Long nights and short days are the order of the day for the next couple of months, a good time to expand your knowledge on what you normally do, without much thought, throughout the year.

Use chemicals! Chemicals are used in pesticides, fungicides, nematicides, herbicides all of which are used to control insects, fungal problems, nematodes and weed control, the latter often being the primary host for the others. Healthy plants usually show more resistance to the first three problems, and healthy plants are plants that receive sufficient quantities of plant nutrients to develop (healthy) growth, and encourage weed growth.

It is to this category of chemicals that I will expand upon, by explaining the often-arcane language that surrounds a simple bag of fertiliser. All chemicals are given an elemental symbol that denotes the active chemical being discussed as for example a bag containing a mix of N.P.K. means the elements nitrogen, phosphorus and potassium. These are sixteen elements that have been determined to be essential for plant growth and reproduction; these essential plant food elements come from air, water, soil and fertilisers. From air and water, carbon, hydrogen, oxygen and nitrogen with ninety to ninety five plant substance being comprised of these elements.

From soil and fertilisers the major or primary nutrients are; nitrogen (N), phosphorous (P), potassium (K); the secondary nutrients being, calcium (C), magnesium (Mg), sulphur (S); micro nutrients are iron (Fe), boron (B), manganese (Mn), copper (Cu), zinc (Zn), molybdenum (Mo) and chlorine (C1).

The primary or major plant nutrients are needed by plants in large amounts, whereas, secondary nutrients and especially the micronutrients are required by plants in very small quantities. A brief summary of each element may assist in understanding their importance in the growth of healthy plants.

Nitrogen plays an important role in plant life, as it is an indispensable part of proteins, chlorophyll, amino acids enzymes and vitamins. Nitrogen deficiency exhibits restricted growth, fewer stems and yellowing of older foliage. Phosphorous exists in the soil in many forms, both as organic and inorganic compounds; it is also added to the soil in manure and fertilisers in a variety of materials. Phosphates undergo many changes in soils both by organisms and by purely chemical reactions. Deficiencies include thin growth, fewer stems and marginal scorch on leaves.

Potassium is widely distributed in soil minerals, with heavy soils containing higher amounts than lighter soils. Potassium deficiency shows growth that is squat and bushy, leaflets can be bluish green, slight intervenal chlorosis, marginal scorch and brown spots on under surface.

Secondary elements that can cause problems in Bermuda include magnesium, which is easily leached from sandy soils, and is therefore an essential element in many local fertilisers for lawns and flowerbeds. Iron is present in quantity in most soil, mainly in the form of oxides. The availability of iron to plants increases with acidity; hence in Bermuda problems often occur. Sulphur is used on Bermuda lawns to reduce the ph or alkaline to acid balance.

Organic Fertilisers

It is a well-recognised principle that plants are able to absorb nutrients only as they are dissolved in water. Therefore, the fertiliser value of organic materials depends on their decomposition, as well as the amounts of nutrients present in the materials. Nitrogen is the primary nutrient of importance in organic materials. Organic materials used for fertilisers fall into two groups, i.e., natural substances and those produced synthetically. Natural substances include, animal manure, sewage sludge, composts, leaf mould and combinations of same mixed with shredded horticultural waste. All materials should be of a friable nature and aged in its decomposition, before being used as a mulch or in planting holes. Only fine sifted material should be considered for top dressing lawns.

Synthetic materials are manufactured by treating urea (a nitrogen based fertiliser) with different amounts of formaldehyde. For ureaform nitrogen fertilisers, it is necessary not only to have information on the total nitrogen content, but also to know what proportions are readily available (soluble) and what proportions are slowly available.

One often finds technical terms written on bags of fertiliser, manure etc., which to the layman can be confusing; an explanation of some of these terms follows. Commercial fertiliser was originally given this name to distinguish it from animal manure and other natural substances, such as sewage sludge, seed meals etc. In general they are composed of inorganic chemical substances or mixtures carrying nitrogen, phosphorous and potassium.

Mineral fertilisers are the chemical compounds that carry essential plant nutrients. For nitrogen they are principally nitrate or ammonium compounds; for phosphorous it is usually a rock phosphate treated with acid, and for potassium the active ingredients are derived from either potassium chloride or potassium sulphate.

Organic fertilisers are those of plant and animal origin such as sewage sludge, manure etc. Soil humus is the name given to partially decomposed plant and animal remains in the soil. Microbes are a general term used to include all small organisms that can be seen only with a microscope. They live in a thin film of water surrounding soil particles and granules and are active in decomposing all kinds of organic substances.

Fertiliser to plants is like food to man, without enough of the correct amounts and types they will suffer, look sickly, not grow to their best and in some cases die. This applies to flower beds, lawns and vegetables gardens, just because it 'looks green' does not mean it is healthy; makes a new years resolution to either feed the grounds yourself, or have it incorporated in your landscape contract.

Your efforts will certainly be appreciated, and the habit could well grow on you.