Hardy Hibiscus, Rose Mallow, Swamp Mallow 'Robert Fleming'

Hibiscus moscheutos

Family: Malvaceae (mal-VAY-see-ee) (Info)
Genus: Hibiscus (hi-BIS-kus) (Info)
Species: moscheutos (mos-KEW-tos) (Info)
Cultivar: Robert Fleming
Additional cultivar information:(PP14776)
Hybridized by Fleming-Zwetzig
Registered or introduced: 2001
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4-6 ft. (1.2-1.8 m)


24-36 in. (60-90 cm)


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:

Full Sun

Bloom Color:


Bloom Time:

Mid Summer

Late Summer/Early Fall



Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

By dividing the rootball

Seed Collecting:

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

Foliage Color:

Unknown - Tell us

Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


This plant has been said to grow in the following regions:

Crown Point, Indiana

Farmersburg, Indiana

Indianapolis, Indiana

Allentown, Pennsylvania

Philadelphia, Pennsylvania

Austin, Texas

Temple, Texas

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Gardeners' Notes:


On Sep 17, 2013, keferraro from Crown Point, IN wrote:

I bought 'Robert Fleming' on clearance at the end of June, put it in the ground in a new garden area and it has done nothing but fabulous ever since. The foliage is great, dark, dark green with red tinged stems; the flowers are prolific to the point of non-stop, beautiful deep red/maroon flowers, every time I look I see more buds coming. The flowers and the plant are smaller than the 'Kopper King' that I have had for many years but it is a much more prolific and pleasing plant. 'Kopper King' stopped blooming weeks ago and the foliage looks drab but 'Robert Fleming' looks better than ever. I am sure it will keep on that way until the frost gets it. The challenge is to find equally pleasing late bloomers to accompany it. I'll be moving my coreopsis 'Creme Brle' over there as it is as reli... read more


On Aug 8, 2013, marsrover from Allentown, PA wrote:

I acquired my Robert Fleming two years ago, and it has become my favorite of my three hibiscuses (Lord Baltimore, Fantasia and Robert). They are among the last plants to emerge in spring. Other than sawflies, nothing seems to bother them. But, Bob's color sets it apart. It also has more petal texture than the Lord Baltimore. Begins blooming in late July and keeps going into September. Flowers last about a day, but it is so prolific that there are always flowers on the plant. Bob is shorter than the other two, but still needs some support to stay upright. Bees and wasps love it. A great plant.


On Sep 30, 2009, jeffeljefe from Philadelphia, PA (Zone 6b) wrote:

I bought this around June and it's been in a pot on my front step that gets afternoon/setting sun. Nice big blooms that last for one to two days at full mast and are quickly replaced by new ones after they fade. Every so often a day or two will go by with no blooms but it has been blooming prolifically all summer and now into the fall.