Did you know perennial hibiscus are a North American native plant and they are hardy here in Minnesota. The first time I realized we could grow a plant with flowers the size of dinner plates, I was flabbergasted. From the giant flowers to the glossy foliage, everything about a hibiscus feels tropical. In fact, there are tropical hibiscus that are not winter hardy outside. So, make sure to pay attention to the labels. Perennial hibiscus are in the Hibiscus moscheutos family and tropical hibiscus are Hibiscus rosa-sinensis. While tropical hibiscus are great as a patio plant, they are not hardy in zone 4.
When I first started working here, we grew them in a #1 pot, and we only grew around 5 different varieties. Most of them had red flowers and I think they may have all had green foliage. Now we grow them in a much larger pot, and I think we grow more than 10 cultivars. Throughout the years, they have been breeding for longer flowering periods by selecting plants that bloom from the top to the bottom of the plant rather than just at the tips. Newer cultivars form beautiful mounds of foliage that ranges from bright green to black and can be completely covered with flowers. If you are looking for the longest blooming hibiscus, look for words such as indeterminate and free flowering in the descriptions.
While Hibiscus with red flowers like ‘Cranberry Crush’ are still very popular, my favorites have multicolored flowers and deep dark foliage such as ‘Cherry Choco Latte’ and ‘Starry Starry Night’. While all hibiscus prefer full sun, the dark leaved varieties really need the UV light for the foliage color to develop.
Hibiscus are heat and day length dependent so don’t worry if your hibiscus doesn’t emerge right away in the spring. Usually they won’t start breaking dormancy in this area until June. But when they do, it doesn’t take long for them to reach their mature size. Hibiscus range in size from 3’ – 5 ½’ tall so choose a spot with room for them to grow! They need full sun and consistent moisture. Growing big blooms takes a lot of energy!