Pruning to shape:
In shaping, your artistic side plays a role in determining what form a particular plant should take. Every plant has a natural shape; its growth tends to conform to a natural pattern, whether round, gumdrop shaped, wide spreading, vase-shaped, or arching. Observe what a plant’s natural shape is, and then prune the plant in a manner that will allow the natural form to continue to develop. Remove any excess growth that obscures the basic pattern or any errant growth that departs from the natural form. Use thinning cuts.
When pruning to shape, make your cuts above a bud or side branch that points in the direction you’d like the new growth to take. If you have no preference, remember that generally it is better for a new branch to grow toward an open space than toward another branch. Also, it is generally better for growth to be directed toward the outside of the plant than too ward its interior. Try to eliminate branches that cross and touch one another. Crossing branches may rub together, suffering injury, and are usually unattractive, especially in deciduous plants out of leaf.
Pruning for flower production:
Flowering shrubs bloom either from new growth or from old wood, depending on the plant species. Before you prune, determine which sort of growth bears flowers. In this way you can avoid inadvertently cutting out stems that would give you a flower display.
Most spring flowering shrubs bloom from wood formed during the previous year. Wait until these plants have finished flowering before pruning them (or do some pruning by cutting flowers while they are in bud or bloom). Growth that the shrubs make after flowering will provide blooms for the next year.
Most summer flowering shrubs bloom on growth from the spring of the same year. These are the shrubs you can prune during the winter dormant season without sacrificing the next crop of blooms.
A few shrubs bloom twice or throughout the growing season (many roses, for example). Spring flowers grow from old wood; later blooms come both from recent growth and from wood of previous years. During the dormant season, remove weak and unproductive stems and if necessary, lightly head back remaining growth. During the growing season, prune as necessary to shape while you remove spent blossoms.
These evergreens fall into two broad classes; those with branches radiating out from the trunk in whorls and those that sprout branches in a random fashion. Spruce, fir, and most pines are examples of the whorl type; arborvitae, hemlock, juniper, and Taxus (yew) are examples of random branching conifers. Pruning guidelines differ for the two groups.
On whorl branching types, buds appear at the tips of new growth, along the lengthening new growth, and at the bases of new growth. You can cut back the new growth “candles” about halfway to induce more branching, or you can cut them out entirely to force branching from buds at their bases. The point to remember is that you must make cuts above potential growth buds or back to existing branches. Cutting back into an old stem- won’t force branching unless you’re cutting back to latent buds.
The random branching conifers can be pruned selectively, headed back, even sheared; new growth will emerge from stems or branches below the cuts. But when you shorten a branch, don’t cut into bare wood below green growth; most kinds (yew is an exception) won’t develop new growth from bare wood.
Controlling Height: Some conifers-chiefly the random branching kinds, plus deodar cedar and hemlock can be kept at a controlled size, either as dense specimens or as hedges. When growth reaches within a foot or so of the size you desire, cut back all but about 1 inch of the new growth. This will produce enough small side branchlets to make full, dense foliage. Once this bushy growth forms at he ends of the branches, you can hold the plant to a small size year after year by shortening new growth that develops and cutting out any wild shoots.
Repairing damaged trees: When a conifer has been damaged by cold or breakage, you may have to remove entire limbs. It’s almost impossible to restore the natural shape, but you can often make the most of the situation by trimming or training the damaged plant into an unusual sculptural form. If the central leader has been damaged, you can stake one of the next lower branches vertically and train it as a new leader.
Pruning Deciduous Fruit Trees:
The rule of Thumb is Deciduous fruit trees should be pruned during winter while the trees are dormant and after the leaves have fallen to the ground but before new buds have swelled. Each type of fruit tree needs to be pruned differently, so it is important to know which kind of tree you’re pruning and how to prune it properly.
For example, apples bear their fruit on spurs that bear again and again, sometimes for as long as twenty years. If you whack off all the spurs you’ll have no fruit. In general apple trees need very little pruning once a main framework of branches has been established. It’s important, however, to cut off all the leaves even from low-chill varieties, such as ‘Anna’, that may not lose all their foliage in winter. Leaving old leaves hanging on while new ones form can lead to apple scab, a fungal disease that causes black blotches on leaves and then, subsequently, causes the fruit to rot. Apple scab is at its worst during rainy years. Dormant spray helps prevent apple scab.
Plums also bear on spurs. The pruning of mature European plums is minimal, as for apples, but Japanese plums grow so vigorously that they need heavy pruning of new growth.
Apricots bear partly on one-year-old wood and partly on spurs that continue to bear well for four or five years. The older branches must be headed back so that one-fifth of the bearing wood will be replaced. Peaches and nectarines need the heaviest pruning of all: their fruit is borne on one-year-old wood. By pruning them hard, you encourage new growth to replenish fruiting wood. Figs need very little pruning at all except to control tree size and the density of foliage.
Always follow pruning with a Dormant spray to prevent insects such as mites and scale from overwintering and infesting plants. A Dormant spray such as Volck Oil, lime sulfur, or fixed copper should be applied to Roses, Deciduous fruit or ornamental trees every winter after their leaves have dropped to prevent buildup of disease. If any leaves are still clinging to the plant in January, they should be clipped off prior to spraying.
How to Prune a Rose; The Basic Principles:
(Excerpted from “Southern California Gardening, A Month-by-Month Guide” by Pat Welch ©2000)
If you moved to Southern California from a cold winter climate, forget what you may have learned there about rose pruning. In the East and Midwest roses are pruned hard in fall –down to 12 or 18 inch stubs-so they’ll survive the winter. Here we should never shorten a healthy, productive cane. The more good wood left on the plant, the earlier it flowers and the longer it lives-so don’t cut your plants way down. Try never to cut lower than your knee. Many of our roses can be left 4 ft. tall after pruning but the canes that remain should be thick and healthy ones. Cut closely above a promising outside bud, so new growth will point outward. Cut ¼ inch above the bud, even closer if you can do so safely. Make your cut straight, not slanted. A sharp angle can dry out wood and kill the bud. Remove the suckers, which are canes that spring from below the bud union. Instead of growing from the bud union like the canes of the variety you want, they grow from the rootstock. Suckers are usually easy to recognize because they’re thinner and pricklier that the canes that arise from the bud union and their leaves are usually smaller and shaped differently from the other leaves on the plant. If allowed to persist they’ll sap strength from your varietal rose. Suckers are easiest to reach after the major pruning is complete. The best way to get rid of one is to grasp it firmly with a gloved hand, work it back and forth and around and around to loosen it, then pull it off with a mighty yank. If you can manage this you’ll get the bud cells along with the stalk, but if instead you cut it off two or three more suckers are likely to spring from the same spot.