Planting and Maintaining Hedges
North Coast Hedge Types
Many different kinds of shrubs (and trees) can be used for hedges, depending on the effect you are after. There are low hedges and tall, evergreen and deciduous, clipped and informally natural. Hedges may be used to guide traffic, to delineate, to screen an undesirable view, or to lessen that nagging afternoon wind that cools our Humboldt gardens.
The main requirements for selecting shrubs are good-looking, dense, healthy foliage and, if they are to be pruned to a certain height or shape, a toleration of continued clipping.
The easiest hedges to maintain are those allowed to keep their normal shape. In other words, you should choose shrubs which, when mature, have the desired height, width, and appearance, with almost no pruning. Of course, they have a rather billowy look instead of being rigidly trim, but in many situations this is preferable, or at least desirably attractive.
Sometimes a flowering hedge is desirable. Such plants may be pruned periodically, perhaps once a year, but allowed to grow in their natural informal shape rather than in a sheared unnatural form. Examples would include Spirea, Honeysuckle, Wisteria, Viburnum and Roses.
Deciduous hedges generally provide screening only during the growing season. However, some types, if pruned severely over a period of time, will form a dense tangle of twigs which provide a fair winter screen.
Evergreens, both broad and narrow-leaved types, are effective year-round hedges since they remain beautiful even in winter. Planting time is the same as for shrubs used for other purposes.
How Many Plants Do I Need?
When shopping, remember that you do not need the biggest, most shapely, and thus the most expensive specimens. Since hedge plants are grown to become interlocking masses of foliage, you can start with small-size plants. Often in mail-order catalogues, and also in magazine ads, you will find hedge plants marketed in units of 12, 25 or 50. The bigger their root systems, the better; and while husky small plants grow rapidly and vigorously, those slightly larger and bushier with more roots will give quicker results.
The number of plants to buy is figured on the basis of the size the shrubs attain when mature. But since your goal is not specimen bushes but dense, overlapping growth, multiply your count by 2. Plan to space the plants accordingly. Typical hedges, such as privet and barberry, are usually spaced 12 to 18 inches apart. An Escallonia hedge may have the plants spaced at three- or four-foot centers.
Keep in mind the size of the full grown plant, remember that they will be several feet wide at maturity. You will also need ventilation and maintenance space between a hedge and a building. You may be questioned why you are planting those cute little twelve-inch seedlings six or more feet from the house, but you will thank yourself later that you did.
Planting the New Hedge In the Ground
Before beginning to plant, put stakes at either end of the place where the hedge will be, and run a string between them to indicate the center line. Do not dig individual holes for the bushes unless they are the types that will grow very large and therefore must be widely spaced. For small, bare-root deciduous shrubs, open a long trench with one side directly beneath the string marking the center line. Make the trench wider and deeper than the size of the root systems, and loosen the soil in the bottom. The plants can be lined up single-file against the center-line side, or they can be placed in a staggered arrangement along both sides. They should be set the same depth as in the pot. If your hedge is to be used as a barrier, consider placing a hog wire fence inside it to prevent tunneling.
Whether you should prune at planting time depends upon whether your material is evergreen or deciduous. Evergreens from containers do not need pruning. Spring-set deciduous shrubs do, and fall-planted ones should be pruned early the following spring. This holds true even though the plants are several feet tall, because your goal is dense branching that begins near the ground. To produce such growth you must cut the bushes back to within six inches of the soil line. More pruning information here.
Feeding during future years should be done once or twice a year, especially just before the main spring growth. Water whenever rainfall is scant. Remember that these plants are growing in exceptionally crowded conditions and need all the encouragement you can give them.
There are available dozens of shrubs and trees that will make fine hedges. Check with your favorite nursery for appropriate varieties for your area.