Thanks to Seattle Tilth’s Master Composters Ruth Ihlenfeldt and Michelle Brennan, we learned how to make our Pea Patch composting system more efficient, so that it yields compost in three months rather than two years. Below is a summary of what it takes to create and maintain a compost pile, with photos by Janet Horton, who is a professional photographer as well as a PeaPatcher.
1. Plan for a balanced diet of green and brown. We stash bags of maple leaves behind the compost bins in the fall, so we can use them in the spring and summer. Mulching them with a mower first would be even better.
2. Accumulate succulent “greens” in the designated bin, cutting materials into one-inch pieces or smaller.
“Greens” include grass clippings (no herbicides or pesticides!), weeds that haven’t gone to seed (no buttercup or blackberry roots), manures, coffee grounds, and non-diseased garden vegetable leaves, stalks and fallen fruit. Starbucks packages up coffee grounds daily and offers them to gardeners.Woman cutting up garden waste for composting
Be sure to cut up stalks and roots into pieces no longer than one inch using hand pruners and loppers available in the shed for everyone to use. It only takes a few minutes to do this as part of your garden routine. Decomposers can break down small pieces faster than large ones; otherwise, kale and broccoli stems still aren’t broken down after two years.
3. When ready to build a hot pile, mix equal volumes of chopped greens and browns. In our case, we mixed accumulated vegetable waste, grass clippings, coffee grounds, and two scoops of manure in a 5-gallon bucket. And then we dumped that simultaneously with 5-gallon bucket full of browns (maple leaves) into a ~15-gallon tub.
4. Stir to thoroughly mix greens and browns.
5. Sprinkle with water until the mixture is as wet as a wrung-out sponge.
6. Add the moist, mixed mess to the compost bin. Repeat until the bin is full.
7. Cover with a tarp to retain moisture, and so rain doesn’t wash out nutrients. Allow to cook for about a week, monitoring the temperature with a compost thermometer. Ideally the center of the pile reaches 110°—140°F (130° is hoCompost pile with large piecest enough to kill weed seeds—too hot to touch!).
8. After the pile has cooled, turn it to mix materials from the center with those from the edges. This means emptying the bin onto a big sheet of cardboard, mixing, and restacking it in the bin to cook for another week. Moisten again, if necessary.
9. Let it cook again and turn again when it cools. Turn for a total of three times (in addition to the initial mixing). Finally, cover the pile and let it cook for another month or two.
10. When most of the material is dark, crumbly and sweet-smelling, it’s ready to use!
To request the comprehensive booklet “Composting Yard and Food Waste at Home,” contact Seattle Tilth’s Garden Hotline at 206-633-0244 or at help@gardenhotline.org.