The permanent beauty of flowering shrubs should not be overlooked; indeed, in many gardens they provide much of the colour. As they do not need the continual attention which is necessary to keep formal flower beds looking their best, many gardeners are apt to feel that once planted shrubs can look after themselves. This is a mistake. Flowering shrubs need occasional pruning, mulching, compost and fertilizers, if their beauty is to be seen to the full.
In this chapter we will deal with their planting and maintenance only; methods of propagation by cuttings, etc., are dealt with in a later chapter.
New flowering shrubs are normally planted at the onset of the rains and planting should not be delayed beyond when the rains have set in steadily, so that the shrubs have a chance to become established in their new positions before the rain is too heavy. This is very important and must be borne in mind, particularly in areas where rainfall is heavy yet falls in only a few months of the year.
Well before the planting season commences the places for the new specimens should be well considered, and consideration should be given too to the shape, flower colour and foliage of any surrounding plants. Dig the holes for the new plants at least two months beforehand so that the manure and good topsoil with which they are filled has time to settle before the actual planting. The size of the holes depends largely on the type of soil. In a good fertile loamy soil, holes 2 feet square and 2 feet deep will be adequate for most shrubs. In sandy and shallow soils where more organic matter must be provided if good results are to be obtained, the holes should be 3 feet square and 3 feet deep. When the holes have been made, the bottom should be forked over, and this may have to be done with a pick or crowbar if the subsoil is very compacted. In areas where there are likely to be very heavy rainstorms, this last is most important, since even when the holes are filled they will still act as sumps for the surrounding land and the plants will not like having their roots continually in water and will die off.
When refilling the holes, do not replace the subsoil which has been removed, but fill with topsoil taken from elsewhere in the garden, together with an equal part of well-rotted compost or animal manure. If dried leaves or leaf mould is available, first put a layer at the bottom of the hole; it will provide further organic matter for the plant to draw on later in the year. After filling, mulch the surface and push in a stick to mark the centre of the hole.
Plant, of course, on a dull or rainy day. If the plants have been grown in clay or bamboo pots or baskets, they should be well watered a few hours before transplanting to make the soil stick to the roots and protect as much as possible the delicate root hairs.
When the plants are ready to be planted, scoop a hole out of the place where the original hole was made, slightly larger than the pot in which they were grown but no deeper. Do not attempt to dig the plant out of the pot. If it is a small one, remove the plant by turning it upside down and tapping on the bottom; if it is a shallow local clay pot, turn it on its side and roll it, taking care that none of the soil falls away. Split bamboo pots in two with a knife, again taking care not to damage the roots.
Plant the shrub into the prepared hole, but see that the stem is not covered any higher than when it was originally growing in the pot. Firm the soil round it so that there is no possibility of movement. Finally mulch around the plant, but leave clear a space of 2 inches round the stem or insects, especially white ants, may attack the lower part of the stem. Until the plant has established itself in its new position, it should be watered fairly frequently.
If a larger shrub has to be moved from one position to another, dig round it to a depth of between 6 to 8 inches a week before it is to be moved. This will give the roots time to form into a ball and a lot of soil will be able to be moved with the plant. How far this digging is done from the central stem depends upon the size of the plant. For small shrubs up to 3 feet, dig in a 1-foot radius from the stem, increasing this distance with the size of the shrub. Hold the spade vertically and press in to the required depth, push inwards towards the plant and then remove cleanly. If any soil sticks to the blade of the spade—as it will do in clay soils—move the spade backwards and forwards slightly until it can be removed cleanly. The whole object of the operation is not to remove soil. Carry on in this way all round the plant. A week later it will be possible to remove both soil and root, after it has been watered gently, without disturbing the soil. It is not advisable to try to remove a large shrub by yourself—it needs two or three people. It is usual to prune back large shrubs before moving them. The removal of many of the leaves helps the plant in that it does not lose moisture through transpiration during the time it is unable to replenish it with new supplies from the soil. Do not prune more than necessary—usually a few inches off the ends of the shoots will suffice. If the shrub has a bad form, this is a good time to shape it nicely.
Mulching will help shrubs to withstand the dry season and particular care should be taken in this respect at the end of the rainy season.
It is best to give a top dressing of compost and fertiliser at the beginning of the rains, when the plants will begin to put on a new flush. Never apply compost and fertiliser at the end of the rains, as a new flush of growth may be produced which cannot be supported through the dry season from lack of water. But good mixed fertiliser spread in a ring round the shrub in the middle of the rains will usually be beneficial. When applying fertiliser, a good rule is that the larger the shrub the further away from the stem should the fertiliser be applied. As a guide, apply fertiliser a foot away from a shrub 3 feet high.