Garden Borders and Beds: Size and Aspect
THE NARROW BORDER
As conventional borders face one way only, aspect is very important, especially if the backing is taller than most plants are likely to grow. Since most hardy perennials are sun-loving plants, choose a position facing more or less south. If only a northerly-facing border is possible it could be filled with plants that prefer shade. There is a sufficiently wide range to choose from, but these may be more difficult to obtain as most nurserymen tend to stock only the more popular sun-loving varieties.
Another factor to consider is wind, particularly the sudden storm or gale in early summer which can play havoc with plants. A border sited along what might prove to be a funnel for strong winds — such as an east-west opening between buildings or a screen of trees or ever-greens — needs more staking than a border in either a completely open or a completely sheltered position. Far less staking is needed if island beds are used for perennials.
HEIGHTS OF PLANTS
If only a narrow strip is available select plants accordingly, making allowance for whatever serves as a backing.
A hedge demands more space than a wall or fence, and some hedges, as well as spreading above the ground, have voracious roots that can take nutriment and moisture from 3 ft. or more on either side. On a light, sandyespecially, a hedge will affect the border plants during a dry spell, so that, depending on the size or vigour of the hedge, 2 ft. might have to be allowed in a 5-ft. border, thus reducing the effective width to only 3 ft. when the time comes for planting.
A fence or wall is harmful only in its drawing or weakening effect on plant growth. Plants that are taller than a foot or two naturally lean away from any kind of backing as they run up to flower, and the closer they are planted to the backing the more they will lean. Take this factor into account when gauging the effective width of a border.
Dwarf plants look better than tall kinds in a narrow border.
A safe guide is to limit the selection of plants to those whose height is half the effective width of the border. For example, if the effective width of the border is 6 ft., it should contain nothing taller than varieties which grow to only 3 ft. Apply this ratio to all borders less than 12 ft. wide and place the plants in order of height, with the shorter-growing ones in front.
Island borders or beds are those that can be approached and viewed more or less all round. Growing hardy perennials in island beds is most satisfactory as it is more in keeping with their natural requirements, light and air are not restricted, growth is therefore stronger, and normal height is maintained. Given adequate spacing and reasonable planning, perfection can be attained with the least effort and maintenance, and the fact that the beds can be viewed from all sides adds greatly to the charm. If mainly straight lines exist in the garden, a formal shape, such as oblong or oval, is best. But introduce informal shapes if these will fit in with the surrounding trees and shrubs. An island bed sometimes fits in perfectly with a group of shrubs, such as a promontory into a lawn, with only a narrow path between the shrubs and the plants in the bed.
Island beds and conventional borders can be made to almost any scale. While they can be any length that is convenient, width should be limited to 30 ft. to allow access for maintenance.
Midget beds or borders, which can be as little as 5 ft. wide, offer considerable scope to those with. Many hardy perennials are normally seen only in , but they can be used as frontal groups in small beds. With heights ranging from 6 in. to 2-½ ft. in a bed or border about 5 ft. wide, the effect can be both varied and very charming.
THE MIXED BORDER
It is possible to select perennials not only for different soils and situations, for flowering at required periods and for cutting, but for fragrance, for flowers attractive to bees and for silver or grey variegated foliage.
Some plants will merge quite well with certain shrubs but should be chosen carefully. There is a fairly wide range of perennials available to plant asbetween flowering shrubs or trees. Some, especially those with an overall symmetry or stateliness, such as kniphofias and heucheras, look well between or in front of shrubs, but indiscriminate planting will result in harmful competition for light, space and nutriment.
IMPROVING AN EXISTING BORDER
Borders that were irrationally planned in the first place and which have since deteriorated can usually be improved. Very often the cause of trouble is that the border is too narrow for the tall plants it contains; that competition from trees, shrubs or a backing hedge is too fierce; or that light and air are restricted. The remedy may be simply to take out over-tall plants and replace them with others of lower stature; but the border may need a complete overhaul, with thorough digging and manuring, using again only those plants that are adaptable to the site, and making up with fresh and more suitable kinds. If possible, increase the width of a too-narrow border. If it adjoins a lawn, take in part of the lawn and dig in the turf, as this adds richness to the soil. When converting grass, whether lawn or rough, for plant cultivation, chop it up, dig in the top 1 or 4 in. of chopped turf, and cover with 10 to 12 in. of soil taken from below the turf so that the grass will not grow through.
If the only means of widening a border is by digging up a gravel path, this can be done quite successfully. Often a path that runs between the border and the lawn is not really necessary as the lawn itself provides suitable access. In many instances it would be far more rewarding to have a strip for access at the back of the border, between the tallest plants and the backing hedge or wall. This would also overcome the problem of plants growing too close to the backing. Provided the effective width is more than 8 ft., low-growing, early-flowering plants, such as Veronica gentianoides, could be grown in the front of this path, and would show to real advantage before the plants in the border itself grew tall enough to hide them from view. Arrange access by stepping-stones made from bricks or pieces of paving. A good maximum width for a one-sided border is 15 ft., with a rear strip in addition to provide access for maintenance work. With this width no height restrictions apply, but careful planning is necessary.