Planting and Pruning Shrubs

Preparing Soil for Shrubs

If the soil is not particularly good, you will need to improve it. Dry, sandy soil will retain water much better if you work in organic material such as compost or garden peat; compost also provides extra nutrients. Clay and other soils which are difficult to work can be improved by adding sand, compost or garden peat.

Dig the soil over well before planting: two spits deep is normally enough. Place some manure, leaf mold and, if necessary, lime in the hole. Always plunge the root ball in water before you plant a shrub.

Generally speaking, when designing a garden the taller shrubs should go at the back, moving down through medium to small ones in the foreground. You will need to take account not only of the shrub’s height, but also its spread, which may become considerable over the years. To work out the planting distance when planting two shrubs together, add the totals of their mature heights and divide the result by three. You will also need to bear in mind that the height and spread given for the shrubs may take many years to reach.

Shrubs can be used on their own, combined to form hedges, or used as ground cover, which helps to keep down weeds. They can also be very attractively combined with perennials.

Taller deciduous shrubs lend themselves well to underplanting with bulbs, and ground-covering shrubs also set off slightly taller bulbs very well.

Twigs of flowering, evergreen and/or fruiting shrubs such as syringa, magnolia or hazel can also be used in indoor flower arrangements.

Planting Techniques for Different Shrub Types

If container-grown or balled plants are obtained, it is only necessary to prepare a hole just a little larger than the container and slip the plant into this with as little root disturbance as possible. Pot-grown plants can usually be tapped out quite safely by turning them upside down and rapping the rim of the pot sharply on something firm, such as the handle of a spade thrust well into the soil. Of course the plant itself must be carefully held while this is done so that it does not fall to the ground and possibly snap off. In the case of balled plants and those grown in polythene bags, the covering material can usually be cut and then stripped off with the plant on the edge of, or actually in, the hole it is to occupy. But whatever the precise method used, the covering must come off unless it is only of paper or compressed peat or some other substance that will rot away in the soil.

With bare root plants a little more thought and care are necessary. The hole made must be large enough to ensure that there is space for all the roots to be naturally disposed, with room at the top for a covering of 1 or 2 in. of soil over the uppermost roots. Another way to determine depth is to look for the dark soil mark on the stem or stems, indicating where the soil came to in the nursery bed, and to replant so that this is just beneath the surface. With bare root plants it is also necessary to work soil around and between the roots and to make this easy it often pays to prepare in advance a planting mixture of well-broken soil mixed with about a third its bulk of peat and containing a sprinkling of bonemeal.

Aftercare for Newly Planted Shrubs

Whatever type of plant is being used, once the soil has been returned around and over the roots it should be made thoroughly firm by pressing all round with the foot, after which a little loose soil or peat can be scattered over the soil to leave everything tidy.

Shelter

Some shrubs, particularly evergreens, may require some shelter from wind or sun for a few months after planting until they are well established and able to look after themselves. Large plastic bags of the type used for fertilizers, composts and peat make excellent shelters if slit top and bottom and then slipped over the shrub and held open with three or four canes. Hessian screens can be made in a similar way or quite effective temporary shelter can be given by thrusting evergreen boughs into the soil around the newly planted shrubs.

Pruning

Not many shrubs require pruning immediately after planting, though it always pays to cut out damaged stems or any that appear so badly placed as to upset the balance of the specimen. Some hedge shrubs, notably privet and lonicera, will repay immediate shortening to ensure that they branch freely right from the base, but it is not until later years that pruning becomes a serious problem.

Basically pruning has four aims: the first to prevent plants from growing too large; the second to get rid of diseased or decrepit growth; the third to improve the natural appearance of the plant by removing badly placed or overcrowded stems and the fourth to improve the quality of the flowers or leaves.

Often the steps taken to achieve one of these ends also look after some of the others as well. Thus it is always wise to start by removing obviously diseased, damaged or weak growth, because when this has been done the specimen may look very different and require little further pruning. If it does appear that something more is needed, thinning out overcrowded, crossing branches may put things right.

A few shrubs, particularly those that flower in summer such as the purple buddleia, the varieties of Hydrangea paniculate, fuchsia and caryopteris, can be cut hard back each spring with considerable benefit to the quality of their flowers and without destroying their natural habitat. Some spring and early summer-flowering kinds, such as forsythia, weigela, philadelphus and cytisus, can have most of their flowering growth removed immediately the flowers fade, and this can be a convenient way of restricting their size and improving the quality of their flowers at one and the same time.