Information About Swamp Hibiscus


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Swamp Hibiscus Plant Info: How To Grow Rose Mallow Hibiscus

By Mary H. Dyer, Credentialed Garden Writer

Swamp mallow, also known as rose mallow hibiscus or swamp hibiscus, is a shrubby, moisture loving plant that provides big, showy flowers from mid-summer to autumn. Learn how to grow and care for this plant in the article that follows.


Hibiscus without the fuss: Alan Titchmarsh's tips on growing this late-summer stunner

PLANT this shrub in your garden’s sunniest spot, in well-drained soil, and it should prove to be a trouble-free late-summer stunner.

Hibiscus is not that tricky to grow, provided you have a warm, sheltered, sunny spot

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Is it dead? That’s the question I frequently hear in relation to one particular shrub. It’s a beauty that you might have seen on holiday in the Mediterranean or the Caribbean – or at least you might have seen its near relation.

Hibiscus is not that tricky to grow, provided you have a warm, sheltered, sunny spot in well-drained soil. But it is rather late coming into leaf – hence that frequently asked question.

It may be as late as June before a hibiscus starts to unfurl its bright green foliage, but from then on it shows its true worth as a late-flowering shrub.

The species that grows in the warmer countries is Hibiscus rosa-sinensis, which is too tender to grow outdoors in the UK. Our winters would rapidly see it off.

But Hibiscus syriacus is altogether tougher and is available in a wider colour range than its softer counterpart. ‘Blue Bird’ (or ‘oiseau bleu’ if you are feeling continental) is a rich lavender blue, ‘Red Heart’ is white with a pronounced crimson “eye”, and the favourite ‘Woodbridge’ is deep rose pink with a mauve “eye”.

The habit of these hibiscus shrubs is upright and fairly stiff, so they need nothing by way of support. Nor do they need much pruning, since they are relatively slow growing and unlikely to grow so large that they become a nuisance – not before many years have elapsed at any rate.

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In time they will make shrubs 6ft tall and 3ft across, which means they can fit into the smallest of gardens and, come late summer when many other blooms have given their all, your hardy hibiscus flowers will be a welcome refresher.

Buy a plant in full bloom right now so you can see what you are getting, and position it in the sunniest spot possible in soil that does not stay soggy.

When pruning you can go easy with the secateurs. It needs no regular attention, other than the removal of any badly placed shoots or any that die back.

But that’s looking on the black side. Given the right spot, the hibiscus is one of the most trouble-free shrubs I know, provided you can be patient enough to resist digging it up if those leaves are a little slow to open.

Believe me, the plant will make up for it later.


Hardy Hibiscus, Rose Mallow, Swamp Mallow 'Plum Crazy'

Family: Malvaceae (mal-VAY-see-ee) (Info)
Genus: Hibiscus (hi-BIS-kus) (Info)
Species: moscheutos (mos-KEW-tos) (Info)
Cultivar: Plum Crazy
Additional cultivar information:(PP11854)
Hybridized by Zwetzig-Fleming
Registered or introduced: 1999
» View all varieties of Hibiscus

Height:

Spacing:

Hardiness:

USDA Zone 5a: to -28.8 °C (-20 °F)

USDA Zone 5b: to -26.1 °C (-15 °F)

USDA Zone 6a: to -23.3 °C (-10 °F)

USDA Zone 6b: to -20.5 °C (-5 °F)

USDA Zone 7a: to -17.7 °C (0 °F)

USDA Zone 7b: to -14.9 °C (5 °F)

USDA Zone 8a: to -12.2 °C (10 °F)

USDA Zone 8b: to -9.4 °C (15 °F)

USDA Zone 9a: to -6.6 °C (20 °F)

USDA Zone 9b: to -3.8 °C (25 °F)

Sun Exposure:

Bloom Color:

Bloom Time:

Foliage:

Other details:

Soil pH requirements:

Patent Information:

Propagation Methods:

From herbaceous stem cuttings

Seed Collecting:

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed

Foliage Color:

Bloom Characteristics:

Water Requirements:

Average Water Needs Water regularly do not overwater

Where to Grow:

Regional

This plant is said to grow outdoors in the following regions:

Gardeners' Notes:

On Jan 13, 2014, tumorgrrrrl from McKinney, TX wrote:

Those who are trying to trade seeds or cuttings of this plant should know that it is patented (PP 11854), which means that even trading of this plant for free is prohibited. I don't know the developers, I'm just a firm believer in copyright, whatever it's forms.

On Apr 1, 2008, tabasco from Cincinnati (Anderson Twp), OH (Zone 6a) wrote:

'Plum Crazy' is an elegant plummy colored perennial hybrid hibiscus introduced by the Fleming Brothers of Lincoln, Nebraska. The Flemings are famous for having produced several 'rose mallow' hybrids that are are typically crosses of H. moscheutos and H. coccineus varieties, and which are hardy to as far north as Zones 4 and even 3 (with pine bark winter mulches recommended).

We have enjoyed two 'Plum Crazy' hibiscus in a sunny low spot in a front garden for two years and I couldn't do with out them. They are wonderful plants that emerge from dormancy in late spring and don't begin to bloom until July, so they make nice companion plants for spring blooming bulbs, campanulas, and siberian iris. Others recommend planting 'Plum Crazy' with a selection of tall grasses. Whil. read more e the Fleming hibiscus don't like 'wet feet' they do require regular watering, either natural or irrigation.

"Plum Crazy" is a heavy feeder and likes monthly feedings of garden fertilizer until June. From June on, a fertilizer light on the nitrogen is preferred. The Fleming hibiscus are bred to be shorter and more compact ('Plum Crazy' is 4' x 3' according to the Fleming site) than the old fashioned garden hibiscus and may not need pruning unless you choose to. Some gardeners like to pinch out the early tips of perennial hibiscus to promote a bushier plant and more blooms. I have not done this in previous summers, but I may try it this year to create a 'show case' plant.

This hibiscus will stop blooming and die back after the first frosts. I did not cut them back immediatedly in the fall but waited until early spring to cut back to promote plant health and re-emergence in the late spring.

Perennial hibiscus are often easily propagated by cuttings taken from plants in early summer, dosed with a bit of rooting hormone and situated in growing medium or water, however, 'Plum Crazy' is patent protected and propagation is restricted.

I love this particular hibiscus. It is elegantly shaped with beautiful plum tinted leaves and flowers that are proportional to the leaves and stems and other plants in the garden. It is readily available at better perennial nurseries and on the internet. I purchased large plants at an end of season sale for $10 each. Now that I know how lovely they are to have in the garden I would have paid much more!


Hardy Hibiscus, Rose Mallow, Swamp Mallow 'Disco Belle Pink'

Height:

Spacing:

Hardiness:

USDA Zone 5a: to -28.8 °C (-20 °F)

USDA Zone 5b: to -26.1 °C (-15 °F)

USDA Zone 6a: to -23.3 °C (-10 °F)

USDA Zone 6b: to -20.5 °C (-5 °F)

USDA Zone 7a: to -17.7 °C (0 °F)

USDA Zone 7b: to -14.9 °C (5 °F)

USDA Zone 8a: to -12.2 °C (10 °F)

USDA Zone 8b: to -9.4 °C (15 °F)

USDA Zone 9a: to -6.6 °C (20 °F)

USDA Zone 9b: to -3.8 °C (25 °F)

USDA Zone 10a: to -1.1 °C (30 °F)

USDA Zone 10b: to 1.7 °C (35 °F)

Sun Exposure:

Bloom Color:

Bloom Time:

Foliage:

Other details:

Soil pH requirements:

Patent Information:

Propagation Methods:

From herbaceous stem cuttings

From seed sow indoors before last frost

From seed direct sow after last frost

Seed Collecting:

Allow pods to dry on plant break open to collect seeds

Foliage Color:

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs Water regularly do not overwater

Where to Grow:

Regional

This plant is said to grow outdoors in the following regions:

Dearborn Heights, Michigan

Minneapolis, Minnesota(2 reports)

Thomasville, North Carolina

North Smithfield, Rhode Island

Gardeners' Notes:

On Apr 22, 2008, DallasDad from Murphy, TX (Zone 8a) wrote:

I've planted about twenty of these here just northeast of Dallas. They are very slow growing until the weather warms up. They like good-drainage, and don't seem to like clay very much. The ones I planted in planters with good potting soil are doing much better than the ones in the ground. However, only the summer will tell for sure.

On Aug 30, 2006, younggardener from Indianola, IA (Zone 5a) wrote:

This is by far my favorite flower. I have four hibiscus plants, including this cultivar. I love them so much and the just keep on blooming endlessly! :)

On May 16, 2006, gardenbeads from Warren, MI (Zone 5a) wrote:

This is a very beautiful hibiscus. The flowers are as big as small dinner plates. People keep asking me "What kind of flower is that?" as it is not a common plant grown in Michigan. It overwinters just fine and provides flowers from the end of July through to September if you give it some bloom booster before it flowers. Just remember not to overwater as the leaves will turn yellow and the buds will fall off. It prefers a drier spot and likes the heat.

On Apr 7, 2005, traceyh from Hurley, NY wrote:

This is a real show-stopper in New York. People don't expect to see hibiscus here. My first year with this plant, I was shocked at how long it remained dormant. It stays asleep even longer than Rose of Sharon. Mine did not show signs of life until June 1st. Then it just shot up. It is worth the wait!

On Jun 4, 2004, okus from (Zone 8b) wrote:

The flower is huge, but I would describe the bloom colour as white blushed pink with red center. The plant seems to weather 70mph wids well too


Watch the video: Take a Walk with Tavia #35 - Swamp Hibiscus


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