I have a four or five year old pink rose of sharon with single blooms. The blooms open serially one by one from the base of each branch up to the tip. I’ve seen a few bushes around like this but most seem to have lots of blooms at the same time including at the tips of branches.
I’ve read online that young bushes tend to grow straight rather than bush out and wonder if there is hope mine may change in time. However, to minimize shade on the garden next to the bush I have tied the lower branches close in to the trunk and allowed it to spread only higher up. I wonder if this might be the problem.
I’m in a narrow Victorian house in downtown Toronto with soil that is neither sand nor clay and not particularly wet or dry.
I have photos of the bush on my phone but don’t know how to save them or send them I’m afraid.
It would appear from your email and our subsequent discussion that your Rose of Sharon is very healthy. It seems to have enough sun and you even mentioned that you had taken steps to minimize shade by tying the lower branches close to the trunk to allow it to spread. You also wondered whether this might be the reason why your Rose of Sharon has many more blooms lower down. It is possible that some careful pruning might enhance the blooms higher up the plant. You mentioned that your bush is quite young. Young Rose of Sharon shrubs tend to grow upward and have an erect form and respond well to light thinning and shaping. I’ve attached a website that gives tips on pruning. You also mentioned that it has a large quantity of seeds. I’m attaching a link to a website on harvesting and growing Rose of Sharon seeds. I’m also attaching a response from our Master Gardener file that gives information on growing this beautiful plant. Good luck!
Rose of Sharon prefers full sun, soil that is rich and moist, and is hardy to USDA zone 5 (i.e. Canadian zone 6). Since it is borderline hardy in Toronto, it is best to give it a sheltered location to protect from winter kill. Giving it a good 2-3 inch layer of organic mulch around the root zone in the Fall will also help. In late Spring, after it has leafed out, prune out the winter damaged branches and apply a balanced 10-10-10 fertilizer to give it a head start. A mid-summer application of a low nitrogen 0-10-10 fertilizer will promote root health and flower production. Do not apply fertilizer after August as this will encourage tender new growth that will not overwinter. Water deeply but not too frequently, and take care not to let in sit in wet soil or the roots will drown. Amend the soil regularly to keep it humus rich and healthy.
https://www.gardeningknowhow.com/ornamental/shrubs/rose-of-sharon/pruning-rose-of-sharon.htm
Rose of Sharon Seed Propagation: Harvestion and Growing Rose of Sharon Seeds