When you compost organic waste from your yard and kitchen, you get a valuable soil amendment that benefits your garden and the planet. Digging compost into garden beds replenishes and feeds soil microbes, and helps your soil store and conserve carbon.
The problem is making enough compost to meet your garden’s needs, without bringing in materials that may harbor pesticide residues and other unwanted substances. This is a great season to become an ambitious composter, with leaves, dead plants and other compostable materials in good supply. In most climates, mild temperatures linger long enough to start the decomposition process.
Why not think big? If you have a stationary composter, make plans to fill it to the rim before cold weather arrives. Size matters with open compost piles, too, because large heaps generate and retain warmth better than small ones.
Gathering Your Greens
If you fast-forward a few weeks, short days and falling temperatures will cause many plants that are now green to wither and die. Why not harvest them a little ahead of time as greens for your compost? Lop off and compost old horseradish leaves, take green tips from raspberries, and pull any lush weeds lurking among your fall veggies. If you are growing a quick cover crop of buckwheat, mustard, or oats, the planting won’t miss a few handfuls of plants used to juice up your compost pile.
In my garden, autumn is when the perennial herb known as comfrey becomes a star. Many British gardeners grow comfrey to ferment into fertilizer, but I grow it for its summer blossoms, which attract legions of small bumblebees, and for use as a compost crop in early autumn. The vigorous plants don’t mind losing their foliage a few weeks early. Handfuls of leaves are easy to cut with a garden knife and they make excellent composting greens.
Leaves and Paper
Many insects overwinter in leaf litter, so zealous raking can deprive them of essential habitat, which is of increasing concern in the age of insect decline. But still, there are areas in any landscape where leaves are a liability and must be gathered – decks and patios, driveways, and parking areas. The best use for small caches of leaves is to layer them into a giant compost pile, where they supply carbon balance for richer, green materials.
Recently I received an email from a compost educator in the high desert of Wyoming, where there are few trees to produce compostable leaves. To properly compost gloppy food waste, she was using paper as a carbon source, which works really well. I now save shipping paper, tear it into strips and dampen it before adding it to my stationary composter, home of rotting watermelon rinds, apple cores, and other wet kitchen waste. It disappears in a matter of weeks. Torn bits of damp cardboard work well, too, but take longer to break down.
Speaking of kitchen waste, your compost will benefit if you clean out your refrigerator and pantry shelves. You can wince over this tip, but I wouldn’t ask you to do something I wouldn’t do myself. A quick purge of my fridge yielded forgotten corn tortillas, half-empty jars of pickles, and several shriveled limes, lemons, apples and beets. These treasures were joined by aged lentils and stale granola from the pantry. It’s a win-win when you get a low-chaos fridge and feed your compost at the same time.
Enriching compost with dead flower blossoms may seem like a small thing, but seeds are dense packages of protein and carbohydrates, destined to be transformed into nitrogen. With annuals like marigolds or zinnias, deadheading can push out a few late blossoms, too.
Vegan Food for Compost
I have a steady supply of good manure from my small flock of laying hens, but securing safe manure for composting can be a challenge. You can buy chicken or rabbit manure in bags, or even use the chicken pellets sold as fertilizer as a nitrogen source for composting.
But what if you don’t want to use animal products in your garden? There is a vegan alternative to manure: organic layer pellets. Chicken feed for laying hens is 17 percent protein (mostly from corn and soybeans), which quickly breaks down into nitrogen as it rots. Earlier this year, when rain ruined an open bag of organic chicken feed, I used it as a nitrogen source in my compost, where it was odorless, effective, and more predictable than manure. In compost as in life, this just goes to show how important it can be to think outside the heap.