POTTING AND SEED SOWING

Wairarapa Times-Age, 29 December 1939, Page 3

POTTING AND SEED SOWING

THE NECESSARY COMPOSTS. Though this is not the main time for potting and seed sowing, there is always some to do, and this is a good time to lay in supplies of the necessary composts. Soil and manures may be said to be the raw material from which plants are manufactured, and the successful results depend largely on the nature of the raw materials.

The basis of all potting and seed sowing soils is loam, this consisting of a certain proportion of clay, silt, and sand. When clay predominates it is said to be a heavy or clay loam, and when sand predominates, it is said to be a light or sandy loam. The correct proportions are about half and half. The usual loam recommended is turfy (the top four to four inches and a-half of an old pasture). This is cut into sods about 12 inches by 9 inches and stacked in a heap with the grass side downwards for several months or until the grass roots die. Should the soil be poor, it is often recommended to put a layer of well-rotted stable or cow manure between each layer of sods. Should the turf be very dry, it should be watered and if very wet it should be stacked so that the rain will run oil’. Though turfy loam is usually recommended, it is not essential, and good garden or field loam when mixed with suitable opening substances will do. The advantage of the grass roots is that they add a certain amount of organic matter to the soil,

and they help to keep it open and thereby assist drainage. By using the right form of humus and the right amount of sand, however, fibre can be dispensed with entirely, without any loss of physical condition. The ideal loam, then, is a medium one with or without fibre. Should this not be obtainable. the gardener need not worry, since if the recommendations made later are followed the quality of the loam is not such a vital factor and good results can be obtained with lighter loams not of the highest quality. Humus. There are three sources of humus: leafmould, heath peat and bog peat. Of these three, leafmould is the most suitable though its quality also depends on the kind of leaves collected —beech and oak are considered to be the best. It usually contains weed seeds, worms, and may introduce disease, unless it is sterilised or properly rotted. As a rule the leaves should lie for a year in a heap before they are turned over. In a short time the mould is ready for use. Being able to get plenty of leafmould I have not used peat, but I daresay that that obtained from bogs when dried and crumbly would be suitable. It is said that peats are definitely superior to leafmould, which soon rots away and has much poorer moisture holding capacities. Sand. Sand is added to composts to improve their physical condition and ensure good drainage. It should be clean and sharp, and free from humus, silt, lime, etc, and should grade evenly from fine to coarse particles. The yellow sand we get often contains too much clay, and it should be washed and dried before it is used. Beach sand is too fine to be used by itself, though it can be mixed with coarse sand, and is useful for opening up heavy soils in the open garden. Compost. The essential of a good compost is that it should be in correct physical or mechanical condition, and for seed sowing this is more important than its chemical composition. It should be well aerated, of good texture, having good moisture holding capacity and draining freely. Most loams when used alone are too close in texture and too cold when used for seed sowing or potting. There is not enough air in them, their moisture holding capacity is bad. they become wet and sticky after watering and are apt to dry out too rapidly, leaving a hard and cracked surface. The mixing of loam, peat or leafmould, and sand in the right proportions 'is of vital importance to many plants, and bad germination, poor growth and clamping off are often the result of neglect in mixing the compost in the correct proportions. For seed sowing, it is usual to use the same mixture for all, the only difference being the degree of fineness to which the compost is reduced by riddling. For the larger seeds such as those of the pea. bean, and pine types, a half-inch sieve is fine enough, but for such small seeds as begonias. I gloxinias and streptoenrpus a very fine sieve is necessary.

For potting the various kinds of plants it is also found that a stock mixture will suit practically everything, though the addition of wood ashes and crushed charcoal may be an advantage for some. The John Tunis Institute has been experimenting with several mixtures and as a result of these experiments on a large scale they recommend the following for private, public and commercial gardens:—Seed sowing: Two parts by bulk of medium loam, one part leafmould or peat and one part sand. Potting: Seven parts by bulk of medium loam, three parts peat or leafmould and two parts coarse sand. These should of course be sterilised and mixed for several weeks before use.