Over the years, I’ve grown quite a few perennial flowers such as Hibiscus in my garden. They’re easily grown if you give them the conditions they want (in fact, they’re easily grown in most conditions)
This is a rather large family of plants ‘ about 220 species all told of annual and perennial herbs, shrubs, subshrubs and trees.
While you won’t grow too many Hibiscus trees in zone 4, you will likely grow all the other forms. Hibiscus are a member of the malvaceae or Mallow family which lends them a common flower habit with some of our less popular roadside weeds (white mallow) and our more popular garden plants (Lavatera).
- Sunshine: Sun to part shade
- Soils: just about anything other than drought and heavy clay
- Propagation: Seeds or Tip Cuttings
- Height: From 24″ to 60″
- Flowering Time: late summer through fall
- Hardiness: USDA 4 for common perennials
Common Garden Center Plant: Hibiscus moscheutos
Hibiscus moscheutos is the plant that garden centers sell as perennial hibiscus. Native to the Carolina forests, most perennial Hibiscus are rated a USDA zone 4 for winter hardiness and down to a warm zone 9 for summer heat tolerance.
They are typically July-August bloomers although a few bloom later than this. If grown in good rich soil, this plant will quickly turn into a four to six foot tall bush every spring (dying to the ground over winter). The flowers will also be amazingly large at six inches across.
I have grown this plant in sand and clay and have abused it terribly, it survives almost every kind of soil although it doesn’t bloom well when drought strikes.
The only problem I ever had was winter-hardiness on some of the dwarf varieties but that might have been my gardening rather than the plant. Given that I like the taller varieties better anyway, it was no loss.
They are usually pruned to the ground in the fall and regrow (starting as one of the last perennials to emerge) each spring.
The most commonly available form of perennial Hibiscus is ‘SouthernmBelle’ because it is carried by most seed catalogues.
This wonderful plant, if grown in a moist, rich soil in full sun or part shade can easily hit 4 to 6 feet tall in a season and be covered by a delightful display of huge six inch blooms in late summer.
The breeders have done their magic giving us plants such as ‘Cotton Candy’ pink and white, ‘Satan’ blood red, ‘Radiation’ deep pink, and ‘Crimson Wonder’ with you guessed it ‘ crimson flowers.
‘Kopper King’has coppery-red foliage with massive white flowers containing a red eye; this is an excellent show-stopping fall bloomer. I’ve also grown ‘Lord Baltimore’ which is a rather large bushy perennial Hibiscus plant with massive bright red flowers and this has received more than its share of garden envy while in bloom.
‘Fantasia’ is a compact form, only growing to three feet tall but it does have massive rose-pink flowers.
If you purchase perennial Hibiscus moscheutos, be extremely careful with transplanting. It resents having its roots moved and can turn from a healthy hulk into a basket case with careless moving or even weeding that disturbs its roots.
Propagating Perennial Hibiscus