Plant pruning tips

Q. When and how do I prune my azaleas and rhododendrons?

Donna from Youngstown

A. Some gardeners use green leaves of rhododendron and azaleas in holiday wreaths.

Others use magnolia leaves if they are lucky enough to have a sweet bay magnolia (M. virginiana) or if they have a friend in southern Ohio who has a true southern magnolia (M. grandiflora).

Whatever the greenery you choose, pruning at this time of year is fine on these species.

But, gardeners should focus on what they are cutting. They should focus on what they are leaving behind for the spring blooming season.

Azaleas and rhododendrons are members of the same family, and all azaleas are in fact rhododendrons. They are both in the genus Rhododendron.

The rounded buds on the ends of branches are the blooms for our spring flowers. They are formed in July each year. Be aware and cut foliage from other areas of the plant or at least limit what is pruned so the flowers can be enjoyed in spring.

Overall, these plants should not need much pruning. We recommend pruning these plants a few weeks after the bloom is completed.

For the entire plant, wait until new shoots have emerged on the plant to see what the new shape for the season might be. Cut back older shoots to make room for these new ones.

A general recommendation is to snap off faded flowers on rhododendrons, but not on azaleas in late spring. This will sometimes lead to better flowering on rhododendrons.

When it comes to reducing the size of these large shrubs, we suggest using a light pruning while the new growth catches up by filling in the bare spots of the plant. This is called thinning.

A gardener can simply remove a branch here and there (starting with dead, damaged or crossing branches) each year to improve air circulation and room for new shoots.

When these shrubs become completely overgrown, a heavy pruning may be in order. This will rejuvenate the plants.

Azaleas can be pruned to 12 inches from the ground. A healthy plant will respond with an abundance of new shoots.

Many gardeners are fearful of doing this, as it has an immediate effect on the appearance of their landscape.

Rhododendrons can be unsightly when they are heavily pruned, but this can bring the plant down to size and improve flowering.

For detailed information on pruning and caring for these wonderful shrubs, go to: go.osu.edu/azaleasrhods.

Eric Barrett is OSU Extension Educator for agriculture and natural resources in Mahoning County. Call the office hotline at 330-533-5538 from 9 a.m. to noon Mondays and Thursdays to submit your questions.