This year many of us went back to our gardens to grow more food in the face of an uncertain future. Since plants constantly remove nutrients from the soil, if these nutrients are not replenished, plant health in your future crops will be jeopardized.

Your garden will never be as good as it was the year before. So here are my four secrets of successful soil building.

Secret Number One:
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, vary the layers of material when building the compost pile as much as possible. For the fastest and most thorough breakdown from heat loving thermophilic bacteria, turn the finished pile once to aerate it and moisten it, if necessary, with a running hose.

Secret Number Two:
Some gardeners love them and some gardeners curse them but leaves are a wonderful resource. Shredded leaves break down very easily and they 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 dry leaves on your driveway. 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 a soil-building mulch.

Leafy Tips
• Large trees such as oaks, maples, sycamores and chestnuts are wonderful sources of nutrient-rich leaves.

• Store leaves in fall for layering into compost throughout the year. TIP: A circular cage of fencing wire, or four posts wrapped with chicken wire, is a simple space[1]saving way to store leaves.
• A heap of leaves will break down into a pile of rich, crumbly leaf mulch in one year (faster if you turn the pile).
• Don’t position leaf piles under trees or hedges where fibrous roots will grow into the pile. TIP: If you must, put landscape fabric down first as a barrier.
• Don’t save leaves showing signs of disease, such as rust, black spot or mildew, since pathogens present may survive. Dig a hole and bury them in the garden, where microbes will get to work destroying them.
• Avoid shiny, waxy leaves, such as arbutus. They are slow to break down due to a waxy cuticle.

Secret Number Three:
If you live near the ocean, head down to the beach after a winter storm, scoop up leafy kelp that has piled up, and add some seaweed to your food garden. Seaweed contains all the micronutrients and trace elements essential for the healthiest plant growth. It can be added directly to the garden as a thinly-layered mulch and it rots down really fast. Many gardeners worry about salt build-up, but the volume that is spread on the garden is proportionately small, and heavy winter rains will dilute salt residues. Another way to get seaweed into your garden is to plant using purchased granular kelp.

Secret Number Four:
Add aged animal manure to the soil for a boost of nitrogen. Local farmers and horse owners are always eager for gardeners to take away their stockpiles of manure. Organic gardeners should be concerned about the use of growth hormones and antibiotics in conventional livestock farming however, as well as genetically modified 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 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. Seed your green manure crop in the fall. Allow it to grow to a certain stage and then dig it into your soil in spring. The decayed matter will provide food for the soil web of life, the worms, microorganisms and other soil-borne organisms, which break down nutrients and make them available to plants. Green manures thereby increase soil fertility and improve plant health.

Green manures that are legumes, such as field peas and favas, have the additional benefit of having bacteria on their roots that fix nitrogen from the air and add it to the soil. By putting down roots that hold soil structure together they also prevent erosion.

Bare soils are vulnerable to being leached out or eroded by heavy winter rains. By storing valuable plant nutrients in their roots, green manures hold plant food in the soil.

The basic tenet of organic gardening is “Feed the soil, and the soil will take care of the plants.” I hope you will take advantage of these freely available four secrets of successful soil building so that you can anticipate great harvests in your garden next year

Carolyn Herriot is author of The Zero Mile Diet and The Zero Mile Diet Cookbook Available at your local bookstore. 
She grows IncrEdibles! in Yellow Point. 
www.harbourpublishing.com/title/ZeroMileDiet

See all articles by Carolyn Herriot