Gardening

I must admit that it has taken me a long while to be convinced of the benefits of soil testing. When I started out, most of the established gardens were resisting the obsessive wave of soil analysis which swept across the agricultural and commercial horticultural landscape. There were scientists and graduates from the universities wanting to help farmers and growers by analysing the chemical and physical properties of their soils. Several times each year, technical representatives from the emerging chemical and agricultural corporations would visit major farms, sporting grounds, and established gardens throughout the country. Around this time, I lived and worked on a private estate and was on one occasion harassed by a foreign gentleman seeking...

The best medium for growing healthy plants is a rich, loose, and fertile soil. Earthworms make a significant contribution by loosening the soil and providing plant nutrients in their droppings. When they burrow, worms aerate the soil to provide essential oxygen for bacteria, fungi, and other micro-organisms required for soil fertility. An earthworm can digest approximately half its own bodyweight of soil each day. Given that average populations number hundreds of worms per square metre, the combined effect will be the processing and movement of large volumes of earth each year. Earthworms concentrate essential nutrients and minerals from soil as it passes through their digestive tract. Their expelled waste, also known as cast, contains many...

Over the years, I’ve experienced only minor problems associated with inadequate soil drainage. This surprises several of my gardening colleagues since I have frequently worked in regions where rainfall exceeds evaporation and contributes to an elevated groundwater. In retrospect, I was fortunate to work on private estates where adequate garden drainage was designed and installed, sometimes dating back to Elizabethan times. Of course, natural determinants of poor soil drainage can be sufficiently inherent to defy normal engineering attempts to resolve them. Soil drainage properties can usually be explained in terms of the geographical location, surrounding physical topography, and the compositional structure defined within the various soil...

It saddens me to admit that the prevalence of seriously problematic soils appears to have increased dramatically over the previous few decades. Despite the proximity of international tensions, the world seemed a considerably safer and altogether more stable environment when I started gardening in my teens and early twenties. Perhaps this misrepresents the reality. It might be more accurate to suggest that certain issues were once described in concrete terms, without the numerous complexities and differences of opinion which are routinely encountered in the popular media of today. Like everyone else, I’m confused and disturbed by the reports on global warming, climate change, and species decline. When I look at my original notes for this...

The decision to use a particular type of fertiliser needs to be supported by some understanding of the preferred soil conditions and other requirements of the plants being raised. To grow properly, plants require a broad selection of nutrients. Ideally, these occur naturally and are directly available from soil or compost. The three macro or major nutrients: Nitrogen (N), Phosphorus (P), and Potassium (K), are required in significant quantities. They work together and in combination with other nutrients but each of them has a dominant role in certain aspects of growth and plant development. Nitrogen, for example, is required for shoot and leaf growth. Phosphorus is the most crucial nutrient for developing functional root systems, while the main...

The other night, I became frustrated with my football coverage so switched between documentary channels on the cable network. I managed to catch the second half of a program about earthworms. Prior to final credits, the narrator emphasized the significance of the earthworm’s contribution towards maintaining soil fertility. He then suggested that soil fertility was crucial for the long term sustainability of life on earth. Unfortunately, he repeated the words monotonically and they became divorced from any reasonable sense of urgency. As a keen student of organic principles, I’ve been concerned about the long term consequences of poor quality soils for several decades. Irrespective of the demand for organically grown produce, there...

Making compost from organic waste is an effective and environmentally sustainable means of improving your garden’s soil structure and fertility. Composting is a practical skill. However, achieving proficiency can prove challenging for novice gardeners. One helpful approach is to initially acquire some understanding of the role played by bacterial micro-organisms. A healthy population of these and other organisms will sustain the decomposition process by generating heat and chemical enzymes as by products of their metabolism. Under appropriate conditions the micro-organisms will reproduce in sufficient numbers to transform organic waste into a dark, finely crumbled, and sweet smelling substance. The compost bacteria require a blend of proteins...

The concept of replacing soil nutrients with a range of organic soil amendments is a sound one. When I started gardening more than half a century ago, there was plenty of excitement surrounding the use of synthetic fertilisers and the various chemical treatments which promised to increase the fertility and manageability of the basic soil types. With the exception of a few traditionalists, there was minimal interest in evaluating the effects of natural organic materials on soil productivity and sustainability. I was privileged to work with a group of dedicated gardeners who appreciated the importance of healthy, living soils. When I reflect back, they were quite often ridiculed for their resistance to the (so called) scientific treatments of...

As a professional gardener, I have encountered some beautiful and well structured soils in my time. As with most aspects of nature, there are plenty of mediocre and poor soils to maintain the overall balance. I’m not exaggerating to say that I’ve also brushed up against a few of these from time to time. From personal experience, I’m convinced that poor soils can be drastically improved with a degree of planning and effort. Having said that, I always suggest that beginners attempt to find the most suitable soil types for the plants they wish to grow. The ability to understand various descriptions of soil types depends upon some very basic understanding of soil texture and soil structure. When separated into its basic components, soil consists...