Composting is simple in theory, and the basic instructions are available all over the place. But some gardeners are still left with questions. This "FAQ" might resolve any remaining worries about how to build the fall compost pile.
Which compost bin is the best?
The best commercially manufactured bin: A stacking compost bin seems to get the best user reviews of the prefabricated compost units on the market. An earlier popular model, Biostack, has become unavailable but the lookalike "Scotts Organic Choice Compost Bin," is praised for 13 cubic foot capacity, large lid, and ease of use. Users of the stacking bin find it handy, as it can be used whole or in sections and moved easily, with turning incorporated into the moving.
What about tumbling bins? Tumblers can be helpful, but not as foolproof as the ads suggest. Being elevated means tumblers are hampered by cold air on all sides in cold winter climates. Tumblers are very secure against animal pests.
How about stationary bins with doors at the bottom? Forget that door; compost at the bottom of the bin is solid like dirt, and bears the weight of a couple of feet of compost on top. It's all but impossible to scoop finished compost from one of those doors. Move the whole unit, put unfinished waste back in, and shovel up any finished compost.
The best homemade bin: The best homemade bins for serious composting have solid sides such as wood, block or even hay bales. Solid sides help keep the pile moist and warm, especially important when working with mostly dry leaves. Make bins at least 3 feet square on the sides, or 3 feet across a circular bin. Four foot dimensions here are workable, too. Plan a cover or lid to help keep water in or out as desired. Homemade bins vary widely as to material and design. Look at this link from University of Wisconsin Extension for a variety of designs for home built compost bins.
Where should I put my bin?
A sunny location in winter helps the compost stay warm or thaw out after a freeze. (Don't let it dry out.) Place the compost so that unloading will be convenient to the garden. When you start forking out finished compost, you'll have it closer to where you use it.
Do I have to have a bin?
Yes, a bin or enclosure of some kind keeps the materials contained and takes up less room than a casual pile. A contained heap should heat up, and hold the heat, more effectively than a spread out, more exposed mound. Some bins keep animals out, if excluding animals or deterring vermin is a concern.
Do I really have to have a bin?
No. Compost happens, but more slowly, in a pile on the ground. Follow the same guidelines for layering and wetting the ingredients. Allow about five feet square in ground surface area to make a minimum three foot high pile. A compost pile is not necessarily highly attractive to vermin.
How do I turn (aerate, add air to) the pile?
In an open bin, you can pick up some material with a garden fork and flip it over. With a stacking or lightweight movable bin, you can turn by moving the bin. Lift a section or the whole bin and set it just to one side of the pile of compost material. Then use a garden fork to pick up the material from the top down, turning it over into the newly placed bin. Continue until all material is moved. An optional compost aerator tool is a stick with wings gizmo that you use to poke holes in the pile.
When do I turn the pile?
A new pile should warm up within days. Daily turning for two weeks after that should keep the pile cooking. Perhaps more important than adding oxygen, turning compost gives you a view of how the breakdown is proceeding. During leaf gathering season, water and nitrogen are most likely needed.
Can I compost without turning it?
Yes, you can compost without turning. Things may proceed more slowly and unevenly. Build the pile following the usual guidelines, but keep it "fluffier." Perforated PVC pipes layered in as you build can add passive ventilation. Add material whenever you have it, and let nature take its course for several months. Eventually you can fork off some uncomposted material from the top of the pile, and shovel up nice compost from the bottom.
So many leaves; can I really compost them all?
Shred them. Shredded leaves take up less space right away, and break down faster. Use a shredder, or your mower and bagger, or your shredder vaccuum.
Mow some leaves right on the lawn with a mulching blade. Your fall lawn fertilizing and rainfall help them decompose in place.
Bag excess leaves. Add them later when the compost has started to rot and condense down. Better yet, add water and fertilizer to the bag, tie shut, and poke some holes. The leaves will start to break down in the bag.
Create a temporary holding bin for leaves from a large circle of garden fence. Twelve feet of fence will give you a roughly foor foot diameter bin.
I don't have enough "greens" in the fall. How can I boost the nitrogen and get things going?
Cheapest source of nitrogen (the active ingredient in greens, besides moisture) is commercial granular lawn fertilizer. The cheapest inorganic you can find works great. Check the label; use one with a high first number, and NO "weed and" part (NO herbicide.) Try about a half cup of fertilizer per "large bag full" amount of leaves going into the bin.
Effective organic sources of nitrogen: blood meal, corn gluten meal, or alfalfa pellets. Start with three cups of blood meal for each bag full of leaves. Use up to 20 pounds of alfalfa for a cubic yard of leaves (3 feet on each side) to get them hot.
Exact amounts of nitrogen additives are near impossible to give. The chemical balance depends on the weight and composition of the different components. Excess nitrogen will simply "evaporate", too little nitrogen just slows down the process until more nitrogen arrives.
Mow and gather leaves right from the lawn while it is still growing, this gives you chopped leaves with a dose of green. You may need still more nitrogen.
Kitchen waste is a weak green. Maximize kitchen waste; include all but the most difficult to handle food items, and look for more from friends, neighbors, and commercial establishments.
Manure is a green. Fresh manure is greener than aged. Rabbit and chicken manure are stronger nitrogen sources than horse manure.
Easy source of nitrogen for the open minded gardener: urine.
"Additives, activators, starters", do I need them?
No. Compost ingredients have ample biology to start the population. If you like, a dose of compost from a friend's pile will help you get going in the right direction. Sprinkles of garden soil between the compost layers also "start" the bin. Soil supplies microorganisms and can help hold the water that tends to run though dry leaves. If your compost is inactive you need to adjust the moisture, air, or nitrogen/carbon ratio.
Should I buy some worms?
No. Earthworms will come when you have what they like. Don't look for them in a brand new leafy pile. Worms eat bacteria, fungi, and algae growing on the composted material. They can't come right in and eat those leaves the way a caterpillar could. Let your compost cook along for a few months before expecting worms to populate. When your bin has enough moist half rotten goodness, worms will come, make themselves at home, and stay awhile.
What if it doesn't get hot?
Heat is not a requirement. Heat signals the intense biological activity that is the essence of speedy composting. Heat also kills many weed seeds and some diseases. If you're not in a big hurry, and take care not to put weedy or diseased plant material or soil in the pile, don't be overly concerned about "heat."
Are my leaves too dry?
If you suspect the pile is inactive due to dryness, it probably is, especially at this time of year..
Be sure to moisten leaves as you pile them.
Check the pile weekly after the initial fill
Keep the top open to rainfall.
Rake leaves on rainy days.
If the pile has heated, be ready to add more water; the busy bacteria can cook it out.
What's that smell?
Good compost smells remind you of fresh spring soil or a walk in the woods.Your compost is happy, keep up the good work.
Bad compost smells remind you of rotten grass, ammonia, swamp mud, skunk, or vinegar. Your compost is too wet or has too much "green" nitrogen. Add more dry leaves or another "brown", open or spread the pile to help it dry out, turn and stir frequently.
What are those creatures?
Fruit flies and gnats love fresh fruit and vegetable scraps. Larger flies and maggots are less common but like certain items. They all help the decompostion. Minimize them by burying fresh waste or covering it with garden soil.
A cast of crawly things (Centipedes, millipedes, sowbugs, roly poly bugs, earwigs, slugs are some) inhabit the compost area and have roles in the compost ecosystem. Try to ignore them; they are generally not a problem.
Four legged things also help in breakdown, by eating and processing fresh waste. Of course you don't want to encourage rats, voles, or other pesty beasts. Turning and working the compost discourages them and helps fresh waste break down quickly. Exclude animals with solid walled bins, and lids or hardware cloth over openings.
Less frequently asked questions...
that I haven't addressed above may be posed in a reply to this article. I'll do my best to answer.
I grew up playing in the Maryland woods, and would still do it often if life allowed! Graduate of University of Maryland, my degree is in Agriculture. Gardens and natural areas give me endless opportunity for learning and wonder. Naturally (pun intended) my garden style leans towards the casual, and my cultural methods towards organic. I like to try new plants, and have "some of everything" in my indoor and outdoor gardens. Thanks go to my parents for passing along their love of gardening and nature, and my husband and kids for being patient when I get lost in the garden.