Gardening with Gary

Gardening Advice from an Expert

Rose of Sharon

Linda writes~ I would like information on the Rose of Sharon. When to plant, does it tolerate shade, is it a perennial in zone 4, when and how to trim.

A. Rose of Sharon, Hibiscus syriacus, is not a rose, but its large blossoms attract hummingbirds and tiny insects that hummers also eat. The flowers on this woody shrub come in several colors, including white, pink, purple and red. Its leaves do not come out until late in spring, causing false alarms in gardeners who think their plants may have died. Be patient.

It is a perennial woody shrub, blooms late summer to early fall, needs moist but well-drained soil with compost. Give it partial sun or light shade, not full shade though, nor too hot in the summer. Watch its watering carefully especially when blooming or producing new vegetative growth and in periods of low precipitation.

Do not prune until flowering has ceased, so as not to disrupt its natural habit and production. By pruning every fall, you will encourage better growth and more flowers in the following season. Unpruned shrubs tend to get lanky and bloom only sporadically. Shape carefully, not too much at one time. Remove any lower suckers and all weak, spindly stems.

Rose of Sharon has no specific feeding requirements. Feed monthly or biweekly with a standard garden fertilizer as directed. Lack of food will lead to weak growth, less flowers, and greater chance of insect attack. Thrips are its more common invader.

Hardy in Zones 5-9, but will tolerate your Zone 4 if protected well in the winter with thick mulch and is grown near a building for soil heat. Protect from drying cold winter winds and snow drifts.

Best planted in the early spring after all danger of frost has past, or in the early fall before temperatures get too cool. Water well but do not feed, as the new tender growth in late fall will be killed by cold snaps.