THE IMPORTANCE OF SAND TO PLANT RAISERS

Evening Star, Issue 20636, 8 November 1930, Page 26

THE IMPORTANCE OF SAND TO PLANT RAISERS

Silver sand plays an important part in successful plant cultivation. It is used chiefly as an ingredient of potting soils, in which its action is purely mechanical; that is to say, it does not supply food to the plants, but assists in aerating the soil by keeping it open. For this purpose it must be coarsegrained, so that Avhen incorporated thoroughly with the compost it prevents it from coagulating into a solid mass into Avhich air Avbuld haA'o difficulty in penetrating (writes Leonard Griffiths in the ‘ Hawke’s Bay Tribune ’). The amount of sand used in the compost for seed-sowing depends on the size and typo of seeds. Seeds of begonia, gloxiana, gentian, and lobelia, which are sloav in germinating, require one-quarter of the bulk of silver sand, whilst antirrhinum, alyssnm, coleoua, etc., which germinate- quickly, require only half that amount.

The quantity of sand used in potting composts also varies. Fine-rooted plants, such as erica, stroptocarpns, and primula require about one-eighth part of sand, Avhereas half that amount is sufficient for coleus, geranium, fuchsia, heliotrope, and similar plants with vigorous root systems. ' Sand is, in many cases, the only covering used for seeds sown in pots. The tiny seeds of begonia, streptocarpus, gloxinia, and lobelia germinate better, with only a slight covering of sand. . After potting a thin layer of silver sand may be sprinkled on the surface of the compost. This prevents it from consolidating, and cheeks the growth of moss and similar groavtlis which tend to sour the soil.

For striking cuttings there is nothing more effectiA-e than silver sand. It has, hoAvever, the disadvantage of drying out-too rapidly, so that it is the general rule to use two parts sand to one part linely-sifted compost. When sowing small seeds it facilitates even distribution if they are mixed beforehand Avith five times their oavu bulk of fine sand. _ Finally, sand is used largely for mixing avith fertilisers to ensure that they can be spread evenly over a certain area. Equal quantities sulphate of ammonia - and sand are mixed and applied to the laAvn as a tonic. The former supplies nitrates, which are essential for healthy plant growth, and the stand ensures more equal distribution.