POTTING COMPOSTS

Wairarapa Times-Age, 7 August 1940, Page 3

POTTING COMPOSTS

PREPARATION IMPORTANT. The preparation of potting composts is every bit as important, as those for seed sowing and. while turfy loam is the most desirabla, good garden soil is quite suitable provided the correct quantities of peat or leafmould and sand are added to obtain the necessary physical texture. The advantage of turfy loam is that the grass roots which are dead and decaying help to keep the compost open, securing good drainage, and as they decay they yield up useful food materials to the plants. Leafmould’ or peat act in the same way keeping the compost open, enabling it to retain water and soluble plant food and the sand assists in the drainage. Lcafmould. however, should not be too completely rotted down, the flakey kind is the best for it the leaves retain something of their original shape while still being in a condition for pasing through a half-inch sieve.

The following characteristics of a good compost are:—

1. Il should be in good physical condition, i.e., it should possess a crumply structure and permit the entry of air and be able to hold sufficient moisture while permitting excess to drain away.

2. It. should provide an adequate and balanced food supply for the plant at all stages of its growth. 3. It should be free from all harmful organisms and substances.

While sterilisation is not so imporltant as in the case of seed sowing it is a distinct advantage if some form of sterilisation is carried out.

At one time gardeners considered that every kind of pot plant required a difl'erent soil mixture, and some of them wore very complicated. Now it has been proved by experiment that one standard soil mixture is all that is necessary, and if at any stage of the development of the plant some additional feeding is necessary it can be applied in the liquid or powdered form.

A. standard potting compost should consist of seven parts by loose bulk of medium loam, three parts flaky leafmculd and two parts coarse clean sand. To each bushel of this mixture should be added an ounce and a-half of coarse bone dust, an ounce and a-half superphosphate. three-quarters of an ounce sulphate of potash, three-quarters of an ounce of ground lime. This mixture should be prepared at least a fortnight before it is required and a quantity can be prepared and stored in a dry shed for use as required.

Cleanliness should be secured at all times; all pots should be washed inside and cut; crocks should also be washed, and a supply of sphagnum moss or fairly fresh leaves should be at hand for covering the crocks. The amount of moss will vary with the size of the pot and the length of time the plant is to occupy it. One good piece will be •ufficient for a three or four-inch pot for a bedding geranium, but for foliage . lants. chrysanthemums and tuberous begonias which are some lime in their (lowering pots a large piece should be placed over the hole in pot. with the hollow side down; over this some smeller pieces should be placed and on top of all some moss leaves, or rough turf to prevent the soil from washing down among the crocks anti blocking them up.

In every case over-potting should be avoided, for plants do much better when in pots of a reasonable size and u shift of from a 3in to a aim from a 4in to a Gin. and from a sin to a Tin or j Sin is quite enough. i When potting on a palm, aspidistra, fern or other foliage plant put a little I of the compost in the bottom of the, pot. and make it firm, then turn the plant, to be potted out. remove al! the crocks, and any surface soil in which there are no roots, and tease out the roots a little with a pointed stick. Fit the plant into the new pot, keeping the top of the ball ol rpots about an inch below the rim. fill in with soil among I he ball of roots, with an old label or potting stick. Finish oil' the' surface evenly and firmly, allowing about : ;in to '.in below the rim for a Gin pot and more for a large one. There should be sufficient space to hold enough water I to completely saturate the soil when watering. Alter potting give < iy> good watering, but this operation will have Ito be done with great, care al terwards until the roots pentrate the new soil. I but overhead spraying can bo done | regularly except on cold, wot or frosty ' days-.