Soil Preparation for Planting Shrubs
There is little point in buying a shrub, whatever it may have cost, and then merely digging a hole that is large enough to take the roots, replacing thearound it and firming it in. The shrub will probably do reasonably well, but will do far better if the ground is better prepared for it. It ought to live for many years, considerably longer perhaps than the gardener himself, if it is properly dealt with from the very beginning.
As the branch system extends, so will the root system, so that, in order to allow free development, it is necessary to dig the garden soil widely and reasonably deeply. Double-digging, the cultivation of the soil to two spade-depths, is not often done these days, but it does pay to cultivate deeply on heavy soils and those which, after prolonged single-spit digging, have developed a hard pan below the surface, preventing freeand hindering the penetration of the roots. Clay soils are notoriously difficult in this respect for, although cultivation over a period of years may have made the top foot or so easier to work, below this there may be solid clay. Digging more deeply may be arduous, but is worth it in the long run.
Soils on the chalk formations vary widely. Some may have a deep chalky loam overlying the chalk, in others there may be a mere few inches of soil under which there is solid chalk. The former soils are easy to deal with, it is the thin types that present real problems. It is often necessary to compromise by breaking up the chalk below to a depth of a foot or so and as widely as possible, using, if necessary, a pick as well as a spade.
Sandy soils and those containing much peat present few problems as far as actual digging is concerned, but the former, in particular, tend to be so well drained that they retain little moisture in dry periods and plant foods tend to be washed down into them, out of the reach of roots. This is less likely to happen on the heavier soils. All soils benefit from having extra plant foods such asdug in while they are being prepared before shrubs are planted, but none so much as light, sandy soils. The object with these is to help them to retain moisture and to provide much-needed plant foods. Both can be obtained by digging in liberal quantities of humus-forming material. Moist peat helps to retain moisture, but contains little plant food and better materials are well-rotted garden compost, leaf-mould, made from fallen leaves rolled down in a heap.
Other plant matter that can be used is spent hops, old mushroom compost available in certain areas, shoddy, again available in places, or seaweed that is obtainable in coastal areas. Even rotted bracken fronds can be used since bracken is a common weed of sandy places. Failing all else, or where there is not sufficient other material, it is possible to rot down bales of straw, to be bought reasonably cheaply from farmers who have surplus stocks. The bales are broken up, sulphate of ammonia is scattered among them and the straw is thoroughly watered. It should rot down quite quickly to a dark brown material that can then be dug into the soil.
Farmyard manure is, of course, the best material of all, but so little of it is available, especially in suburban areas, that its use in liberal quantities on light soils can hardly be considered. Where it is available it may be used, mixed with compost, or by itself as a mulch or dug in, but it should be well-rotted. If it is fresh, it should be well down in the soil and not placed immediately around roots that may be scorched by it. It is better to use fresh farmyard manure to help to rot down other plant materials, or to stack it for a period until it has rotted down better. It helps to rot down straw very quickly if the manure and straw are thoroughly mixed together.
So, remember, soil preparation is of utmost importance when planting and growing shrubs, whether new or established but being replanted.