Composting Basics
Composting is an easy way to improve your gardens
Compost is the best possible food for your plants, and it is an excellent way to recycle garden waste and leaves, as well as household and kitchen waste. And compost makes it easy to feed your plants. You cannot add too much or at the wrong time, unlike chemical fertilizers or even organic fertilizers. And compost is pretty pH neutral with a broad spectrum of nutrients so you don’t have to wonder about science and soil testing.
What will compost do for my plants and soil?
Improves plant health, growth, and productivity.
Improve soil structure by adding texture, improves drainage and moisture retention, improves air circulation, and improves fertility.
Moderates soil pH to improve nutrient availability.
Feeds your plants slow and steady with a broad spectrum of nutrients. Even good soil is depleted of nutrients as your plants feed.
Microorganisms that love compost help prevent soil borne disease that can harm plants.
Microorganisms that love compost convert soil nutrients into a form that is easily absorbed by plants.
Microorganisms that love compost will help your plants absorb the nutrients efficiently.
Encourages insect and earthworm activity that helps decompose organic material, moves and mixes organic material through the soil, aerates the soil, and leaves rich nutrients behind as waste.
Do I need a fancy compost container?
There are many ways to produce compost, with or without a variety of containers. You just need to think about the space you have available, how much compost you want to be producing, and how much time, effort, and money you want to invest. How much work is involved can be completely up to you, good compost will be produced in every case. There are advantages and disadvantages to each type of composter.
Open Pile Compost
Simply piling up organic waste from your lawn, garden and kitchen in an open space outside is an easy way to get started composting. If you don’t happen to get the right ratios of green and brown material, and you don’t turn the pile often enough, your pile will just take a lot longer to decompose and produce garden ready compost. It is more difficult to heat up an open pile compost, so decomposition slows down and weed seeds are not killed. However, worms and insects, which are very beneficial to composting, love a cool pile. But a pile that reaches 140 degrees in the center will attract very beneficial microbes. A hot pile will need a high carbon to nitrogen ratio (brown : green), frequent turning or stirring to aerate it and adequate moisture. A large pile is harder to monitor, turn, and heat up. Ideal size is about 3 x 3 x 3 feet. Open piles are easily kept moist by rain or irrigation, easy to access for adding material and turning.
Open Bin Compost
A three sided “box” set on the ground helps keep a compost pile contained and somewhat more attractive than a pile. The bin can be constructed of simple lumber, brick or stone, even old pallets. Heat is retained in the compost somewhat better than an open pile and access is pretty good for adding material and turning. Open bin composts are easily kept moist by rain or irrigation. Two or more bins can be set side by side to that you always have compost at different stages. If you only have one bin it is difficult to continuously add new material. To increase air available to the barrel or bin, place a plastic pipe drilled with holes in the center.
Barrel Bin Compost
Upright barrels, bins or boxes are inexpensive, and each type has its own disadvantages but they all present a problem for turning or mixing. A closed barrel similar to a garbage can should not be used unless you cut the bottom out and drill large holes every few inches to provide aeration. The only effective way to turn the compost is to dump it out and shovel it back in. A lid helps you maintain appropriate moisture levels. Upright cylinder bins can be purchased at a reasonable price that have aeration holes, an access hole with a slide up door to remove finished compost, and comes apart in two pieces to give full access to finished compost. A slide lock lid helps maintain appropriate moisture levels. Turning or stirring is just as difficult as with a barrel. You can also make a bin of welded fencing wire. This is very inexpensive and easy, provides very good aeration, contains the pile neatly, and is fully open to receive rain or irrigation, but also drains excess moisture very effectively. Turning or stirring is very difficult. A barrel bin method is generally going to be a slow process because of poor access to the pile, but is a very good option for storing compost materials while you wait for another container to be finished and emptied. To increase air available to the barrel or bin, place a plastic pipe drilled with holes in the center.
Manufactured Compost Bins
Several heavy duty compost bins or boxes are manufactured with a variety of improvements to the basic barrel bins. They are all quite a bit more expensive than basic barrel bins, but specific design enhancements have advantages. An open vertical cylinder with predrilled holes allows for aeration and watering of the pile. Earthmaker manufactures a three chamber continuous system with a shelving system that drops material from one chamber to the next as you add more material. Sounds like a decent system for $150 to $350 depending on where you buy it. Evaluate the designs of manufactured bins, consider pros and cons, and compare prices.
Tumbling Composters
The huge advantage of rotating composters is of course the easy turning. You can give it a spin every couple of days to dramatically speed up the process. BUT, be sure it rotates easily! Every possible rotation method is available. Some are may be difficult to accomplish such as rolling a heavy barrel or sphere, and some crank styles are just plain poorly designed. Most tumbling composters are made to unload easily, but the design is key again. Some are in fact not easy at all. Consider how the design positions the opening, the height of the opening (can you slide your wheelbarrow under it?), how easy is it opened, how large is the opening, and how well is the barrel stabilized while you empty it? A design feature that is important in tumbling composters is a baffle system inside or through the center that aides in mixing. Also an internal aeration system is important. Another design feature that is very important is the rotating system. The barrel gets very heavy and difficult to turn with a crank, and many of the cranking systems are poorly made or poorly designed. Your crank may break with a full load of compost. Some tumblers just have handling holes that are easily grabbed to pull the barrel around using gravity to help. Some of these are actually quite easy to rotate even when full, and the possibility of breaking a crank is eliminated. Check for a means for rain or irrigation to enter, and therefore also allow for excess drainage. If the design does not allow for it, you will have to add water yourself as needed. In general the tumbling composters don’t necessarily make compost faster than other receptacles, except that you are likely to keep the pile well mixed in a tumbler which of course speeds up the process quite a bit.
Getting Started
There is a lot of talk about ideal recipes for composting, but it does not need to be complicated. A heap of garden waste and kitchen scraps will turn into a lovely compost that your plants will love with no recipe at all. But to produce compost more quickly, you need to understand what the pile needs to transform organic waste and debris into compost. Then you can start to pay more attention to recipes as you begin to understand what effect the ingredients have on your compost.
Basic ingredients for Compost
Dry organic material is full of carbon that provides food for microorganisms. Good carbon sources include dry leaves, dried grass, shredded paper and straw. Sawdust can be used but will consume a lot of nitrogen to break down, so use in moderation when you add plenty of green ingredients.
Green material is full of nitrogen that microorganisms need to multiply. Good nitrogen sources include grass clippings, fruit and vegetable scraps, green leaves, weeds, and other kitchen waste such as coffee grounds and tea bags. Fresh manure is a wonderful ingredient if you have access to it, as well as seaweed, and kelp, blood or bone meal.
Water is critical to the composting process. Keep the pile moist but not soggy. If your compost is covered, check to make sure it is staying moist. If it is not covered and gets soggy during wet periods, cover it with plastic.
Oxygen is consumed by the microorganisms as they work so aerating the pile periodically is important. Turning, stirring, or loosening with a pitchfork will create new air pockets between the materials so the microorganisms can keep working.
Following basic recipes will keep your compost pile active and produce finished compost quickly. But when it comes to lawn and garden waste and kitchen scraps, they are not necessarily made available to you all at once in the appropriate amounts. If you keep the recipes in mind as you add to your pile, you can try to make a point to bring the ratios back in line. For example if you have just added a lot of dried shredded leaves, bag your grass clippings to add next time you mow. If you have been producing a lot of fruit and vegetable waste lately, add some shredded newspaper or paper plates. If you have roughly the right amount of brown and green, with the right amount of air and moisture, your compost will heat up. This is a very good sign, the microorganisms are working, growing and multiplying. The heat they produce will also help kill weed seeds that wind up in your pile. The heat will also drive the worms away, but they will return and get back to work as things cool down.
Basic Compost Recipes
Half to three quarters dry browns, one third to one half greens, a shovelful or two of good soil. Create layers 3-4 inches deep and moisten to get things started.
One third fresh green grass clippings, one third dry shredded leaves, one third good soil. Create layers 3-4 inches deep and moisten to get things started.
Half kitchen fruit and vegetable scraps, one quarter fresh chicken or cow manure, one quarter dry shredded leaves. Create layers 3-4 inches deep and moisten to get things started.
Three parts dry leaves, one part green grass clippings, one part kitchen scraps. Create layers 3-4 inches deep and moisten to get things started.
Two parts fresh green grass clippings, two parts straw or rotting hay, one part good soil. Create layers 3-4 inches deep and moisten to get things started.
Two parts dry shredded leaves, one part fresh green grass clippings, 1 part kitchen scraps. Create layers 3-4 inches deep and moisten to get things started.
Three parts dry leaves, two parts green grass clippings. Create layers 3-4 inches deep and moisten to get things started.
Equal parts brown and green of whatever is easily available to you is a perfectly fine start too. Do try to go heavier on the browns vs. greens if you can. Again, create layers 3-4 inches deep and moisten to get things started.
Use a basic recipe that uses what is easily available to you. If you use kitchen scraps or manure, make sure your top layer is dry material to avoid attracting undesirable pests and flies, and prevent odors. After a few to several days, mix up the pile with a pitchfork, or turn it into another pile/bin, or turn the tumbler. Continue to mix up the pile and check for moisture every few to several days. The pile should start to warm up, and eventually get pretty hot in the center. The hotter it gets, the faster the compost will be ready. If it stays 155-160 degrees for four or five days, weed seeds and disease will be killed. Under ideal conditions, compost will be ready in a month. If it doesn’t get enough air, water, mixing , moisture, or heat, it will take longer.
Adding activators or worms is not necessary. Everything will happen on its own. If you prefer to give the pile a boost with activators, just know that the expense outweighs the benefit.
You can continue adding to your pile over time, but each addition will slow things down. Continuing to add though allows you to get a better ratio if started without enough green or brown. The smaller the pieces of the material you add, the faster it will decompose. So shred leaves first and chop kitchen scraps. There are many other organic materials that you can add to your compost with specific benefits to your soil and plants. See the article on Soil Amendments for further information. Also see Preparing the Vegetable Garden for Winter for information about “composting” your fall leaves right in the garden over winter.
Compost Ingredients
Brown dry Compost Ingredients
Dry leaves
Oak leaves in small amounts, they decompose very slowly
Dried brown grass
Small twigs
Shrub prunings, chopped
Dead, dry stalks, vines and plants
Corncobs and cornstalks, shred or chop
Straw
Shredded newspaper
Shredded paper, white paper plates and cups
Paper towels, napkins, Kleenex, paper towel rolls
Green Compost Ingredients
Grass clippings
Fruit and vegetable scraps including rinds and cores, even if rotten
Coffee grounds
Tea bags
Eggshells, crushed
Bread, noodles, crackers. Anything flour based but avoid greasy items.
Green leaves
Garden scraps (spent flowers, bolted lettuce, prunings)
Dead houseplants
Weeds without seeds (avoid thistle and dandelion that can grow from rhizomes)
Fresh or rotted manure (make sure fresh manure gets heated up to kill pathogens)
Blood, bone or alfalfa meal
Seaweed
Hair and feathers
Soil
Rabbit and gerbil waste with paper/wood bedding material
Never add to a Compost Pile
Diseased plants and leaves
Meat, fish, fat
Dairy products
House pet “manure”
Newspaper with colored ink (black ink is generally vegetable base)
Glossy or colored paper
Office paper
Weeds and flower heads or fruits and vegetables with seeds unless you are sure you can get a pile hot enough to kill the seeds
Thorny branches
Waxy evergreen leaves
Ashes, wood chips and sawdust (unless you have the knowledge to know what you are doing)
Plastics
Waxy paper or cardboard
What’s wrong with my compost?
Here is a trouble shooting guide to common composting problems.
Compost smells rotten – too wet or not enough oxygen, turn pile and add dry ingredients such as leaves or shredded newspaper. Or meat scraps in the pile.
Ammonia smell – too much nitrogen from grass clippings, kitchen scraps or fertilizer. Add shredded leaves or shredded paper.
Flies – manure or food scraps left on top of the pile
Rodents in the compost – food scraps not buried well enough or meat or dairy products in the pile.
Dogs digging in the pile – never add fish and meat or bone scraps, or anything greasy.
Maggots in the compost – Meat scraps in the pile.
Fire ants or red biting ants – the pile may be too dry or kitchen scraps not buried well may be attracting them. A hot pile will drive them out.
Insects and slugs in the compost – This is a GOOD thing!
Compost is dry inside – the pile is too small, or too much dry or woody material, or not enough water. Turn the pile and moisten or add fresh green material. If you have large woody pieces, chop or just wait for nature to do its work.
Compost is not heating up – pile is too small, too dry, not enough nitrogen from green material, not enough air, or it is very cold outside.
Damp but not composting – not enough green material, add some grass clippings or kitchen scraps.
Compost pile size is reduced but doesn’t look finished – sift out woody and unfinished material then use the finished compost.
Slimy clods in the compost – too much grass clippings and not well mixed. Add brown material and mix well.
Now you have a wonderful, rich, organic soil conditioner and fertilizer to dig into your gardens. Or you can use it to top dress around plants without disturbing the roots, the worms will take care of “tilling it in”.