How to Make Organic Garden Soil
The Secrets of Topsoil Building
For years I have been experimenting with feeding my topsoil so I can grow the healthiest plants. Not the plants in my garden are so lush and healthy I feel I have hit the nail on the head, so I want to let you in on my discoveries. They are so simple, and use only materials from natural sources. Best of all, they’re all free!
Before I share my ‘secrets’ with you, I’d like you to consider this little bit of basic logic. If soil provides nutrients essential for plant growth, then topsoil quality will determine the health of the plants. As they grow, plants constantly remove nutrients from the soil. If these nutrients are not replenished, then plant health is jeopardized. Insects and disease are attracted to unhealthy plants, so all the gardener’s problems begin when soil becomes depleted of essential plant nutrients. This is why the basic tenant of organic gardening is “feed the soil, and the soil will take care of the plants.”
Soil organic matter is created by decaying plants and the dying leaves, twigs and flowers that pile up loosely on the soil surface. Millions of soil-dwelling insects and organisms assist in the process of breakdown and decomposition, and their carcasses will eventually also enrich the soil. This continual process of decay is an essential part of nature’s cycle, and it is from this that fertile soil is created.
Contrary to popular belief, chemical fertilizers with synthetic origins do not restore soil health and fertility; in fact, they actually destroy physical and biological properties of soil. They can even combine with minerals already present, making them unavailable to plants. High concentrations of nitrogen, phosphorus and potassium from chemical fertilizers glut and overload plants. Plants outwardly look lush, but fast growth produces weak and watery tissues that attract pests and disease.
Replicating nature, by replacing soil nutrients and protecting the fragile soil web of life, results in healthy plants that do not attract problems with pests and diseases. All it takes is a bit of time in the dormant seasons – November, December, January and February – feeding the soil. These are the months when it’s cold out and you will relish some outdoor activity and exercise.
- Add compost to your garden. Compost is the gardeners’ version of humus, but it is produced much more quickly. The quality of compost as an organic soil additive depends on the residues from which it is made, as well as the extent to which decomposition has occurred. TIP: For best results, very the layers of material when building the compost pile as much as possible, and provide air, moisture and heat for the fastest and most thorough breakdown.
- Add leaves and leaf mulch to the garden. Shredded leaves break down very easily, and create a soil tilth that is wonderful to work with and teems with earthworms. TIP: In the fall, run a lawnmower over a pile of leaves on the drive way. This reduces bulky leaves to one tenth of their volume, and results in a manageable pile of shredded leaves. Spread these over your beds in six-inch layers as soil-building mulch. Tree roots penetrate widely through topsoil and deep into subsoil, taking up valuable nutrients, that are then stored in the leaves. When leaves break down, they return these nutrients to the soil. Take full advantage of stockpiling leaves. I heap mine in a corner of the driveway and just Forget about them. By spring the pile has started to break down into coarse leaf mulch, which we use in potting mixes and as garden mulch. After one full year, the pile will have broken down into beautiful, rich black leaf mulch, the texture of superb garden soil. This is perfect for mulching and enriching the garden.
- Add animal or green manure for a boost of nitrogen to the topsoil. Local farms are always eager for gardeners to take away their stockpiles of manure. I have cultivated a friendship with a neighbor who owns three horses. She only treats them homeopathically and with acupuncture, so I know there are no drug residues in their manure. This manure has no week seeds either, as she uses untreated woodchips in the horse paddocks. Be cautious about manure mixed with hay, as it can spread grass and week seeds over the garden.
Organic gardeners are concerned about the use of growth hormones and antibiotics in conventional livestock farming, as well as genetically modifies grains used in livestock feeds.Try to find a source of animal manure –horse, cow, chicken, sheep, llama, or rabbit – that has not been subjected to these inputs. If manure is not aged (if it’s either still steaming or retains a strong odor), it’s important to age it before you spread it on the garden. Do not harvest food from a garden until 120 days have passed, allowing time for the manure to be broken down and potential pathogens to be neutralized by myriad soil microorganisms
If you prefer, you can add nitrogen to soil using plant matter rather than animal residues. Grow a winter green manure crop of fall rye, winter pea, fava beans, winter barley or winter wheat, and plough it under in early spring. In spring/summer you can grow a warmer climate green manure crop using vetches, clovers, buckwheat, alfalfa, or phacelia.