All compost is not created equal. Compost higher in nitrogen is sometimes called green compost, while higher-carbon compost may be called brown compost. There is also worm compost and compost tea. Let’s take a look at how one common compost feedstock – shredded leaves – can end up in four end products: brown compost, green compost, worm compost and compost tea.
There are too many leaves that fall from the trees around my property to feed my regular compost pile, where I mix leaves with “greens,” compost materials that are higher in nitrogen. So I keep several leaf heaps, piled as inconspicuously as possible along the woods. I use the shredded leaves as mulch along perennial beds; borders between our yard and the woods; even on paths and trails. Using leaves and other “browns” as mulch is one of the simplest compost methods – and one of the easiest ways to keep yard wastes out of the solid waste stream.
I like to use leaves from older piles to either feed my composter or as mulch in beds. A leaf pile does start decomposing over time. The more decomposed the shredded leaves, the less likely they may be to draw on nitrogen available in the soil to continue decomposition. An inch or two of shredded leaves provides mulch which is both ideal and economical. All it costs is the exercise you get moving the mulch around.
“Green” compost is not the color green; it is higher-nitrogen compost. This is the compost coming from your own composter, heap or local source where higher-nitrogen materials (grass and plant trimmings, animal manure, coffee grounds) have mixed and decomposed with high-carbon
sources (like shredded leaves). The nitrogen and nutrients in green compost make it a wonderful amendment to flower and vegetable garden soil.
Worm compost is an altogether different critter. Red worms that continually feed on organic wastes worms eventually leave behind worm castings, called “vermicompost.” It is a dark, rich material which may be used to for starting seeds and potting houseplants.
Compost tea is made by putting finished green compost into a burlap or cheesecloth “compost teabag” and left to soak in a bucket of water. Nutrients leach out of the compost into the water, and the water may then be used to fertigate (fertilize and irrigate) plants. It is just another way the plants around your home and garden can benefit from compost.