Composting Basics - Methods And Types Of Composting
In a hot compost pile, the temperature reaches between 60-70°C (140-155°F). The heat is generated by microbes breaking down the organic matter. A hot compost needs to be quite large to work well. You will need a minimum of 1 cubic meter of materials, ideally more. The microbes need a lot of oxygen to do their job well. That's why you have to turn a hot compost heap regularly. When you turn it, the outside is worked into the middle of the pile so everything breaks down evenly.
Advantages And Disadvantages Of A Hot Compost Pile
- produces large quantities of high-quality compost in a short period of time
- weed seeds and perennial weeds get killed in a hot pile
- the ideal method if you have a lot of organic material available
- often not suitable in small gardens because of lack of materials and space required
- needs frequent turning to work well
- experience and skill required to get it right
This is the preferred composting method for most home gardeners. It is easier and less cumbersome than hot composting but it needs more time for breaking down. Depending on the used materials and your climate it can take 8-12 months before it is ready. Most heaps do fine with being turned only once or not at all.
Advantages And Disadvantages Of A Cold Compost Pile
- easier and less labor intensive
- works ok even on a smaller scale
- needs a long time before it is ready
- weed seeds and perennial weeds don't get killed off so be careful what you put in your pile!
Vermicomposting (Worm Composting)
This method can be scaled to nearly any need and size even if you don't have a garden. You can do this in a small bin on a patio, balcony, basement or a garage. Kitchen scraps and other organic wastes are broken down by compost worms (usually Red Wrigglers). The finished worm castings are very fertile and can be mixed into potting soil, garden beds, and plant containers.
Advantages And Disadvantages Of Vermicomposting
- can be done on a small scale
- an ideal way to turn organic waste into valuable fertilizer for apartment and balcony gardeners
- the liquid running off the bottom of the worm farm (worm juice) can also be used as a liquid fertilizer
- probably the best way if you don't have a big supply of organic waste
- seeds don't die off (so might end up with a lot of free tomato plants where you don't want them)
- lemon and orange peels can't be put in a worm farm as they kill the worms (as we learned the hard way)
- not suitable for coarse organic material i.e. stalks of larger plants etc.
How To Make Garden Compost
Composting Basics - Get Your Organic Materials Ready
Composting is a bit like cooking...the end product depends a lot on the quality of the ingredients that go into it. For a good pile, you need what is termed as green and brown materials.
Green materials contain more Nitrogen which the microorganisms need to build up. Green materials are for example grass clippings, kitchen scraps, green crop wastes, comfrey and nettle leaves, or young weeds (no seeds!). A heap with low Nitrogen will break down very slowly.
Brown materials contain more carbon which is needed to form stable humus colloids. Brown materials are e.g. fallen leaves, straw, shredded clippings from trees and shrubs, cardboard and paper.
The ratio between carbon to Nitrogen should be 25:1. I know...this ratio does not mean much for most of us.
I will try to make it easier for you. Mix 2 parts of your green materials with one part of the brown organic waste and sprinkle a bit of good garden soil (about 5% of the finished heap). The soil is a great innoculant as it contains all the necessary microorganisms needed. This should give your heap a good start.
weeds (no seeds)
green crop wastes
shredded garden clippings
paper (not the glossy stuff!)
Composting Basics: How To Build A Compost Pile
Choose a spot that will be shaded to prevent the pile from drying out. Layer some coarse material like stems from plants at the base to allow oxygen to get in from the base. Make the pile big enough ...it should be minimum 1 m x 1 m (1.5m x 1.2 m would be better if you have enough material). Aim for 1-1.2 m high. You can layer the brown and green materials. Make sure that everything is moist but not soaking wet.
An insulation layer of straw is a good idea to keep the temperature in the pile even and to prevent freezing in the winter.
Do you want to learn more about making just the perfect compost for your garden? Here are our book recommendations on composting basics: