There is a disease that gardeners get in spring. It’s called itchy fingers. When the new shoots and thick leafing out makes everything seem overgrown, itchy fingers want to prune it back. However, it’s important to know what you’re doing and what plants you’re doing it to.
Pruning is actually a very fine art and quite complicated. Each cut engenders a particular response from each tree or bush. Should it produce flower buds or vigorous new shoots? Will they grow straight up or sideways? How many will sprout and how will they affect the future shape?
A few simple bits of information:
- Do not prune spring flowering plants (such as rhododendrons, azaleas, lilacs) until after they flower. Then wait a week or two and prune as desired, before the new flower buds are set for next year.
- Late season bloomers (such as hydrangeas, rose of Sharon) can be pruned now, but leave enough good, fat buds for vigorous growth.
- Don’t severely prune needled evergreens until new little shoots have started – often May in New England. If they are very overgrown, don’t prune below green growth. Although many varieties will eventually put out new green shoots, it usually takes at least a year or more from bare wood. In the meantime, it will be awful bare.
- If you shear the messy shoots on crisp hedges and sculptured shrubs, you have to keep doing it to keep them neat. (But it’s most satisfying.) Keep the bottom of the bush wider than the top, so the bottom branches get light. A slightly triangular shape is best. Otherwise the plants bottoms get leafless, bare and see through.
- Most deciduous hedge plants (especially privet) can be cut way back and will sprout from the cut end. To renovate completely, cut back to 3 inches high. Even works on evergreen holly, rhododendron and leucothoe, but they take 2 years for any greenery to appear.
It’s important to understand that wherever you cut, you stimulate the plant. It puts out growth hormones. Depending on where, when and how you cut, determines which hormones. What’s more, each plant has its own preferences. And that is what causes the complexity and the art. Too bad they can’t talk and just say what they would prefer.
Ruth S. Foster is a landscape consultant and arborist. More gardening
information can be found on her website, www.mothersgarden.net.