When you are forming your compost pile you don’t really have to get too technical. Getting an exact 30:1 ratio of C to N is not necessary, and probably not possible for you to measure. Estimating will work fine. In fact, if you make sure you have a variety of materials, with emphasis on the brown and yellow bulky stuff, and you keep them thoroughly mixed in your pile you will be 90% of the way there. Below is a list of materials you can include in your pile, along with the C:N ratio:
|Alder or ash leaves||25|
|Manure with bedding||23|
|Straw, cornstalks and cobs||50-100|
Some Other Commonly Used Materials:
Ash – Wood ash from your fireplace or stove is valuable. It is an excellent source of potash (potassium). Use sparingly, however. A fine sprinkling every 18 inches or so is plenty.
Feathers – If you raise chickens, turkeys or other fowl, these are high in nitrogen and can be composted
Garbage – Organic kitchen refuse is excellent. No grease, oil or animal fat. Meat scraps can attract flies, so bury them deep in the pile or avoid them. There may be city or state ordinances that restrict your use of food in compost bins.
Grass clippings – Grass is an abundant source of material, maybe too abundant. Much of the time you should leave the clippings on the lawn as they will provide nutrients back into the soil. Once in a while, though, go ahead and add them to the pile. If you do, however, you should either dry them out or cover them with other ingredients right away.
Hay or straw – These should be weathered in the field for a while before composting. Hay or straw that has become spoiled, so is unusable for livestock feed, is the best kind for compost bins. You may be able to find a local farmer who is happy to unload “spoiled” hay or straw for little or no money.
Hedge trimmings – These are usually course and tough to break down unless you want to chop them up finely. Some people lay them out on the lawn and run over them a few times with the lawn mower. However, you can occasionally add a layer of unchopped trimmings, too, as this provides good air penetration.
Leaves – Leaves are a gold mine of nutrients for the compost pile. The deep growing roots of trees find minerals in the subsoil that would otherwise be unreachable and pass these nutrients out to the leaves. Leaves decompose slowly on their own, but if you chop them up (such as with the lawn mower) and intermix them with other items in the pile they will decompose much more quickly.
Leather waste – leather dust is very high in nitrogen.
Newspapers – Newspaper make an ok filler, used sparingly. They don’t have much organic material. Shred the paper before adding so it doesn’t mat. Nowadays, most newspaper inks are vegetable-based dyes that are completely safe.
Peat moss – The key benefit of peat moss in the compost pile is that it decomposes much more slowly than most anything else, and also adds texture to the pile.
Pine needles – Another good texturizer, and they also break down slowly. They will make the pile slightly more acidic.
Sawdust – Should only be used in sprinklings as it is very high in carbon. Too much in one place and it will block out air and decompose extremely slowly.
Seaweed (Kelp) – High in potassium and rots very easily. It can be mixed with something that is high in bulk, like straw.
Sod – an excellent material as it includes both loam (topsoil) and organic matter. Don’t put it in a big pile though, but spread it out and mix throughout the pile. Or, lay it on top to act as an insulator, placing it upside down with the roots facing up.
Weeds – Most weeds can be safely added to the pile, even if they’ve gone to seed. When the pile reaches maximum temperatures of 160 degrees the weed seeds will be killed. If you do use a lot of weeds in your pile you should make sure to include plenty of ingredients that will heat the pile that hot.
Items you should not put in your compost pile:
Coal, charcoal – too high in carbon and sulfur
Diseased plants– Although the “thermal kill” of a compost pile that reaches 160 degrees should be enough to kill plant-borne diseases, it is usually not worth the risk to try it. The consequence if the disease is not killed is that all of the compost could become contaminated and passed on to the whole yard.
Pet litter – Pet feces can contain dangerous organisms. Better to flush them down the toilet or dispose of them in the garbage can.
Additionally, you should include at least some activators in your pile. As mentioned earlier, an activator is a material that is high in nitrogen. These have the effect of helping the pile to heat up and compost much more quickly. There are natural and artificial activators.
Some excellent natural activators:
Compost – When you empty out your compost bin to use it in the yard, it is a good idea to save a little to mix in with the new pile. Finished compost already is full of the kinds of microorganisms your new pile needs to get started right. A 2-inch layer added between every 12 inches is an excellent way to go.
Soil – Like compost, soil is teeming with microorganisms needed in the pile. With soil, adding 2 inches for every 6 inches of other materials works best.
Manure – This is one of the most valuable materials you can add to your pile. If you want to set your compost pile on fire you must get some of this. It is rich in nitrogen and microorganisms. It also contains phosphorus and potassium. Some manures are so “hot” they may kill off too many of the microorganisms. Well-rotted manure is best, to prevent this.
In addition to these, you can also include artificial activators. These are chemical fertilizers. Some people frown on using chemicals to build something that is supposed to be as natural as compost. It is up to you whether or not you feel comfortable using such substances. If you do, look for a “complete” fertilizer, such as 10-5-10. Most people who use a fertilizer will use about 1 cup sprinkled over a 10-foot surface area, piled 6 inches high with other organic materials.
After the initial build of the pile it should heat up within just a few days and reach maximum temperature in less than a week. After two weeks the temperature will have cooled down a lot, and in the center of the pile will be a decent amount of compost. However, the rest of the pile will have a ways to go yet. To maximize your pile’s effectiveness you should turn or stir up the pile periodically. Every two weeks may be ideal, but is probably not practical. Stirring the pile simply means using a pitch fork to scoop and drop the materials, effectively stirring the pile. Turning the pile is usually more effective, however. Turning the pile means to move the pile by scooping the top of the pile off and beginning a new pile with it, continuing until the first pile has been relocated and turned upside down into the new pile.