HG: Homegrown Column November 29, 2008
I have a Rose of Sharon bush that has grown so tall it blocks my view from my window. I have my shrubbery trimmed by a company in town every spring and they never trim the Rose of Sharon bushes. Is there a reason? Can I trim it myself and when is the best time?
Thanks for your help
I think the reason your yard care people aren’t pruning it is because most people let their Rose of Sharon just grow.
Left to themselves, they will form an attractive rounded to upright vase-shaped shrub that will get 8 to 15 feet tall. The size and shape is determined a bit by the variety and where it’s growing.
I have some 22-year-old plants in my yard that are a good 15 or 16 feet tall. They are a variety called “Ardens” that has small double lavender pink flowers and tends to grow in that upright vase shape.
They’re also crowded into a full shrub bed so they’re probably a bit taller than one planted out on its own since they can’t grow wide.
Other varieties, especially the single flowered varieties such as “Aphrodite” and “Minerva,” tend to grow in a more rounded shape, not getting quite as tall but spreading wider.
Now, as to your question about pruning Rose of Sharon: since they bloom on current season’s growth, you can cut them back pretty hard every year to keep them shorter. The time to do it is early in the spring, about the month of March. I’d cut them back to 2 or 3 feet off the ground.
Going farther than that could be a bit risky. Consider removing or reducing the oldest, thickest
stems in favor of younger, more vigorous ones. Cutting the plants back this far should result in a plant that is 4 to 5 feet tall by the end of the season.
You also will want to selectively prune back individual shoots so you end up with an oval or rounded shape. By doing this you can modify the growth habit of the plant and make an upright growing variety more rounded or vice a versa. This also results in a more natural looking plant.
You’ll probably need to have this done every spring to keep the plant from covering up the window.
I have just planted an ajuga in a sunny spot where I want it to spread and cover the ground. I hope it winters over. My question is, will it spread with cedar mulch over the ground?
I have good news and bad news.
The good news is that ajuga is a great ground cover here. It has striking bronzy green leaves — some varieties have silvery, copper, purple or even pink in them — with showy violet purple flowers in early spring.
It’s reliably winter hardy, though it does like regular moisture.
The bad news is that around here ajuga almost always needs to be planted in the shade. Our bright intense sun, low humidity and high temperatures will pretty much fry any ajuga in an unprotected area.
I’d start looking around your yard for a spot that gets pretty good shade. Even a spot that’s sunny in the morning and shady in the afternoon would be an improvement.
Other ground covers that could take the sun include sedums, hardy iceplants, creeping potentilla, thyme, some of the perennial geraniums, hen and chicks and creeping phlox.
As to your original question, the ground cover should grow fine over the mulch as long as it is not too deep. I’d try to keep it 2 inches deep or less.