Flowering shrubs can be a useful and beautiful addition to home landscaping. Many of them are inexpensive and fast-growing, and thus make good hedges or screening plants.
Whatever their function in your yard, most shrubs will benefit from an annual pruning job.
As a general rule, shrubs that bloom on last year's wood should be pruned just after flowering. These include lilac, forsythia, honeysuckle, mock orange, and deutzia. Shrubs that bloom in late spring or summer usually form flowers on new growth and should not be pruned until late winter or early spring. Hibiscus, spiraea, and privet are in the latter group.
Big, old, leggy bushes or too-tall lilacs may need renewing. To do this, cut out one-third of the branches right back to the ground. Fat new shoots will come up from the roots. Then these can be pruned to induce side-branching. Next year, cut out another third of the old branches; and the year after that take out the last of them. Then you'll have a brand-new shrub.
Younger shrubs need trimming to shape them and encourage growth in the right direction. If you were to look at a twig before it leafed out, you would see at the tip a bud or pair of buds. These are called terminal buds and are often larger than the others.
New growth develops from terminal buds to make the branches grow longer.
Buds occurring along the side of the branches are called lateral buds and usually just produce leaves, but if the terminal bud is cut off, the lateral bud just below the cut sends out a shoot.
Remember when you prune, new growth will begin on the first bud below that cut.
You can determine the shape of a shrub by trimming to a bud that points in the direction you want the plant to grow. If a shrub looks droopy and you want the branches to grow up or inward, trim to a bud on the inside of the branch. On the other hand, if you want spreading branches and an uncrowded center--in a magnolia, for example - prune to an outside bud.
Avoid a boxy or round-ball look by varying branch lengths as you trim.
Some shrubs, such as lilacs, sucker badly. Remove suckers by cutting them off at ground level. Persistent ones may need to be dug back to where they are coming off the roots and cut out there.
Evergreens, such as yews, junipers, and arborvitae, should be clipped before their new shoots are three inches long. Usually, they will develop two new growing points for each cut. If you want taller growth, prune the side branches. For more bushy growth, cut the top shoots.
Do not try to renew evergreens, because if you cut them back past the last green needles you'll be left with bare, stubby branches and a few feeble shoots.