Homemade compost adds nitrogen and other nutrients to soils. It improves tilth and contributes to microbial action that greatly enhances plant health.

No wonder throwing good stuff from the kitchen down the drain or sending organic materials to the dump is anathema to me and to all other organic gardeners. Almost all of it can be used as mulch or turned into wonder-working compost right here in my own home garden. There are a few exceptions to what can be added to a compost pile. Meat, bones, and gravy are no-no’s in suburban settings because they attract wild and domestic animals, but on farms even these wastes are recycled, usually into the tummies of pigs. Pet wastes must never be added to compost, since they contain pathogens that can harm humans, but chicken, sheep, goat, rabbit, cow, or horse manures are fine.

I have always wanted to practice the art of composting here in Southern California, as I did with my family in the faraway places where I grew up. Imagine my distress, therefore, when many years ago I discovered that, for a number of reasons, composting here is not at all easy.

Making compost is a process of piling up organic matter and letting it rot. Originally, compost piles were simply dumps. Farmers and householders threw everything onto an out-of-the way heap, and after a few years, a gardener or farmer could roll up a wheelbarrow and fill it with well-rotted organic matter that he or she dug from the bottom of the pile. This magical material was dark brown or almost black, smelled pleasantly earthy, and had a fine texture. Often it was full of earthworms. By looking at it, one could not discern what had gone into it. The wonder was that all this took no work at all.

In Yorkshire, England, during the 1930s when I was not yet ten years old, I took great pleasure in watching Viney, our head gardener, digging dark brown or black, sweet-smelling, organic matter from the bottom of his compost heap, and then putting it through a sieve in the potting shed and filling pots for planting. He would tuck all manner of flowers and vegetables into the pots and carry flats of them into the greenhouses that were lined up side-by-side on the edge of the large vegetable garden. I stood beside Viney, watching, my nose reaching the level of his potting bench. The experience was sheer bliss. But this kind of life no longer exists, and is like looking back on a dream — another world from what I experience here and now.

Viney’s composting method was the old, original slow method. Sometimes, the pile got hot; other times, it cooled down again. Once in a while it got so hot — most often from grass clippings — that it would burst into flames. A compost pile here that bursts into flames from spontaneous combustion is a badly maintained pile and could be extremely dangerous; it might start a wildfire. But a compost pile that occasionally flamed and then morphed into a slowly smoldering heap didn’t matter much in a climate where the next rain would wet down the pile and leave it smoking. Besides, Viney’s compost pile was sited in an appropriate location, a safe distance from buildings and hidden behind a tall garden wall. The charred remains of twigs and branches simply added some useful potassium to the whole magical concoction. The action of burning had another benefit as it often broke down organic woody stuff too large to rot as rapidly as the rest.

Though the old-fashioned or slow-compost pile was a haphazard thing that took care of itself, the mysterious biological events that took place inside it were the essence of science. The heat that builds up within a compost pile and causes the materials in it to rot is the result of microbial action. By piling up organic materials and keeping them damp, one allows microscopic organisms to eat the organic matter, breaking it down and creating heat and nitrogen in the process. When this material is rotted enough so one doesn’t know what went into it, then it’s time to dig it into the ground, where it becomes what we call humus.

Today’s manufacturers often label bags of compost as “humus,” but this is a misuse of the word. Technically, soil is the thin layer of ground rock and organic matter that covers the surface of our planet Earth, and humus is the partially rotted organic matter that exists in soil. Compost does not become humus until it is added into the soil. Then, as humus, it rots further in the ground and in the process gives off nitrogen into the soil in a form that plant roots can absorb and use for growth. Humus also contains natural fungi that contribute to plant health. Beneficial fungi in homemade compost attack and kill harmful fungi that cause plant diseases. So, making homemade compost does much more than simply adding to the organic content of soil; it is also a fine way to control plant diseases without the use of poisonous sprays that cause cancer, killing us along with whatever else they are meant to attack.

In the 1930s and ’40s, Sir Arthur Howard, J.I. Rodale, and other writers promoted a more complicated and scientific method of composting. Over a period of 30 years in India, Howard had seen large-scale hot composting done in that country. Based on what he saw, he developed a method of hot composting that could be managed by gardeners working on a smaller scale. Howard’s new method produced compost more rapidly than the old method used by Viney and his ilk. Hot composting consists of alternating more or less even layers of nitrogenous materials (wet or green organic materials, such as manure, green leaves, or grass clippings) with carbonaceous materials (dry organic materials, such as wood shavings, dry leaves, chipper materials, raw sawdust, or bagged rabbit litter). First, you create a pile about three feet square — this is the optimum size — by alternating these layers of nitrogenous and carbonaceous materials in roughly even quantities, then you keep the pile damp, and finally you toss and turn it to mix in air. Mixing in air keeps the heat going by providing necessary oxygen, but it also cools down the pile, thus preventing it from getting too hot and bursting into flame as Viney’s pile used to do.

Unlike the slow method, fast composting is scientific, and if you don’t do the process just right a few things can go wrong. If the pile is wet and smelly, that’s a sign you put in too much nitrogenous and not enough carbonaceous material. Adding a handful or two of sawdust or some chopped dry leaves usually fixes this. If, on the other hand, your pile doesn’t heat up even though you put it together correctly, that is a sign it’s too dry and you need to add a little water, or perhaps you put in too much dry carbonaceous matter and not enough nitrogenous waste. In that case, you need to add some nitrogenous materials like grass clippings, hot manure, or even human urine, or a few fish heads or fish entrails. (Fish parts will heat up a pile quickly, and it’s safe to add them in an enclosed drum composter since animals won’t be attracted.) If you’re a man and your compost pile is located in a private part of the garden, simply stand there and pee on the pile, and it will heat up the pile fast. You may laugh at me for this suggestion, but I might as well be truthful: people have been using this simple, built-in method of adding nitrogen to soil and soil amendments for thousands of years. Human urine is a clean and strong source of nitrogen. You need to dilute it in order not to damage plant roots. It is a bit too salty to use for feeding roses and vegetables in dry Southwest climates as is done in many other countries, especially Finland, but it’s fine for heating up a compost pile. It also includes phosphorus and potassium.

The best thing about hot composting is how quickly it works when done right. You can actually get a marvelous product ready to use in six weeks. It sounds impossible, but if the mix is right and you keep tossing the pile, hot composting works like a dream. While tossing and turning the pile, one should put the cooler bits into the middle and the hotter parts on the outside. This is fun and satisfying work, and it’s a great way to lose weight, but one needs to have strong knees. After I got knee replacements, I had to give it up. Composting didn’t ruin my knees, however — being thrown from wild horses accomplished that.

Since the 1950s, I’ve lived and gardened in Del Mar, and during that time have enjoyed a long history of trying out various composting methods. Recently, I decided I should write down this composting history and share it with others so they can reap the rewards of composting while avoiding the pitfalls. Having spent my early teen years on my family’s organic farm in Bucks County, Pennsylvania, when I arrived in Southern California in 1944, I was steeped in the idea that we need to return all organic waste to the ground. I also expected that everyone would feel as I did on this subject and was shocked to discover that this was far from the truth. After I married, my husband and I settled in Del Mar next door to his parents, and I searched for a place to build a compost pile on my property. I made the mistake of discussing this subject with my in-laws, the late John Lloyd Wrights, a talented, fascinating, but strong-willed pair. John was the second son of Frank Lloyd Wright; my husband was the son of John’s wife, Frances. The Wrights grew up in Chicago and environs, but even John, who used to play on his grandfather’s Wisconsin farm in summer, could not accept nor believe in the correctness of composting here in California. They did not want me to have a compost pile, since they were convinced it would bring rats and other animals. Their point of view had some merit.

Soon I learned another way to compost that required no rat-attracting heap. I learned that the San Diego Zoo’s composting method was to chop up all garden trimmings and use them as mulch on the ground under the very plants from which they had come. The Zoo’s method was combined with mature plants and heavy overhead irrigation, so nothing was unsightly and things rotted quickly. Imported water was plentiful in the 1950s, and though we were aware we lived in a dry climate, even the Metropolitan Water District encouraged plentiful use of irrigation in order to keep water rates low.

I adopted the Zoo’s method of composting in my brand new and sparsely planted garden. I was trying to improve the sandy soil that had almost no organic matter in it. But this too met with a hue and cry and considerable amusement once the Wrights discovered what I was doing. They didn’t understand mulch but thought every leaf should be swept up, bagged, and sent to the dump. Like many people who move to California, they had no idea that even eucalyptus leaves will gradually rot and add their goodness to the ground; all it takes is time. Even the oils in eucalyptus leaves eventually break down in the compost process and do no harm. Pine needles can also be composted, but it is wise to compost them separately because of their acid content, and then use the compost for acid-loving plants such as camellias. Uncomposted pine needles are useful as mulch for azaleas and camellias, but even today are often swept up by gardeners and sent to the dump.

After my early composting attempts had failed due to heated opposition, I tried to improve my garden soil by burying kitchen waste straight in the ground, which on my property was little better than pure beach sand. In the early days of my garden, this practice attracted wild animals, including raccoons and the dreaded rats. My garden was still a wild place, without flowerbeds or vegetables. In a more conventional garden, burying wet materials from the kitchen, such as salad greens, cantaloupe and papaya peels, and vegetable peelings is a perfectly good and useful way to add nitrogenous materials to the ground, but unless one buries kitchen waste deeply in one’s vegetable garden or flower beds, or under garden paths, animals both wild and domestic can be attracted to it and will dig it up. Another way is to blend vegetable and fruit wastes with water and pour it straight into garden soil, but this method takes time and electricity. It never seemed sensible to me.

Today, it would be impossible for me to compost all green waste from my garden, though I tried at one time to do this. One day when my children were young, I was reading the Beatrix Potter stories of Peter Rabbit and Benjamin Bunny aloud and thought again of Viney in Yorkshire and our compost piles on the farm, and how Mr. McGregor in Peter Rabbit simply piled everything up and it rotted after a couple of winters. I decided to try once more. This time I hit upon the French Trench Composting method. I was a few years older and wiser and didn’t discuss my current experiments with my in-laws. The site I chose for my compost pit was against a high north-facing natural earthen bank or cliff. It was heavily shaded and near a hose, and though it was right next to the Wright’s property, it was on a lower level. They would never know what I was doing. I dug a trench and threw everything into it. Once in a while, I soaked the pile with water. If stuff was smelly, I threw a bit of earth on top. That’s the French way, and not the way composting is done in England, where it is claimed adding soil spoils the stew. Well, I found out it didn’t. With infrequent watering, my French trench stayed damp and worked like a dream for several years. I added stuff on top, never tossed or turned the pile, and dug lovely, sweet-smelling, well-rotted compost out of the bottom. This was almost as good as our compost piles in Pennsylvania and England had been. ■
— Pat Welsh

Don't miss:Adventures of the Compost Pile, Part 2