Garden Fertilizers – The Changing Scene
The changing fertilizer scene
The fertilizer scene has changed a great deal in recent years as gardeners have become more knowledgable on the vital issues surrounding plant nutrition. In addition there is increasing enthusiasm for organic growing methods. Most well stocked garden centres these days carry a reasonable range of products. It cannot be stressed too strongly, however, to avoid becoming caught up in what could be called a “chemical syndrome” — when every nuance exhibited by the growing plant sets off a warning bell — and the gardener rushes to try and alleviate the trouble by applying another chemical. Variance in plant performance can be due to many circumstances, of which chemical imbalance is merely one, and there must always be some compromise.
Fertilizers for greenhouse culture
Most fertilizers are now sold in kilograms (kg). In round figures, 50kg = 1cwt.
Other equivalents you may find useful are:
1oz/sq yd = 28g/sq yd
= 34g/sq metre (m2)
Important note: There are many proprietary liquid feeds. Use as directed. It is important to check up on the levels of nitrogen, phosphorus and potash, and the balance of these elements to each other in relation to the crop being grown., for example, relish high potash feeds for the early part of the season, whereas require higher nitrogen.
Natural or artificial?
There is often a dilemma in gardeners’ minds whether they are using natural or artificial chemicals — especially if they are of the organic turn of mind. Organic gardeners do, of course, lay much stress on the use of organically derived materials such as animal manures and garden composts, along with seaweed in natural, meal or calcified form. Then, of course, there are the well known materials such as Bone Meal, Dried Blood, Fish Meal, Hoof and Horn Meal, plus less well known chemicals such as Rock Phosphates and Rock Potash — which are all natural materials — provided they are not contaminated in any way.
There are also materials like wood ash, soot, sewage sludge, municipal compost, and of these there can be doubts about sewage sludge (from the disease angle) and municipal compost (for its heavy metal content). Lime is, of course, readily available as ground limestone and is a natural material.
The use of liquefied seaweed offers an excellent organic source of macro and micro-elements in readily available form. One such is marketed by Maxicrop, and is very popular with organic gardeners. It has a wide range of uses, including straw bale treatment forand cucumbers. A special feature of seaweed-based liquid feeds is that they contain the complete spectrum of nutrient content. An increase in pest and disease resistance is thought to be an important feature of seaweed-based fertilizers.