Editor’s note: This article has been updated from its original text.
Seize the moment! Autumn is the season to gather materials for composting. The wealth of carbon-rich matter will benefit your compost all year long.
The key to successful composting is maintaining a balance between carbon and nitrogen materials in the compost bin. A healthy compost pile should have about two-thirds carbon (brown) materials and one-third nitrogen (green) materials. The carbon-rich materials provide aeration to speed up the composting process, eliminate foul odors, and help produce a light, fluffy finished compost.
Families often have plenty of nitrogen-rich materials to compost, but carbon-based materials are more difficult to gather all year round.
Families who maintain backyard composters usually have plenty of nitrogen materials to add throughout the year: kitchen scraps, fruit and vegetable peelings, coffee grounds, grass clippings, and other fresh materials. However, the carbon-based materials are more difficult to gather during the winter, spring, and summer months. These include leaves, vines, shrub prunings, straw, dried garden waste, and other items which are plentiful in autumn but less available the rest of the year.
Related: 7 Signs Your Compost is Struggling (and What You Can Do About It)
The following tips will help you make the most of autumn’s offerings. These simple practices will keep you in steady supply of compost all year, and by starting now you’ll have finished compost for early spring gardening. Visit our main composting page to learn more about the basics of composting at home, including a list of compostable materials.
1. Gather leaves and grass clippings.
Leaves are one of the most valued compost materials because they are carbon-rich and small enough to be easily incorporated into the compost. Deciduous leaves are best; do not use evergreen leaves such as holly, laurel and conifers.
Wait until the leaves start turning brown before raking them up. Some leaves can be left under trees and shrubs where they will compost themselves. This helps to reduce the amount of new mulch needed to cover the areas surrounding your trees and shrubbery.
Fresh grass clippings are nitrogen rich and serve as compost activators. Add grass clippings to your compost in thin layers to prevent matting. Then add twice the volume in brown materials to balance the carbon-nitrogen ratio.
2. Too many leaves? Try 'leaf composting'.
If you have too many leaves to incorporate into the compost bin, you can simply compost the pile of leaves by itself. The leaf pile should be at least four feet in diameter and three feet in height. Include a layer of dirt between each foot of leaves.
The pile should be damp enough that when a sample taken from the interior is squeezed by hand, a few drops of moisture will appear. A piece of plastic sheeting over the pile will keep it from getting waterlogged. Weight the sheet down at the edges with rocks, but try not to compress the leaves too much. The pile will compost in four to six months, with the material being dark and crumbly.
Leaf compost is best used as an organic soil amendment and conditioner; it is not normally used as a fertilizer because it is low in nutrients.
3. Collect the skeletons of finished annuals.
Annuals from your vegetable garden which have finished fruiting and are now dying back can be set aside for composting. Large-bodied plants like tomatoes and broccoli can be chopped a bit smaller to make them easier to compost, but it is not advisable to put the root mass into the compost.
Avoid composting any plants which have disease or mold problems. In theory, the heat from the composting process will kill disease spores, but in practice not all compost piles attain maximum heat potential.
Related: 10 Pro Composting Tips from Expert Gardeners
Thick stems and branches should be left out of the compost. They can be tossed into any low areas of your yard as ‘landfill’, as they will eventually break down.
Flowers also contain many nutrients that are ideal for composting. If your annuals have gotten “leggy,” pull them up and toss them in the compost pile and till the bed. Leave the fall perennials while the leaves are green, and then trim them back once they turn brown and compost the leaves.
4. Separate materials for layering in your compost.
Set the materials you’ve gathered into two separate piles alongside your compost bin. One pile is for coarse materials such as stalks, finished annuals from the garden, branches, and shrub prunings. The other pile is for finer material such as leaves, grass clippings, and smaller garden debris.
As you begin to fill your compost bin, remember to keep combining the “green” ingredients like kitchen peelings and the “brown” ingredients like leaves, twigs and shredded paper to ensure you get a good quality compost.
5. Add leaves in small batches to avoid matting.
The composting process speeds up when the materials are well mixed. Add just a few handfuls of leaves at a time to the compost bin; if you add too many leaves they will mat together into a soggy mass and slow down the process.
6. Store extra material for future composting.
We store dry autumn leaves in burlap sacks and keep one sack next to the compost bin. As kitchen scraps and other ‘green’ materials are added during the winter months, a layer of leaves can be tossed on top. This helps balance the green materials and areate the compost for faster results.
7. Save wood ash.
If you have a wood-burning stove or heater, autumn is the time for cleaning out the ash box and chimney. Save the ashes from the stove box (but don’t use the chimney sweepings) add them to the compost bin. Use only ash from clean materials and sprinkle onto compost to avoid clumping.
8. Cover the pile or use an enclosed composter.
The compost pile should be moist but not sodden. Any open compost pile should be covered with a tarp to shed excess rain. Ideally, enclosed composters should be used because they retain the moisture from the materials being composted, deter pests such as raccoons and mice, and speed up the composting process.
How much is enough?
The short answer is: There’s never enough. Our family of four can easily fill a nine cubic feet backyard composter three or more times in a year. It may seem that 20 – 30 cubic feet of compost is a lot, but once applied to the vegetable patch and the shrub beds, there’s little left to top-dress the lawn.
Related: How to Use Finished Compost
Now that we are aware of the problems associated with lawn care chemicals, using compost for lawn fertilizer is an ideal organic substitute, provided there is a ready and ample supply. You can appy compost directly on established lawns once a year, adding about a 1/2″ layer. (You can also apply corn gluten at the same time, effectively making your own organic ‘weed n feed’.)
To prepare soil for a new lawn, apply two inches of compost to six inches of soil. Compost tea, a liquid form of compost which you can make, is especially effective on lawns and can be uniformly applied using a sprayer.
We are adding a second compost bin for this purpose. So even a small home with approximately 3500 sq ft of lawn, shrub beds, vegetable garden (combined) can use two compost bins, each cycling twice a year.
