This column is being reproduced with the permission of Steve Smith, The Whistling Gardener, and owner of Sunnyside Nursery in Marysville.
Exactly one year ago I wrote about the virtues of plants in the hibiscus family.
Specifically I wrote about the perennial hibiscus that is native to our eastern United States, the shrub hibiscus known as the Rose of Sharon which is an Asian introduction, and to a lesser degree the tropical hibiscus that many of us associate with Hawaii or at least the more southern portions of our country.
Due to the National Gardening Bureau declaring 2021 the Year of the Hardy Hibiscus, I find myself back once again visiting these reliable and late blooming perennial and shrubby plants. For color well into the end of summer, they are hard to beat.
Let’s start with the perennial form first…
Hibiscus moscheutos, sometimes called “Swamp Hibiscus,” grows in the wet portions of the southeastern US and breaks dormancy late in the spring, growing up to eight feet tall with very large hibiscus-type flowers in August through September.
From this species, breeders have developed new introductions (that have vastly improved the garden-worthiness of this native) that are now more compact and well-branched, growing only three to four feet tall with the same (if not larger) flowers and even colorful foliage in the dark burgundy ranges.
If you are after for that tropical look in the garden from a completely hardy perennial, then look no further than hardy hibiscus. Just keep in mind that these showstoppers come up late in the spring (sometimes as late as June) and don’t strut their stuff until August and September.
As for purchasing them at a garden center, you won’t even see them until July, so if you are primarily an April and May shopper you may have never encountered them. Now is the time to view and purchase them while they are in full selection and possibly even blooming.
Easy to grow, all they need is the absolutely hottest place in your garden and consistently moist soil. It’s that easy. Here are some varieties to look for…
Pink Passion: Sports dark purple foliage with six to seven-inch reddish-pink flowers.
Pink Candy: Same as above only with “cotton candy” pink flowers.
Dark Mystery: Dark wine purple foliage with eight to nine-inch white flowers that have a cherry red eye and dark pink veining.
Midnight Marvel: Pure red blooms glow against the rich purple foliage.
Starry Starry Nights: Foliage so dark it is almost black with seven to eight-inch flowers of pale pink with darker pink speckling and veining.
Rose of Sharon: Hibiscus syriacus is a woody plant hailing from southeast and south-central China and is sometimes called Althea shrub. It grows best in full sun, although it seems to tolerate afternoon shade just as well and makes a large shrub or even small multi-stemmed tree ten to twelve feet tall that can be artfully limbed up to create a focal point in the garden.
Rose of Sharon blooms on new wood, much like a rose does, so you have the option of hacking it down hard every spring if you need it to be more compact and lower growing.Traditionally, Rose of Sharon is a single flower (the classic hibiscus form like we think of from Hawaii only smaller) and in colors of white, pink, purple, and even blue. Over the years of course, breeders have developed double forms that look more like carnations and bi-color forms that often have deep purple throats. As a whole, I think they all have a rather tropical look.
Here are some of the newer choices on the market…
Full Blast: Large lavender flowers (three to four inches across) with rich, dark green foliage.
Bali: Semi-double pure white blooms with a purple-red center.
Tahiti: Semi-double fuchsia trumpet-shaped flowers with a dark red throat.
Fiji: Pink buds open to semi-double flowers with deep red centers.
French Cabaret: Several colors in this series, all with fully double flowers resembling pompoms.
Raspberry Smoothie: Again, fully double, much like a carnation, and fuchsia-raspberry in color.
Blueberry Smoothie: As above, only blush purple.
Strawberry Smoothie: Likewise, only light pink.
White Pillar: Pure white semi-double blooms on an upright, narrow growing plant that is ideal for a screen or hedge or even a thriller in a container. Grows only two to three feet wide and ten to fifteen feet tall.
Purple Pillar: Same as above, only with purple blooms.
Versailles: New from Monrovia Grower’s Chateau collection, this gem has large, showy, blue-violet flowers covering the stems from top to bottom, featuring a deep red-violet center. An improvement over the old timer “Blue Bird,” this blue flowering Rose of Sharon is proving to be a real highlight in the garden.
Any of the above varieties will give you years of enjoyment. Try a few this summer and see if you don’t fall in love with them.
Stay safe and keep on gardening!
Steve Smith is the owner of Sunnyside Nursery in Marysville, WA, and can be reached at firstname.lastname@example.org.
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