By mid-fall, most plants have stopped flowering. However, if you’d like an autumn bloomer, fall is the perfect time to plant hardy hibiscus, such as the beautiful Rose of Sharon. Discover varieties of hibiscus flowers and planting tips from The Old Farmer’s Almanac.
Rose of Sharon
Rose of Sharon (Hibiscus syriacus) is one of my favorite late summer shrubs. Hardy hibiscus is so tough the plant will come back year after year as far north as zone 5. In the same family (Malva) as hollyhocks, mallows, and okra, this hibiscus can have single, double, or semi-double blossoms in a wide range of colors including true blue—a rare color in the flower world. If you need a shot of blue to contrast with all the autumn yellows and golds, look for ‘Blue Bird’, ‘Azurri Blue Satin’, or ‘Blue Chiffon’.
Forming a multi-stemmed shrub that can grow to be 8 to 12 feet tall and 6 to 10 feet wide, they can be planted 10 to 12 feet apart to make a colorful hedge. If you prefer a standard tree-shape, the extra stems can be carefully pruned out to give it that appearance. Since they flower on new wood do any pruning early in the season to give the plant a chance to recover and regrow new branches. They require full sun to produce the most blossoms but will still bloom in light shade. They prefer moist, well-drained soil and love hot summers. Fertilize in the spring with some compost and mulch around the base to keep the soil moist.
To encourage bigger blossoms, you can pinch off the extra buds, leaving only 2 to 3 per branch but I’d go for quantity over size any day.
Luckily this is one plant that is not attractive to deer but the migrating butterflies and hummingbirds love it!
Note: Rose of Sharon is considered an invasive in some parts of the country. To avoid the excessive seedlings that cause this problem, look for a sterile cultivar that doesn’t produce any seeds.
If you want to grow some really huge blossoms look for Hibiscus moscheutos. Most of them have blooms that are easily 10 inches across. Talk about dinner-plate size! Though these giant satiny flowers look tropical, the plants are hardy to zone 4. Unlike Rose of Sharon, they die back to the ground each year but make an amazing amount of growth over the summer, eventually reaching 3 to 4 feet tall. They can be slow to emerge in the spring so be patient.
We grew a variety called ‘Southern Belle’ from seed but there are many other hardy hibiscus to choose from. If you want to attract hummingbirds try ‘Cranberry Crush’ or ‘Midnight Marvel’. Both have irresistible red flowers.
The flowers only last for a day or two but there are many buds coming along to prolong the show.
Some varieties have the added feature of red, maroon, or copper-colored leaves to add to the drama.
I just planted one called ‘Cherry Brandy’ that has green leaves with a red blush.
Planting Hearty Hibiscus
If you’re planting in the fall, here’s how to plant a container-grown plant bought at a nursery:
- Dig the hole in your garden twice size of root ball of plant.
- Mix the soil you dug out of the hole with mulch or compost.
- Take the plant carefully from container, keeping a hand on the bottom of the plant.
- Lower the plant gently into the hole, centering carefully.
- Backfill the hole with your soil/mulch mixture.
- In the fall, we don’t usually add fertilizer as we don’t want to encourage the plant to grow.
- Build a little well around the plant for the water.
- Tap the soil around the plant gently.
- Water in your plant with a nice drink.
- The plant will rest quietly all winter, awake in spring, and flower by mid-summer!
If you would like to add an exotic touch to your late summer garden look no further than the hardy hibiscus.
More Tropical Flowers
Love the look of tropical flowers? Another colorful tropical plant is canna. A tropical bulb canna is hardy in zones 7 to 11, cannas boast super-sized leaves and showy stalks of yellow, red, salmon, orange, pink, or bi-colored flowers that bloom in mid to late summer. Easy to grow, canna also attracts butterflies and hummingbirds! See the Almanac’s Canna Growing Guide.