By Susan Martin for Proven Winners
All images courtesy of Proven Winners
If your garden looks like it has seen better days by August, spruce it up with Summerific hibiscus which is kicking into high gear now. Whether you live in chilly zone 4 or steamy zone 9, these durable perennials will be the star of your late summer garden. See what it takes for them to thrive and how to choose the right variety for your space.
Summerific® perennial hibiscus, including ‘Holy Grail’ (pictured here), are in their prime in late summer.
This time of year, when other plants in your landscape might look like they’re ready to call it quits, Summerific® perennial hibiscus is kicking into high gear. Nicknamed “dinner plate hibiscus” for their impressive seven to nine inch diameter flowers, these plants bloom in shades of red, pink, lilac and white. Most have a scarlet eye that radiates out from the center of each ruffly textured blossom.
You might mistake Summerific perennial hibiscus for far less cold hardy tropical varieties, but they are actually very cold hardy, surviving winters as far north as zone 4. Their ability to withstand frigid temperatures doesn’t come with a trade-off. They also thrive heat and humidity up to zone 9.
Thick, overlapping petals help Summerific hibiscus flowers hold up in summer rains. Pictured is Summerific® ‘Cherry Choco Latte.
What Makes Summerific® Hibiscus Unique?
The diverse collection of Summerific hibiscus contains varieties with near-black foliage, leathery green leaves, a multitude of flower colors and patterns, and plants of different sizes and shapes. It’s impossible to pick a favorite!
Here’s what all Summerific hibiscus have in common, thanks to the skilled plant breeders who have worked for nearly two decades perfecting these amazing perennials:
Thick, overlapping flower petals which help the huge blooms hold up in summer rains.
Flowers that are produced at several nodes up the stems, resulting in coverage all over the plant, not just on the top.
A high bud count lengthens the season of bloom. In southern climates, it’s not unusual for the flower show to extend from late May to fall. In colder zones, they typically begin to bloom in mid- to late summer and last into the fall.
Leathery, interesting foliage that makes the plant attractive long before the flowers appear.
Plant breeder Hans Hansen kneels behind a hedge of Summerific® ‘Edge of Night’ perennial hibiscus.
Which Summerific® Hibiscus Should You Choose?
With Summerific hibiscus, it’s not a matter of choosing which one is the prettiest – they are all amazing! Instead, consider the amount of space you have to work with and the colors that will coordinate best with the other plants in your landscape.
Limited space? Choose the more upright oval-shaped “Crush” varieties of Summerific hibiscus if you need to go more vertical. Summerific ‘Lilac Crush’, for example, grows 5 to 5 ½’ tall and 4 to 4 ½’ wide. If you only have a few square feet to work with, try Summerific ‘All Eyes on Me’ which tops out at 3 ½’ tall and wide – about the same size as a clump of daisies.
Are most of the plants in your garden green? Add contrast with the near-black foliage and scarlet blossoms of Summerific ‘Holy Grail’ perennial hibiscus. If that feels like too much contrast, try Summerific ‘Evening Rose’ whose deep green foliage is more subtly shaded with purple pigments.
Perennial hibiscus like Summerific ‘Berry Awesome’ need plentiful sunshine to grow and bloom well. Aim for a minimum of six hours or more of direct sun with most of that coming in the afternoon. For reference, the plant in this photo is facing southwest.
What Conditions Do Summerific® Hibiscus Need to Flourish?
If you have the right conditions, perennial hibiscus is very easy to grow. The most important factors are plentiful sunshine and water. If you garden in dry shade or an arid climate, this is not the plant for you.
Bring on the sun! While perennial hibiscus can survive in part shade, you’ll find it grows and blooms far better in full sun. Direct UV exposure from the sun is needed to develop the dark foliage pigments, and you’ll see loads of blooms if plentiful sunshine provides the energy the plant needs to form the buds.
Consistent moisture in the soil and in the air is also important for perennial hibiscus to thrive. The large, fleshy roots soak up moisture readily and can penetrate through clay soil as long as it is moist. Choose a spot near your hose, downspout or sprinkler head when planting perennial hibiscus.
Perennial hibiscus emerges late in the spring but grow very quickly. When you see the buds start to look like ice cream cones, you’ll know the flowers are about to unfurl.
What Should You Watch Out for with Perennial Hibiscus?
If you’ve never grown this type of hibiscus before, a few unique traits might come as a surprise. Here’s what to watch for.
Late Arrival – Perennial hibiscus is one of the very last plants to re-emerge in the spring, sometimes as late as early June in the coldest climates. If the other plants in your garden have already sprouted but your hibiscus still looks dormant, give it a few weeks. All new growth will come from underground, so you can cut the dried stalks from last season down in the spring to make room for the new foliage.
Fast Growth – While many plants take several years to mature, you’ll be surprised how quickly your perennial hibiscus grows. Plan on it growing as much as an inch per day once it gets started. It’s best to plant it in a permanent spot with plenty of elbow room the first time rather than planning on moving it later when it outgrows its allotted space. For this reason, it’s also best not to leave it in a container for more than a few months.
Difference in Greenhouse Grown Plants – Because perennial hibiscus needs heat to sprout in the spring, it is often produced in a greenhouse before it lands on the retail bench. UV light inhibitors in the plastic or glass roofs of greenhouses don’t allow the deeper foliage pigments to develop properly. If the plant tag shows near-black foliage but it looks green, rest assured that the purple pigments will develop once you set the plant outside in the sun. Greenhouse grown plants also often have a lower bud count, but once planted outside, the bud count should increase as the plant matures in your garden.
Plant Pests – Sawfly larvae are often the first pests to attack perennial hibiscus in late spring, chewing holes in the leaves. They may be followed by Japanese beetles which chew on the blooms. Hand-picking and dropping the pests into soapy water will have the lowest environmental impact. For extensive infestations where the pests are threatening to skeletonize the whole plant, a stronger pesticide may be needed. Deer and rabbits may also dine on perennial hibiscus from time to time. Animal repellents like Plantskydd® and Liquid Fence® usually provide adequate protection.
Where Can I Buy Summerific Hibiscus?
You’ll find Summerific hibiscus available at garden centers across North America in zones 4-9. See a list of Proven Winners retailers. If you only shop for plants in the spring, you’re likely to miss these heat-loving perennials. They are typically stocked from summer to fall, so now is the time to head to your favorite local retailer. If you need to buy online and you live in the U.S., you’ll find them in the Proven Winners online store.
Contributor bio: Susan Martin is an avid zone 6 gardener and content creator who enjoys spreading her passion for plants to others across North America.
All articles are copyrighted and remain the property of the author.
By Laura Root
Photos courtesy of Jackson & Perkins
Gardeners are always thinking ahead to the next season or the next year. And, fall is the ideal time to think about spring. Flowering shrubs, perennials and spring bulbs are great choices.
Click here for an interesting article about spring bulbs.
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