FEEDING THE FLOWER GARDEN

Otago Daily Times, Issue 22894, 30 May 1936, Page 7

FEEDING THE FLOWER GARDEN

A plant is built up, for the greater part, of some 10 to 14 elements (if you ve forgotten what they are ask your son who is doing chemistry). These it has to obtain from four different sources —the soil, the air, the water, or the gardener. Luckily for you—and the plants—the latter is, at the very outside, responsible for only three or four. These are, continuing to use the popular, and not the scientific, names, nitrogen, phosphates, potash, and, as the possible fourth, lime. With these exceptions, Nature provides everything necessary for a plant to live its normal life, even in such artificial conditions as exist' in the flower garden. Let us take a brief look at those which are left to us and consider their especial functions. Nitrogen is concerned, mostly, with the growth processes. It proves its presence by the development of luxuriant leaf and stem development. From this it will be clear that if a stunted appearance, with poor leaves of a sickly green, is noticed, a shortage of nitrogen is indicated. An excess of nitrogen must be avoided, as it produces a soft, sappy growth, subject to wind or rain damage and liable to attack by disease or pest. Nitrogen is supplied to gardefis in the form of nitrate of soda, the most readily available and, in consequence, the most easily lost by excessive watering, sulphate of ammonia, perhaps the most popular form, not immediately available to plants, but rapidly becoming available under the influence of microbial action, and, lastly, blood, the least readily available and, for that reason, especially useful for slowgrowing shrubs. There is a place for all three in the perfectly managed garden, for, when a plant needs a final " push "—as. for example, a week or two before the show blooms have to be cut, there is nothing like a spot of nitrate to put on that last extra polish. Ammonia must be regarded as the general stand by. It is used almost exclusively in the manufacture of “ complete mixtures ” and, in that form, it is safely useable at all times on all crops. The value of blood was indicated above. Broadly, it may be said that blood is useful during the dormant period of 'plants when only a small supply, becoming slowly available all _ the time, is requested to keep things moving. From the gardening point of view, the important effects of phosphates are on tbe germination and early development of seeds and seedlings, and on the development of strong root-systems. It tends, in contrast to nitrogen, to mature plants early. It is supplied to gardens, generally, in one of two forms, bonedust or superphosphate. The former corresponds in action and utility with blood (the two are usually supplied together as blood and bone), coming slowly into available form and thus supplying a small and steady amount of plant food over a long period. Its use may thus be taken as identical with that of blood. Super is a water soluble and immediately available form of phosphate, and, like ammonia, is used, almost always, as the basis of complete mixtures. There is little to be feared under normal conditions from an excess of phosphate. The functions of potash are many and varied.'- It exerts a very beneficial effect upon the development of young shoots and stems, preventing them from becoming too sappy, on the one hand, or too brittle on the other. In the leaves it is essential to the manufacture of those substances which control the development of the flowering and fruiting parts of the plant. It exerts a decidedly beneficial effect upon the colour of flowers. It is especially valuable to roses, and also to bulbs, for which plants its colour effect is most marked. Finally, by improving the general constitution of plants, it enables them to withstand more effectively tbe attacks of fungus disease. Its most interesting feature is its relationship of nitrogen. It may be said broadly that whenever there is any danger of some ill-effect from excess nitrogen, it can be averted by the use of an equivalent amount of potash. The importance of this will be clear. You must use a lot of nitrogen, in order to get vigorous growth: this gives some cause for fear of overgrown, sappy individuals, so you must use a lot of potash with the nitrogen to stiffen up the <--owth that is produced. It is something like the Scottish recipe for whisky-and-soda, “ Fiftyfifty . . . and plenty of soda.” Potash is available either as muriate or sulphate of potash* Whilst the latter is, perhaps, rather better known amongst gardeners, there is little to choose between them for most purposes, and muriate, being rather cheaper, is nowadays more frequently need in mixtures. Both are completely water soluble and so readily available, but they do not wash out of the soil, being held in a state in which they are “ready when called for.” As with phosphate, there is no need to fear any harm from a possible excess of potash.—The Australian Garden Lover.