The best information that anyone can give you is “fertilise less, more often” rather than “fertilise more, less often”. As a Golf course superintendent I can attest to the advice of “less, more often” especially for the home owner or gardener. The application recommendations for the gardener printed on the fertiliser bag, or box, is a general application rate and unless you have a high costing applicator, are extremely and painstakingly precise, the chances are that you will either over apply, or under apply.

I am constantly asked to consult on lawns, and the obvious signs of incorrect fertiliser application, is the first problem. What are the requirements of a plant? Good soil for growth, enough good quality water, and the plants nutritional necessities. A plant, although needing all nutrients in differing quantities, requires Nitrogen (N) and Potassium (K) the most, so the gardener will normally apply a fertilizer high in both elements. Nitrogen is the basic element of color and root to shoot growth, as well as influencing plant disease susceptibility. Potassium is important in various physiological processes, photosynthesis, the metabolism of carbohydrate and protein, an enzymes activator,adjusting stomatal openings and water relations.

However over application of Nitrogen, either in the form of Lime Ammonium Nitrate (L.A.N.) or a urea based fertiliser, will scorch the root system, and inhibit the uptake of water and other nutrients. This results in the death of the plant or the setting back until the excessive nitrogen is leached out of the root zone. Heavy watering of the soils accelerates the leaching process, to return to normality of the lawn.

Lets look to the scenario, of a hand application of fertilizer. It is impossible to accurately apply the fertiliser evenly over the total area by hand, and the result will be peaks and troughs of fertiliser rates. The areas over fertilised are going to grow faster and be of a differing color to that, that has received less. If slight burning occurs, over watering is the normal practice to leach out the excess, but what will happen to the area that received less, where the same leaching will take place? Answer, a quick return to a retardation in growth, under-activity, and a lighter colored grass. This will then be interspersed with a darker, quicker growing and lush grass, resulting in a poor visual uniformity of the lawn.

Applying the fertilizer at a half, or less recommended rate, and the lawn watered, the grass will not depict a large variance in colour or growth, and the chances of over fertilization and the resultant burning will be avoided entirely. The lower applications should be applied more often, and the required grass growth and color attained more quickly, allowing for a better controlled attainment of the required visual look of the lawn.

So a “less, more often” rather than a “more, less often” attitude must be followed. The pleasure attained from having a good, visually healthy grass, will be the rewarding result.