The hardy hibiscus is a slow grower, but it builds size and energy through the summer to finally start flowering in late summer and continue until frost. It puts on quite a show. The flowers are colorful and can be 10 to 12 inches in diameter. They are sometimes called the dinner plate hibiscus for that reason.
Sun Requirements: Full sun
Bloom Period and Seasonal Color: Late summer to fall in colors such as white, pink, red, and bi colors.
Mature Height x Spread: 2 to 5 feet x 2 to 5 feet
Added Benefits: attracts beneficials, attracts hummingbirds
Yes, you can grow hardy hibiscus in New England. Often people think of the tropical houseplant, but there is a hardy version that looks just as beautiful. The hardy hibiscus is a slow grower, but it builds size and energy through the summer to finally start flowering in late summer and continue until frost. It puts on quite a show. The flowers are colorful and can be 10 to 12 inches in diameter. The plant can grow 5 feet tall and wide filling in an area in the perennial garden. The flowers only last one or two days, but they come in succession keeping the flower show going.
Where, When and How to Plant
Grow hardy hibiscus throughout our region. Plant after all danger of frost has passed and throughout the summer in well-drained, fertile soil. Hardy hibiscus like the heat and full sun, so consider planting them near a south-facing wall or building. Space plants 2 to 3 feet apart in the garden.
Hardy hibiscus like moist soils, so keep plants well watered and mulched with bark mulch to prevent weeds from crowding them and maintain the soil moisture. Fertilize in spring with a layer of compost.
Regional Advice and Care
Hardy hibiscus is slow to emerge in spring in cold areas so be patient. They may not pop out of the ground until June. Pinch the shoots of young plants in early summer to encourage branching and more flower stalks to form. Hardy hibiscus can also self-sow and become weedy. The self-sown seedlings will not necessarily be the same color as the parents, but can be transplanted and moved throughout the garden if so desired. Keep plants deadheaded to look tidy and prevent the seeds from sowing if you don’t want seedlings. Cut back plants after a frost to the ground and compost the flower stalks.