Hardy Hibiscus

Having had a big interest in these plants for many years, it is great to see so many improvements in both seed and vegetative “hardy” hibiscus. Most growers will identify with the Disco Belle series that basically took over the market about 20 years ago and has had little competition since. Connoisseurs of the hibiscus will know about some of the great species forms floating around in the industry, and for those of you who have no idea what I am talking about we’ll do a little history and get you caught up…

The only good thing to come out of the “disco” movement in the 70s was the release of the seed-produced Disco Belle Series of hybrid Hibiscus moscheutos. Disco Belles grabbed the American gardener’s attention with big (12-inch) blooms, flashy colors and a feeling of success for doing very little. In garden plants these qualities are good, and Disco Belle was a great series.

What’s New

The Vintage line of hardy hibiscus was unveiled at the OFA Short Course this summer, and there is some great new genetics here. The Vintage line is composed of the Carafe and Splash series from Yoder Brothers/Green Leaf Perennials, bred by Mark Smith. All of these plants are compact compared to the species and have greatly improved branching. The Carafe series is approximately 3 feet tall with three colors: Bordeaux (deep pink-red), Chablis (pure white) and Grenache (pure pink). The Splash series, with two colors — Pinot Noir (red) and Pinot Grigio (light blush) — is the most compact, at 2-3 feet mature height and again great branching. The plants are supplied only as a rooted liner and are not dormant but vigorously growing, so bench time for the crop is significantly reduced. These series reflect major improvements on the vegetative side of this crop, with great growth habit and flowering!

The Luna series from PanAmerican Seed is a great 2003 seed-grown release with two colors: Red and Blush (white with pale pink edges and overlay). The Luna series is extremely compact (2-3 feet mature height) and uniform, with a slightly lighter green foliage than some of the old-fashioned types. For seed production this is a big improvement over Disco Belles.

Don’t forget the species of hibiscus that are less common, but no less impressive. Recently H. acetosella has become popular as a foliage color-annual in plantings around the United States, but there are plenty of great perennials as well. H. grandiflora is a native species of the Southeastern United States and has rich, fuzzy, gray-green leaves on a plant that reaches up to 15 feet high. Salt tolerant, this species also grows in brackish water directly in the tidal zones. Flowers of H. grandiflora are approximately 8-10 inches across and a clear soft pink color. H. coccineus, the swamp or marshmallow hibiscus (I love common names), is most commonly a clear red color with petals that don’t overlap, but the range of forms and closely related species will vary a lot. If you are looking for native plant species to grow and plants with a crossover to water gardening the marshmallows are a great crop. H. mutabilis is an old-fashioned garden plant of the Southern United States that goes by the name ‘Confederate Rose’, this might be the reason it never really caught on in the North; still, this very upright, tree-like species produces 6- to 8-inch double blooms that open white and fade to pink. While a woody perennial in the South, this species still makes a very striking annual for Northern gardens. A sub-form of this species H. mutabilis ‘Rubra’ is a smaller stature plant with single (usually 4-6 inches), intense deep pink to carmine blooms.

Whether you are looking at new hybrids, old hybrids or species the main thing to remember with the hardy hibiscus is high light and generous spacing. Control stretch and growth by reducing fertility and watering as well as using PGRs. You can sell every one of these plants that has a flower on it, but customer satisfaction depends on how good a job you did producing a strong plant during the container phase of production. These plants are tough, dramatic and hardy over most of the United States but are rarely grown at high quality due to their speed of growth and vigor.

Most people discover their first hardy hibiscus in someone else’s yard because the plant has enough room to reach its full potential; containers in retail nurseries are often small and stashed away in the shrub section rather than out where their color can really help move the material. It is a market that good growers can make a lot of money in, and average growers can usually sell everything they grow. Hardy hibiscus is the Á perfect centerpiece plant in large mixed containers and makes awesome specimen containers as well. The bigger the container, the bigger the impact they make. The biggest problem with these plants is their vigor and tendency to stretch (in a big way) when crowded or grown under lower light levels.