Hardy Perennial Hibiscus
October 10th, 2007
The flower form of hibiscus is very common to the tropics, blooms typically 4-6 inches across that are brightly colored and form on shrubs. Many people in more northernly climes also grow them as patio plants.
But did you know you could plant hibiscus plants with flowers twice the size in the ground in your garden and they’d be hardy? You can.
The plant you’re after is Hibiscus moscheutos sold as Rose Mallow, Swamp Mallow, Hardy Hibiscus, or Perennial Hibiscus. This large perrennial can be hardy as far north as zone 4, and will produce absolutely huge 10-12 inch blooms in shades of white, red, and plum.
The draw of this plant doesn’t stop there though, a quasi-recent new variety called Kopper King features burgundy & green foliage with deep cut leaf margins, making it an excellent plant even when not in bloom.
Even nicer, the newest Pinot varieties (Pinot Noir having red blossoms, Pinot Grigio having white blossoms), have mottled purple and green foliage with a very interesting crinkled texture.
These plants require full sun and a good deal of water. They’re late starters, often not emerging until late May where I live, but they grow rapidly to 3 feet. The best solution for zone 4 or 5 gardeners is it cut them back after the first killing frost in Fall and then cover them when cold weather hits with a styrofoam rose cone thing. That should give them just the little bit of protection they need in order to survive and or start a little earlier than late May.
I’ve not noticed any disease problems with mine, with plenty of water they do just fine. However Japanese beetles do like their foliage so be vigilant and either put out traps or manually kill the little buggers in the evenings where they are out and about.
All told, this plant is one of my favorite plants. It is relatively carefree, gives you striking foliage, and striking blossoms. Plus, it is somewhat unusual from your standard suburban garden fare.
October 13th, 2007 at 10:27 am
You know, I’ve wondered about this. Regular hibiscus won’t make it through the winter even in my zone 9 neck of the woods. But I have noticed neighbors who have huge hedges of hibiscus that don’t seem to be effected. How do they take the heat? I’ll have to try them next season. Thanks!
October 20th, 2011 at 12:00 pm
My hibiscus wintered very well in the ground and grew to be about 2 feet tall but never flowered. Is this normal for the first planting? I was planning to cut it back after the frost to see if next year the blooms appear.