There are two main groups of fertilizers: organic and inorganic. The organic types can be rotted garden compost, manure, dried blood, bone meal or fish meal. Organic fertilizers are usually activated by bacteria and work more slowly than inorganic ones. Inorganic fertilizers sold under brand names are mostly synthetic or mined and normally come already mixed in various strengths. They are cleaner to use and therefore better suited to the indoor gardener.
Different Forms of fertilizer
Fertilizers are available in a variety of forms from liquid to tablet form. Here are some of the different types and the way in which they should be used.
Liquid feed
The most popular kind and, indeed the best selling, is liquid feed. The advantages are immediately obvious. It is clean, easily administered and economical. The instructions on the bottle usually tell you how manydrops of feed to add to a given quantity of water. There are several brands on the market, but the most widely known is not necessarily the best for every plant, as the proportions of the ingredients vary slightly.
Foliar feeds
Another kind of liquid feed which is currently popular is foliar feed. It is sprayed on with a mister and the feed is absorbed through the plant’s leaves. For maximum effect it should be applied regularly during the growing season and used in addition to regular root and compost feeding. Do not rely on foliar feeds as the main source of nutrition.
Dry feed
There are also dry fertilizers, some of which are spread by hand on the top of the pot. These are particularly advantageous for large plants or mixed beds where a slow rate of absorption is required. Some of the other dry fertilizers are dissolved in water and administered like the liquid feeds. These dry feeds are very good, but more care must be taken to dilute them correctly according to the manufacturer’s instructions.
Tablets
Lastly, but by no means least, a recent revival is the fertilizer tablet or stick that is pushed into the top of the soil or compost in the pot. This tablet or stick works on the principle that the fertilizer is slowly discharged by the addition of water. The plant gets a regular supply of food over a long period as you water.
Points to remember when feeding
All plants havea resting period when they quite naturally stop growing. Later there is also a dormant period with no growth, when the leaves fall off orthe top growth dies down. Usually, though notalways, thisoccurs in winterand plantsshould not be fed. It is during the growing season, generally from March to October, that plants should be fed to encourage new growth.
When using fertilizers, always make sure to follow the makers’ instructions. If anything, be on the mean side. Overfeeding can easily damage the roots. Remember never to feed a plant after repotting. The new compost should contain enough fertilizer to last about six to eight weeks. Even then no fertilizer should be given if the plant is dormant.
It is a good idea to change your brand from time to time. The slightly differing proportions of the ingredients in another fertilizer may compensate for anything that might be lacking in the one you have been using.