great way to get the composting process started, and it also speeds up the breakdown of materials, and increases worm activity in the heap. What’s really great is that all of the compost left in the filter at the end of the Compost Tea Brewing, can be put back into the heap. it’s still full of microbes.
Hot Composting
I don’t have anything against hot composting, particularly for producing Compost for my vegetable beds. My concern is that the high temperatures may be harming some of the beneficial microbes. With my Compost Tea, I don’t want to take any chances that I might be reducing the effectiveness of the Compost Tea.
I hope that this article has been of use to you, and I would be happy to answer any questions that you have, so please feel free to ask them, by posting a Comment.
BB
P.S. Check out the Sustainable Smallholding Website…
