Organic Gardening Overview

What is Organic Gardening?

"Gardening without the use of artificial fertilisers and toxic chemicals" is probably the simplest definition but also the least satisfying. It is rather negative and implies that you can just sit back and leave it all to nature. This incorrect belief in turn leads to the misconception that organic gardens are wild, unkempt places where every cabbage is riddled with holes and every rosebush is blighted with mildew. Organic gardeners do not just leave their gardens to nature; they use all the methods, techniques and products at their disposal to work, as far as possible, with nature.


Safely dispose of all your chemicals, fertilisers and pesticides so that you are not tempted to use them. This is important as the harm they do will hamper your efforts to build up an organic system.


Think of the soil in your garden as a living environment in which earthworms, beneficial bacteria, and fungi convert organic material and inorganic soil minerals into plant food. Fertile, humus rich soil is a storehouse of plant nutrients which are made available to plants as required and in balanced form. Soil structure is important. Soil must be friable to permit air and water to enter and to allow plant roots to forage through it. This is achieved by the addition of organic material in the form of compost, mulches and green manures.

Composting is possibly one of the most important activities of the organic gardener. It is an extension of nature's own system of recycling vegetable matter and returning it to the soil.

It is a perpetual cycle that has been going on in nature since time began and there is no better way of keeping the soil in your garden fertile and healthy. There are other materials that can benefit the soil which organic gardeners make use of. These include animal manures, blood and bone mixture, seaweed extract, fish emulsion, dolomite, and rock minerals, to name a few!


Strong vigorous plants will resist disease and insect attach, but the most effective agents operating to control insect pests are, and always will be, those that occur in nature. These are the parasites, predators and diseases of the pests themselves. Natural predators of insect pests are often reduced to insignificant numbers by the use of insecticides which are usually non-selective and therefore eliminate both the pests and predators alike. Moreover, many insect pests have developed immunity to one or more of the insecticides which render these chemicals ineffective in controlling them. The organic gardener does all they can to encourage these predators which include birds, frogs, lizards, and may beneficial insects such as ladybirds, lacewings, preying mantis, and several species of wasps. The red wasps you see hovering over your lawn and darting in and out of shrubs and vines during summer months are natural predators of lawn grubs and caterpillars and will keep these pests well under control. Magpies which are often to be seen patrolling suburban lawns and gardens are also busy foraging for grubs in lawns and larvae in soil. Bacillis Thuringiensis, sold as 'Dipel' is a bacterial diseases of caterpillars and is useful in controlling this pest. It is quite harmless except to caterpillars (however, Dipel affects almost all caterpillars even the ones that do not impact edible or productive plants). Crop rotation, companion planting and the use of disease resistant varieties of plants are some of the many methods used by organic gardeners as a means of pest control.


Changing from chemical to organic gardening and farming means discovering how nature does things and adopting her methods. For after all, she as been gardening a lot longer than mankind!

It is a healing process for both the garden and the gardener. Aggressive attitudes that seek to subdue nature and bend her will are replaced by peaceful cooperation and coexistence, and with nature as your friend, you can't lose!


Understanding Soil: Why Incorporate Organic Matter?

Incorporating organic matter into the soil can have several outcomes, affecting the physical, chemical and biological balances in the soil. It can:

  1. change the amount of nitrogen that is available to plants;
  2. change the amount of other nutrients available;
  3. change the way the soil sticks together (soil aggregation); and
  4. change the number and type of organisms present in the soil.

All of these changes are related to the way organic matter is decomposed when it is incorporated into the soil and to the particular type of organic matter used.


The Process

When Organic matter is incorporated into soil, the larger organisms like mites and soil animals break it into smaller pieces. The fungi and bacteria start to decompose it by secreting enzymes. When the enzymes break the molecules into smaller sections, the bacteria and fungi can use some of the energy or nutrients released for their own growth.

If there are nutrients that the microbes do not use, they will be available for other soil organisms or plants to take up and use. When microbes die, their cells are degraded and nutrients contained within them become available to plants and other soil organisms.

Microbes can access nitrogen in the soil more easily than plants can, so the plants sometimes miss out and the plants can become nitrogen deficient. This is why incorporating organic matter into soils can change the amount of nitrogen (and other nutrients) that is available to plants. This will be a short-term effect that happens when soils do not have high levels of organic matter and soil microbes.


The Benefits

If the number of fungi and bacteria associated with the breakdown of organic matter increases, there may be some improvements to the soil structure. Adding organic matter can also increase the activity of earthworms, which in turn can also improve soil aggregation. If organic matter is retained in the soil, the number of microbes in the soil increases. This is because the microbes can use the organic matter as a source of energy and so they can grow and multiply.