By Rob Symons
Of all the questions I am asked on the subject of home food gardens the majority are about the health of the plants and how to prevent predators. In this column I will focus on health and leave the subject of unwanted visitors to another.
The philosophy behind organic gardening is based on systems theory. Our definition of a system is a set of interacting components in which the behaviour of the whole set is determined by the sum of the interactions between its components.
A garden is an ecosystem of which we, the gardeners are one of the components. Our gardens are of course subsets of a larger ecosystem – the suburb or countryside. There are other ecosystems that are within our garden such as the soil ecosystem. The health of the plants in the garden are dependent on the balanced interactions between all the components of the garden ecosystem.
The most important component in terms of health is the soil ecosystem. This system has co-evolved with plants to store, distribute and dispense nutrients to them. As in humans and animals, good nutrition is the key to health. It makes sense then in seeking to improve the health of our plants that we focus on the soil.
An old mantra of the organic movement is “feed the soil not the plants”. The soil is rich in life and is probably the most complex ecosystem on Earth. However not all soils are created equal. The basic mineral substrate of the soil can vary according to geographic locality in both its mineral content and in its basic consistency. This is where the organic gardener can exercise her role as an ecosystem component to assess and amend the soil to suit the plant types she wishes to grow.
This may be in the form of rock dusts such as dolomitic lime which can increase the calcium content of our ancient, depleted KwaZulu-Natal soils. These rock dusts will do nothing unless they are acted on by the rich microbial life in the soil.
The soil biota need their own nutrients and this is where the cornerstone of organic farming, composting, comes into its own. Composting is the recycling of nutrients back to the soil – a natural process.
A well made compost is rich in nutrients and is mainly composed of a living community of microbes to further enrich the soil ecosystem. The soil will feed the plants and well-fed plants will have effective immune systems that are more likely to ensure optimum plant health.
There are many other factors that will ensure a healthy garden but this column is too short to include them. What I have described is in contrast with our current industrial mode of thinking. This methodology involves feeding the plants directly and treating the soil as merely a medium to hold them. It ignores the soil ecology and in fact poisons it by the application of chemical salts as fertilisers. When plants with weakened immune systems are attacked by pests and disease we further destroy the ecosystem by applying the pesticides and fungicides. This is not the organic way and although it may at first seem productive, in the long run it is destructive.
Organic gardening may take a little longer, but it will achieve sustained health.