Eye-catching hibiscus blooms are happening now at the Arboretum in the North Terrace and Oasis Gardens, including hardy hybrid hibiscus varieties (such as Hibiscus “Midnight Marvel” and Hibiscus “Berry Awesome” SUMMERIFIC®) and rose-of-Sharon (such as Hibiscus syriacus “Notwoodtwo” White Chiffon™). These are great floriferous specimens if you are looking to transform a space into a vibrant tropical oasis while extending the summer feel in your garden into the early autumn months. There are three different classifications of hibiscus (hardy, shrub, and tropical) and they are all perennial in their native habitats. Most hibiscuses can be traced back to Hibiscus moscheutos which is a species native to North America.
Hardy hibiscuses are erect, woody-based perennials that typically grow 4 to 8 feet tall. These hybrid species are winter hardy (typically to USDA zone 4 or 5) and produce spectacular blooms from mid-summer to early fall. Their large, disc-shaped flowers can reach upwards of 10 inches in diameter and feature five flat, showy, overlapping petals in a variety of bold colors. Some highlights from the Arboretum’s collection include Hibiscus “Midnight Marvel” which features carmine-red blooms and Hibiscus “Summer Storm” SUMMERIFIC® that has deep purple foliage and produces pink-blushed flowers with dark rose stripes and a deep red central eye. Most species also feature a pale-yellow, tubular staminal column in the center of each bloom.
Though individual flowers typically remain in bloom for only one to three days, each plant typically produces up to 250 flowers that bloom in succession every growing season. These hardy perennials will die back in late fall and new foliage will typically emerge in late spring. Pruning is encouraged after a hard frost leaving about six inches of the stems exposed, so you don’t lose track of your plantings!
Hibiscus syriacus or rose-of-Sharon (also known as shrub hibiscus), is a vase-shaped, multi-stemmed deciduous shrub native to China that reaches heights of 8 to 15 feet tall. This species of hibiscus has a woody habit and blooms on the same structure every year. Hibiscus syriacus “Notwoodtwo” White Chiffon™ is featured in the Arboretum’s North Terrace gardens and presents semi-double, pure white flowers with a prominent center staminal column. This cultivar will flower continuously from mid-summer to fall.
Hibiscus × rosa-sinensis, commonly referred to as tropical hibiscus or Chinese hibiscus, is a hybrid from southeast Asia and is technically a shrub like H. syriacus, but it is much less cold-hardy (USDA zones 9-11). These varieties are best utilized as seasonal summer plants or as house plants since they are not frost-tolerant. You can currently view a few seasonal varieties on summer display in the Arboretum, including Hibiscus × rosa-sinensis “Double Peach.”
Be sure to visit the Oasis and North Terrace gardens and immerse yourself in a tropical oasis this summer! You can find exact locations and photos of the different hibiscus species in the Arboretum’s collection using our Arboretum Explorer Plant Finder Tool!