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Everything you should be composting this fall

pile of fall leaves

Fall is the perfect time to begin composting. It’s the end of the growing season and there’s plenty of yard debris to clean up, which means plenty of startup ingredients. Plus the cool, dry weather is perfect for working outdoors. More importantly, year-round plants like trees, shrubs, and perennials benefit from a fresh application of compost heading into the dormant season. You can save money, salvage valuable plant nutrients, and divert yard debris from the municipal waste stream by making your own compost.

What makes good fall compost?

If you’ve ever spent time raking or blowing autumn leaves, before bagging them for the trash company to haul away, you’ll be glad to know there is a better way. Fallen leaves, along with most other landscape debris can be composted, including:

  • Grass clippings
  • Annual flowers that have finished blooming
  • Vegetable plants after the harvest
  • Weeds
  • Pruned or fallen sticks, twigs, branches
  • Autumn decorations like pumpkins, straw bales, corn stalks

You can compost virtually any organic waste under ideal conditions, including traditional “taboo” items like citrus fruit, onion peels, and diseased leaves. Just be sure to monitor the green to brown ingredient ratio, moisture content, and aeration.

Start with an easy mix

If you can mow the lawn, you can make compost. When the leaves begin to fall, use a lawn mower with a bagger attachment to collect them. This way, the leaves will be shredded and mixed with grass clippings, which will help both break down more efficiently. Pile the mixture in an out-of-the-way location where it can decompose on its own, or water it, cover it with a tarp, and turn it once a week for faster processing.

compost bin in use

Fill a bin or build a pile

If you have large quantities of material to compost, batch processing works best. Choose from either an enclosed bin or an open pile. Bins keep the moisture consistent throughout the batch, protect the outside surfaces from microbe-killing sunlight, and keep animals out of the compost. Tumbling bins make it much easier to keep the batch aerated. Open piles are fast, easy, and free to build, but take longer to process. Covering an open pile with a tarp can address many of the concerns that bins solve.

Particle size matters

Composting occurs thanks to billions of microbes that colonize the surfaces of the compost ingredients. Smaller particles have a greater surface area, which means more space for more microbes. So, rather than simply piling up pumpkins, tree limbs, and corn stalks, you should chop up bulky items so that the particle size is no larger than 2 inches in any dimension.

Use a lawnmower with a bagger to capture high-nitrogen grass clippings. It’s also great for shredding fallen leaves, annual flowers, vegetable plants, and small twigs. You’ll need to sharpen the blade afterward. A chipper/shredder is another helpful tool for preparing compost ingredients. Use it to grind tree branches up to three inches thick, as well as corn stalks, coarse weeds, and woody vines.

Build a favorable mix of compost ingredients

In composting, all of the ingredients are categorized into the carbon-rich “browns” and the nitrogen-rich “greens.” Browns include things like dried leaves, straw, corn stalks, dried grasses, and shredded paper or cardboard. Greens would be fresh grass clippings, green leaves, green weeds and garden plants, kitchen veggie scraps, and coffee grounds.

The microbes that do the work of composting use carbon as fuel and nitrogen for growth and reproduction. For the best results (fast decomposition, high quality compost) they need a consistent supply of about 70 percent carbon and 30 percent nitrogen.

Items in the brown category and the green category include both carbon and nitrogen but at different levels. To achieve something close to the ideal carbon to nitrogen ratio, start the pile with about 3 parts brown material to 1 part green. You can always adjust the ratio by adding more of one or the other category if necessary.

Maintaining and using fall compost

To get usable compost quickly, a bit of maintenance is necessary. First, shred and pile the ingredients in the 3:1 brown to green ratio, wetting it as you go. The moisture consistency should be similar to a sponge that has been soaked and gently wrung out. Then cover the pile or close the bin and leave it alone for about 14 days.

After the first two weeks, turn and mix the pile. With a tumbler, simply rotate the chamber a few times. Otherwise use a manure fork to manually turn and mix the pile, like tossing a salad. The interior should have warmed to some extent by this point, and may even radiate a significant amount of heat. If it seems dry, add water. If it smells bad, add more brown material. If it’s not getting hot, add more green material. After turning the pile, cover it up again. Repeat weekly.

In six to 10 weeks, your fall compost should be ready to use. You can apply it immediately, spreading a 1-inch layer across the root zones of landscape plants, or store it for later use. Making compost with landscape waste in the fall is an excellent way to close the nutrient loop and reduce pollution. Your yard and garden will thank you for it.

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