Rose of Sharon

(Question)

We have had some extensive landscaping done and had to raise up the rose of Sharon. It is now only producing leaves on the lower part of the tree. Should I trim off the branches that are not producing leaves? Start with a smaller bush/tree?

(Answer)

Thank you for contacting the Toronto Master Gardeners about your Rose of Sharon (Hibiscus syriacus). I can’t tell from your picture whether the new growth is on existing lower branches or whether it is coming from the root. There are several factors that could be contributing to what you are seeing with your plant :

  • Rose of Sharon is a late starter, one of the last shrubs to leaf out in the spring, and some branches will leaf out before others. We have had a long cold spring, so it could be that your Rose of Sharon is particularly late to leaf out this year.
  • It could be that some of your branches have succumbed to winter kill.
  • Transplanting a Rose of Sharon should be done in the spring (when was yours moved ?), and it takes a while to get established. If the growing conditions (soil, hours of sunlight, watering) have changed as a result of your landscaping work, this adjustment could take longer.
  • Often a Rose of Sharon will lose its upper growth but regrow from the root.

The good news is that you are seeing new growth. Since there could be a combination of things happening with your shrub, I would be inclined to wait for a bit and see how it  grows in the coming weeks. I suggest that you do a couple of things for now:

  • Scratch the bark on some of the upper branches of your shrub. If it is green underneath the bark, the branches are alive and well.
  • Rose of Sharon prefers organically rich, moist soil, so you could consider adding compost or organic mulch to the surface of your soil, depending on what you might have already done with the soil as part of your landscaping work.

After a few weeks, if the upper branches have not leafed out, they probably aren’t going to, and if they are truly dead (no green under the bark) then you could go ahead and prune them out (cut back to the trunk or the live branch they are growing from). If new growth has continued either on the lower branches or from the root, then I see no need to replace your shrub.

07/07/2022