An organic leap to a compost heap.

If you have a yard, an ideal way to return as much organic matter as possible to the soil is to build your own compost heap. Compost is "ecological," easy to make, and your plants will love you for it. It's like having a backyard trash masher.

Decomposing vegetation provides a home for millions of soil organisms. It opens up the soil, improving drainage and easing the way for root growth, and helps soil hold water and nutrients.

There are a great many old wives' tales about what can and cannot be used, but the rule is very simple; anything that is entirely organic can be composted, except meat or dairy scraps and diseased material. The finer the ingredients are chopped, the more rapidly they'll decompose. Weeds can be put to use in the compost pile. Their nitrogen, phosphorus and potash content are similar to other plant residues and large quantities can provide much humus for the soil. The high temperatures in the ideal compost pile will kill weed seeds, and any weeds that sprout from the top of the heap can be turned under. Some weeds, however, are better off burning such as quack grass, bittersweet and bishop's weed. These weeds have underground stems or rhizomes, making them hard to eradicate.

Wood ashes should be used cautiously so as not to create a nutrient imbalance. Ashes are a strong alkaline and increase soil salinity, although it's good for potassium. Woodchips are superior to sawdust and they do a fine job of aerating the soil and increase moisture-holding capacity, and make a fine mulch for ornamentals.

Any compost container should have plenty of air circulating through it, and never let the compost heap pack down solid. To prevent this, you can mix materials such as grass cuttings and weeds with larger weeds, straw, or shredded newspaper. Be careful with grass cuttings. If you put them on the heap in thick layers, an airless mass of green slime will form, so be sure to layer with other materials.

Certain items are not to be included in the compost heap. Any material that is diseased or infested with pests may infect the heap. Prunings from woody plants take too long to break down.

Ideally, animal manure is the most valuable ingredient in the compost pile because it acts as fuel. Pig, sheep, rabbit and goat manure is well worth using in small quantities and chicken manure is a powerful nitrogen mass. I am lucky to live within a short distance of horse stables where they bag manure and are glad to get rid of it. Manure must not be used fresh, but rather a month or two after the freshness disappears. If manure is unavailable, you can use seaweed meal and dried blood, the best form of organic nitrogen. You can use between six and seven pounds of human hair, which contains as much nitrogen as 100 to 200 pounds of manure and will decompose rapidly in the pile.

Keeping a bale of straw beside the compost heap is well worth the space because straw is an excellent material to mix with cuttings. I soak the straw for an hour or so before adding it to the heap. During the "dog days" of summer, I apply extra water to the heap. Adding lime will neutralize the acidity and keep the compost "sweet" and help neutralize the acidity. Without lime the decaying process takes longer. If the soil is alkaline, it is better to omit the lime and use acidic compost.

During the summer months I have compost ready to use in only two months. In winter, the process slows considerably and the compost will not be usable until spring. To ensure the heap doesn't get too wet, particularly in winter, cover it with black plastic to keep the heat contained.

Although it is not essential to make compost in a container--you can simply pile it up in the corner of your garden--the advantage of a container is that the compost rots right up to the edges of the heap. In an open heap, piled up in a corner of the garden, the edges dry out quickly so the entire heap has to be turned two or three times during the rotting process to push the unrotted material into the center. The size of any compost container will depend on the size of the garden. What works well for me is to use two containers; one that can be left to compost while the other is being filled up.

A compost pile is not a garbage pile

It is best to begin small if this is new to you. Find an accessible but unobtrusive spot. Dig a small pit and add grass clippings, leaves, and small twigs to your pit. Sprinkle with any rotted manure and moisten well Begin to add, day by day, all the vegetable matter that comes from your kitchen: lettuce leaves, egg shells, carrot and potato peels, coffee grounds, tea leaves and citrus peels. Potato peels provide nitrogen to the soil. Peanut shells, rice hulls, molasses residue, and shredded newspapers also decompose quickly. Pet wastes are carriers of organisms that may cause disease in humans, so don't include them in the compost. Keep the pile moist at all times, but not soggy. Continue to cover the vegetable matter with leaves, grass clippings or soil each time you add something to the pile to prevent any odor. Turn the soil over every few weeks and give it the proper air it needs to decay. Keep the soil loose--never pack it down. It usually takes about two months before some of the compost is decomposed enough to use. You can add about one pint of peat moss to each gallon of your potting mix if you wish.

There are several types of compost containers, one being a square wooden box with slatted sides to allow sufficient air to circulate through the heap. It looks good and is cheap and easy to make. Use old floorboards for the sides and you can always find suitable timber at half the price of new wood from a home improvement store or a contractor. For corner supports, I used 4 x 8-inch floor joists. Be careful not to use treated wood as it gives off toxins which will penetrate the soil.

A homemade plastic bin will not rot or rust. Using a saw or utility knife, cut off the top and bottom off a food-grade plastic barrel. Keep one of the cut ends and use it as a lid. Drill one-inch holes around the barrel, about one hole every one square foot for ventilation. This structure allows a small amount of air through the bottom, and the lid keeps the compost dry and the heat in. Another simple homemade structure is a wire and post container. Just place four plastic tomato stakes into the ground to make a three-foot square. Staple or wind about 12 feet of wire netting, three feet deep, to the outside of the stakes. This bin works well as a leaf-mold container and is easily accessible.

To begin the layers of compost, I prefer to start the heap with six inches of horse manure or straw on the ground to make sure there is a free flow of air at the bottom. I add more material, such as large weeds, until I have built a layer six inches deep. Sprinkle nitrogen fertilizer over this bottom layer or add another layer of horse manure. Perform this procedure twice, until you have 12 inches of material, and then cover the heap with a thin dusting of lime. After filling the bin, I cover it with a piece of black plastic or a lid to keep it dry. Attractive mulch can be achieved by using a two to three inch layer of peat moss. This type of mulch mixes well into the compost bin and is ideal because it is an acid medium and, therefore, inhospitable to weeds.

Compost rots down and shrinks quickly so that what seems like a finished heap one week, still has room for more the following week. The way to tell if the compost is really workable is if it is brown and crumbly and offers a sweet smell, like woods in the autumn.

The ideal bin will produce an ideal organic garden, one that retains heat and moisture, is easy to fill and empty, and fends off raccoons, stray dogs, and other animals. Simply adapt your bin to the size of your compost pile and once you begin the pile, it will continue to give your garden years of pure nutrition.