Hardy Hibiscus, Rose Mallow, Swamp Mallow 'Moy Grande'

Hibiscus moscheutos

Family: Malvaceae (mal-VAY-see-ee) (Info)
Genus: Hibiscus (hi-BIS-kus) (Info)
Species: moscheutos (mos-KEW-tos) (Info)
Cultivar: Moy Grande
Hybridized by Dr. Moy
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36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 m)


4-6 ft. (1.2-1.8 m)


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:

Sun to Partial Shade

Bloom Color:


Bloom Time:

Mid Summer

Late Summer/Early Fall


Unknown - Tell us

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:

Unknown - Tell us

Propagation Methods:

From woody stem cuttings

From softwood cuttings

Seed Collecting:

Bag seedheads to capture ripening seed

Allow pods to dry on plant; break open to collect seeds

Foliage Color:

Unknown - Tell us

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:

Unknown - Tell us


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

Huntsville, Alabama

Tuskegee, Alabama

Alachua, Florida

Peoria, Illinois

Louisville, Kentucky

Brookeville, Maryland

Bluffton, South Carolina

Austin, Texas(3 reports)

Copperas Cove, Texas

Greenville, Texas

Iredell, Texas

Liberty Hill, Texas

Mc Kinney, Texas

Spicewood, Texas

Temple, Texas

Tyler, Texas

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Gardeners' Notes:


On Jul 28, 2010, braun06 from Irving, TX (Zone 8a) wrote:

Moy Grande ranks at the top of the selections for me. I like the foliage/stem color and the big nicely colored flowers. The foliage also has nice substance and a shape I appreciate. The first flowers of the season open bigger than in following flushes. I have not had as good repeat with this cultivar as with the red Lord Baltimore. Lord Baltimore blooms earlier and continuously whereas my Moy Grande bloomed for 3 weeks then seemed to take a break. I like this plant a lot but have decided to remove it in place of more japanese beetle resistant plants. The beetles love perennial hibiscus flowers/leaves and are active the same periods this thing is in flower.


On Oct 7, 2008, LiliMerci from North of Atlanta, GA (Zone 8a) wrote:

Several years ago, Dr. Jerry Parsons, Extension Horticulturist located in San Antonio, released a new giant rose mallow named 'Moy Grande' from the San Antonio Botanical Garden. 'Moy Grande' has huge flowers of dark rosy pink. Best availability is in the San Antonio area


On Oct 1, 2004, CaptMicha from Brookeville, MD (Zone 7a) wrote:

I'm growing three of these guys and I'm very pleased. They put on flowers the first year from seed, fairly early in the season and they're still free flowering even it's starting to get cold, I expect flowers up until frost.

The flowers are HUGE, I measured one at 9" today. The over all plant has a nice round shape. I can't comment on the hardiness but will try to update next spring if they make it through the winter.

Update 2008: These plants are very hardy in my zone 7. They're a bit slow to come up in the spring but the wait is worth it. I've found out that if I want to get to enjoy the plants at all, I have to spray it or they get utterly destroyed by Hibiscus Sawfly larvae. Also, since the time my plants turned 2 or 3, they lean drastically, despite wheth... read more


On Jul 13, 2004, clantonnaomi from Iredell, TX wrote:

I have three of these plants and they have done very well in central Texas (Zone 8). They grow in full sun with very little care and the blooms on them are at least 15 inches across. They are very large plants - one of mine is over 5 feet tall and wide. I highly recommend them - everyone who sees mine says "I have to get one of those!"


On Jul 10, 2004, sweezel from McKinney, TX (Zone 8a) wrote:

Actually a cross between Hibiscus grandiflorus and Hibiscus mocheutos 'Southern Belle'. Ying Doon Moy, research and development horticulturist at the San Antonio Botanical Center, cross-bred the two.

Great plant for bad drainage areas. I have this growing in an area where all the water from mine and my neighbors backyard drain. It is in a corner of fence that maybe gets 4 to 5 hours of mid-day sun. It is also very thick black gumbo clay and this plant seems to love it. The bloom stems do seem to droop a little more than other pics I see, but compared to what other plants would do in the same condition, this plant is perfect. It was put in last September and has hit 5 feet tall now in July.


On Mar 5, 2003, IlonaGordon from San Antonio, TX wrote:

We live in San Antonio and have 2 plants that grew to over 6' last year in about 3-4 months, from shoots under the ground (they had died back the previous winter). They have dark pink dinner plate size blooms (about 20-25 per plant)all summer and into Fall. They should be planted at least 6-8' feet apart. We have propagated some from cuttings and will see if they are still OK this Spring. I believe they should be propagated from cuttings, as the seeds are not true in hibiscus. See pictures.