Story last updated at 8/22/2012 - 2:13 pm
Compost is simply decayed organic matter created for fertilizer from waste materials like kitchen scraps, old stalks and leaves. Composting is a great way to recycle and the final product is an excellent natural fertilizer, as rich and fertile as manure with added benefits.
In the compost heap, naturally occurring microbes process the energy and nutrients tied up in the cells of decaying organic matter and release them. Added to your garden compost will increase the percentage of humus (organic component of soil) and help feed the billions of microorganisms that generate soluble compounds absorbed by plant roots. When developing and improving the dirt we find in Southeast Alaska, the addition of compost improves drainage and soil structure while slowly releasing nutrients for our garden plants.
Composting can be as simple as throwing organic matter on an open pile or can be more organized with a container made of materials such as wire, slatted boards or concrete blocks as long as air can flow through. Hand cranked tumblers or barrels that can be rolled are also good choices, depending on how you want to go about it. I use old pallets tied together with twine to shape my compost boxes. Two or three boxes are best so that the contents can be periodically turned over into an empty box.
Layered properly, the different kinds of materials - dry leaves, straw, sawdust, cardboard, grass, seaweed, kitchen scraps - will undergo microbial breakdown and generate heat. Decomposition occurs naturally with adequate moisture and oxygen. Microbes, not the sun, heat compost. Temperatures and decomposition rates can be controlled by the ratio of carbon to nitrogen materials, size of the materials (chopped up or left whole) and frequency of turning the heap. At least 10 times more carbon (leaves, straw, organic matter) than nitrogen (grass, food scraps, weeds) is recommended.
Compost made the slow, passive way (simply piling unchopped materials and leaving them to decompose) is reported to create a more disease resistant result than compost made by the faster hot method but they can be combined for a good compromise.
Another type of composting, vermiculture, involves composting with worms. This can be done indoors in small systems or outside in combination with the compost heap for a fabulous mixture of worm castings and compost. My bottomless compost bins which are placed on the ground, attracted red worms that soon developed a huge population among the aged sawdust, cardboard, kitchen scraps and grass clippings. They are free to retire underground when freezing temperatures prevail and have maintained a strong presence over the years.
Since I don't chop or turn my compost heap often, the activities of the worms and natural, passive decomposition are mainly converting everything to humus although temperatures inside fresh grass clippings have been quite hot so many factors are at work. The red worms apparently move around in the pile as temperatures permit and it all works together to provide about 10-15, five gallon buckets of granular, fresh smelling compost each year. The red worms multiply rapidly as one adult may produce 150 offspring per year. Hard to imagine in human terms just naming them all, but it's great for our gardens.
Comfrey, a plant I cultivate just for compost, is an excellent source of potassium among other nutritional benefits. Growing very quickly, comfrey can be harvested several times through the summer, chopping off its fuzzy, broad leaves at a couple inches above the ground. Once established, however, comfrey is very difficult to eradicate so care should be given when choosing a site to plant it. Beautiful in bloom, the plant's bell-shaped, purplish flowers attract numerous bees.
Around March when my compost heap is workable, I turn over the decomposing material into another bin and run the finished compost on the bottom through a metal grate to sift out any large, still decomposing parts. An old metal bathtub, although not particularly adding to the aesthetic beauty of my back yard, is just the right size for the screen I use. I try to put as many red worms as possible back into the compost bins since that type of worm is not found in my garden beds where big night crawlers are at home. I then work the compost into the top of the dirt as I prepare the beds for the new growing season.
Although there's much room for improvement in my operation, it's nice to know a few simple steps to recycle can be so easy and work so well in Southeast Alaska's temperate rainforest climate. It's really easy to create your own organic fertilizer.