Organic Lawn Care Project

Organic Garden Fertilizers

To create an apparently healthy, vibrant and green garden, the common practice has been to add synthetic fertilizers. It has not always been this way, and with the growing realities of environmental destruction caused by runoff, those little granules you spread on your lawn are increasingly being seen as a public and environmental hazard. Some jurisdictions have banned cosmetic fertilizers, and this will likely lead to province-wide and even a country-wide ban in the near future.

The Problem with Chemical Fertilizers

Chemical fertilizers, developed over a hundred years ago, were originally used in agriculture to increase crop production. Without them, we would never be able to feed our current global population. However, synthetic fertilizer must be applied properly and in very strict concentrations based on local soil conditions. Most farmers do not have the resources nor the education to test their soil, instead, opting to blanket their fields in a general dose. The problem is compounded by little or no public education on how to properly handle and apply fertilizer, leading ill-informed homeowners to spread large amounts on their lawns. Synthetic chemical concentrations in the soil are now far higher in urban areas than on farms.

All this extra fertilizer washes away from the soil into waterways, making lakes too rich in nutrients. The result is an explosion of growth of algae, which strips oxygen from the water, suffocating fish and other aquatic life. This is a major problem in Lake Winnipeg, which is experiencing unprecedented toxic algae blooms over the entire lake.

While new research and technology is needed to create agricultural fertilizers with slower-release nutrients that don’t wash into waterways, homeowners can fix these problems now by avoiding chemical fertilizers all together.

An Introduction to Organic Fertilizers

So, what can you use as a replacement? Simple – only a few decades ago, there was no such thing as chemicals in urban gardens, and they survived just fine. Therefore, it’s time to re-introduce organic fertilizers.

Unlike chemicals, organic fertilizers are naturally slow-release, meaning they do not release all their nutrients at once. This means little nitrogen run-off and no pollution. Best of all, natural fertilizer adds food not only to your plants, but to the good microbes in your soil that are needed to regenerate and keep your soil healthy in the first place. In fact, being an organic gardener is all about building up the health of the soil. Synthetic fertilizers only add concentrated nutrients for your plants – they add nothing to the soil itself.

Breaking the chemical dependency of your garden will take time. Chemicals provide a short, strong boost to your plants. This may seem like a good thing, but it is only cosmetic – your grass and flowers will not grow strong roots because there are so many nutrients readily available.

When you switch to slow-release natural fertilizer, your plants may have difficulties adjusting in the beginning. They must first kick the chemical habit and begin growing strong roots – they must now work for their food. Weeds will quickly form, which will give one the impression that organic gardening does not work. Be patient, and think long-term. It takes time to rebuild soil health.

To learn more about reducing your pesticide and chemical fertilizer use on lawns, the Manitoba Eco-network has workshops on organic lawn care.

Types of Organic Fertilizers

Every natural fertilizer contains trace elements, which plants need in minute quantities, and major nutrients, which are needed in larger amounts. The formula of the three major nutrients -- nitrogen (N) phosphorous ( P) and potassium (K) is shown on the labels in the percentage by weight in which they are contained.

Different areas of your garden will need different types of fertilizer. Fortunately, there are three types of all-purpose fertilizers you can use in every area of your lawn and garden – compost, mulch and composted manure.

Compost – This is the best material to build up healthy soil. Compost is the natural break-down of organic material into dark, rich soil. It is also called humus, which is what lies on the forest floor. While equivalent to a mere 1-1-1 fertilizer, it acts as a conditioner, retaining water, breaking up clay and adding valuable microorganisms and nematodes, all vital to soil health. The humic acid in the compost will also release natural nutrients already in the soil, so the apparent low-nutrient value is made up for its powerful soil-amending properties.

If your soil has only known synthetic fertilizer, add a layer a few centimeters thick and mix into the soil in the spring and fall. As compost builds up the soil’s organic matter in the long-term, you can add less once your soil is rich and healthy. Remember the organic gardening mantra – concentrate on the health of your soil first.

Mulch – Mulch is a protective layer of material placed atop soils. Use natural mulches to help retain moisture, keep the soil at a more even temperature, and provide shade and a cover to repel weed growth. As the mulch decomposes, it adds nutrients to the soil.

Manures and compost can be used as mulch, but the easiest way to add mulch to your lawn is through grass-cycling. This is simply the practice of leaving the grass clippings on your lawn. Clippings are a high source of nitrogen, and as they are 90% water, they will quickly decompose into the soil.

Do not grass-cycle if your grass is tall, as this will leave unsightly clumps on your lawn that will decompose too slowly. Instead, cut frequently (once a week in the spring) and adjust your mower to a higher setting so as to only cut one third of the grass. This will mean a healthier, stronger plant and smaller clippings. Keeping your lawnmower blades sharp also prevents damage to your grass.

Composted manure – Manures are high in nitrogen, phosphorus and potassium, and the levels are different for horse, cow, sheep, chicken and vegetable-based "green" manures. Until the advent of chemical fertilizer, they were the primary fertilizer on farmlands, and are still in wide-use today. Similar to chemicals, though, fresh manure holds the danger of nitrogen run-off, which is one of the concerns of increased hog production in this province.

Composted manures do not have this run-off problem. The composting process lowers the amount of nitrogen and locks the remainder into stable compounds. The high heat generated by composting also kills any weed seeds and pathogens such as E.coli. The other obvious advantage is that it will look and smell like soil! Therefore, for an urban garden, use only composted manures.

As with compost, add a layer of manure to your lawn and garden. A good practice is to mix compost and manure at the same time. Your soil will be regenerated by the compost and nutrients will be added by the manure.

Other Organic Fertilizers – Apply in Proper Concentrations

Along with compost and manure, plants and lawns need protein as well. Organic “meals” provide the proteins necessary for plant health. Use different meals for different types of plants.

Bone meal – A good source of phosphorous and calcium, which makes up between 2% and 5% of the total composition. Bone meal is often used for tomatoes and bulbs.

Cottonseed meal - A good organic source of nitrogen and trace elements. It has an acidic pH and is often an ingredient in all-purpose natural fertilizers.

Fish meal - A natural fertilizer made in meal form that is high in nitrogen and phosphorous.

Soybean meal - Made from soybeans and is used primarily as a source of nitrogen or as a soil amendment.

Epsom Salts - Used to treat soils and plants deficient in magnesium and sulfur. Because of its high salt content it should not be used on soils that are already high in salt.

Gypsum – Also known as calcium sulfate, it’s a good source of calcium and sulfur. It is an inexpensive material to use for neutralizing acidic soils, and it also helps to break up heavy clay soils so air and water can penetrate.

Contributed by Goorganicgardening.com - click to read more organic gardening information and composting methods.

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