Althea, also commonly known as Rose of Sharon, offers colorful flowers on a slow growing, low-maintenance shrub. Pruning althea is not essential, but it can approve the shrub’s form, control its size and and promote larger flowers. For herbaceous peonies, however, pruning is essential to prevent the spread of diseases that attack the plant. Tree peonies can also benefit from pruning once they are well established. The key to pruning altheas and peonies is to do it properly. Improper pruning can do more harm than good.
Things You’ll Need
- Pruning shears
- Lopping shears
- Pruning saw
- Prune dead or damaged limbs at any time during the year. Cut back to the point of origin.
- Prune lateral branches, or those that originate from the main trunk to improve shape or control growth. Where branches cross over one another, remove one of the branches. Prune in late winter in southern regions and early spring in northern regions.
- Cut back previous year’s growth in the spring to two or three buds per branch to produce larger flowers, if desired. An althea that is not cut back will produce more, but smaller, blooms.
- Cut herbaceous peonies to the ground in the fall.
- Prune damaged or dead limbs from tree peonies after leaves put out in spring.
- Prune interior branches after several years of growth to improve air circulation.
- Cut away shoots that grow up from the root stock as soon as they appear.
Tips & Warnings
Always sterilize pruning tools with nine parts water mixed with one part bleach after each use to prevent transferring diseases from one plant to another.
Never cut tree peonies all the way to the ground.