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.