'Disco Belle Red' Hardy Hibiscus;
aka, Rose Mallow or Swamp Mallow
"My glance, home-gazing, scarce discerns
This listless girl, in whose dark hair
A starry red hibiscus burns;
Her pallid cheeks are like a pair
Of nuns, bloom-ravished, yet so fair."
-Walter Murdoch
(1874-1970)
(1874-1970)
'Disco Belle' rose mallows constitute a series of semi-dwarf Hibiscus moscheutos (synonymous with Abelmoschus moscheutos) derived from the much taller 'Southern Belle' group, most of the latter growing to five feet. 'Disco Belle' rose mallows, hardy hibiscus, or swamp mallows grow to two or two & a half feet tall, but with blooms nearly as enormous as for the taller 'Southern Belle' series.
Disco Belles come in pure white, white with pink blushed edges, light pink with red-pink eye, dark pink, & red to maroon-red. We have two; both are the blood or maroon red. 'Disco Belle' is recommended for seasonal hedges that vanish in winter, butterfly garden, hummingbird garden, or mixed perennial borders or filler between shrubs. It is not for the cutting garden because each flower lasts only a day or a day & a half & are useless for bouquets, though in the garden rose mallows are prodigious in the number of blossoms continuously produced.
Plants from this series are seed-grown F1 hybrids much showier than the already showy species. This series dominates the market for hybrid hardy hibiscus, & the newer cultivar series 'Luna' consisting of two colors (red & white) is improved mainly for seed production rather than appearance, so 'Disco Belle' will likely continue to dominate for some while to come.
Whether started from seeds or purchased as small bedding starts, the color one ends up with is hit & miss. It is sometimes possible to buy them in summer with buds beginning to open to judge preferred colors, but they prefer to be planted out in spring to get their root system well established before they start flowering mid to late summer. If planted later in the year they will expend energy on their blooms, not develop a big enough root system, & be more apt to die in winter, though autumn-planted rose mallows could be protected by mulching their first year.
They can be started in February from seed indoors or in a warm greenhouse in individual pots, & put in their permanent locations outdoors in April or after the last threat of frost.
If buying young plants in the nursery in spring, they will be leaves only, which are not often impressive looking. Don't be discouraged; they'll look way better once they get established in the garden, & really should be planted well ahead of blooming. Select them for general health & the most branchings.
Blooms appear mid-summer & last into early autumn or until the first good frost. Blooms are typically eight to ten inches across, big as picnic paper plates or colorful crepe paper caps at a child's party.
The semi-dwarf 'Disco Belle' is an improvement over the rangy easily sunburnt & windburnt foliage of the species. But even for this tough compact garden form, the large leaves can be scruffy during the bloom season, so the best locations for rose mallows are at the back of the garden array where the large blooms will make themselves seen but the leaves somewhat hidden.
Leaves will be more inclined to hold better appearance after a big root system is established & if the clumps never experience droughtiness or exposure to drying wind. Rose mallows want full sun or at most just a little afternoon shade. They are subject to windburn mainly for the leaves but the huge flowers can be prematurely blown into shapelessness by too much windiness, so a protected location is best.
For plant structure they can look a bit like sturdy erect woody shrub mallows (for example, Lavatera thuringiaca 'Burgundy Wine') or like Rose-of-Sharon hibiscus (Hibiscus syriacus), having thick stems & bushy appearance. But those woody-seeming stems are hollow & lightweight & rose mallows die back in winter. In this regard their behavior is more like High Mallow (Malva sylvestris) or Hollyhocks (Alcea rosea) but not as drought-hardy but longer lived than either. All of these have rather similar summer flowers, with those for rose mallows largest.
Any remaining woody stems should be clipped away to within four to eight inches of the ground as soon as they are browned & obviously dead. The clump will be very slow to return the following spring. Shoots will appear by May if the ground is directly warmed by the sun; otherwise it can be unnoticeable until early June, for they wait until very warm days to get restarted. Once they start, though, they are swift & vigorous in their belated growth spurt.
Their location should be well marked so that their spot isn't mistaken for an unplanted area & accidentally dug up. They are good companions for early-spring blooming bulbs such as waterlily tulips or early daffodils, since early daffodils will be dying back as the rose mallows are getting started.
Originating as a native stream-side & swampland wildflower of eastern to southern North America, in the garden they want evenly moist well-drained soil, & in particular should not experience drought at high summer when they're eager to bloom. Their first year in the ground they'll need more water than they will thereafter. Although overwatering can be harmful too, sometimes they will do quite well in a spot that stays too wet for most perennials. If soil dries out entirely the leaves will soon look scorched or spotty. Rose mallow can also benefit from regular fertilizing to flower maximumly & keep reflowering.
In zones 5-8 they should perennialize easily & prove themselves long-lived. In colder zones where the ground freezes in winter, it is advisable to hill rose mallows to a foot depth, as is often done for roses in freezing climates. Alternatively in zones 3-4, they should be dug up with plenty of soil around their deep root system & stored in a cool but frost-free basement or potato cellar.