Guide to Hibiscus Laevis, (Halberd-Leaf Rose Mallow)

Hibiscus laevis (Halberd-leaf Rosemallow) is one of the most elegant flowers I’ve ever grown. Blooming large rose-like flowers in late summer, this tall beauty can really stand out amongst the crowd. This was one of the first native plants I grew back in 2013-2014, as I was quite taken with the pictures I could find online. And I felt that my small postage-stamp sized wildflower garden just had to have it!

So, after many years of experience I’ve come to know this plant well, and can share all that I’ve learned with you. How to grow it, where to grow it, and what to watch out for.

In this article:

• What is Hibiscus Laevis
• What are the benefits of Hibiscus Laevis
• Identification / Characteristics
• How to Grow and Care for Hibiscus Laevis
  • How to Grow Hibiscus Laevis from seed
• What Wildlife, Pests, and Diseases effect Hibiscus Laevis
• Where to buy Hibiscus Laevis
• Uses of Hibiscus Laevis

What is Hibiscus Laevis (Halberd-Leaf Rose Mallow)

Hibiscus laevis is a herbaceous perennial native to North America. Commonly known as Halberd-Leaf Rose Mallow, or just Rosemallow, it will grow 4′-6′ tall in full sun and medium to wet soil. A cold-hardy Hibiscus, it will bloom large 5″ diameter white to pink flowers for approximately 1 month from mid to late Summer. [1] [2] [3] [4]

Facts about Hibiscus Laevis

• Unlike it’s tropical cousins, Hibiscus Laevis can survive cold winters and come back every year as a perennial. It is cold-hardy to USDA zone 4.
• The common name “Halberd-Leaf Rose Mallow” comes from it’s 3-lobed leaves being shaped similar to the axe-heads of the ancient weapon, halberd, as the middle lobe is much longer than the side lobes.
• The leaves are either 3 or 5 lobed, the 3-lobed leaves looking like a mediveal weapon, while the 5-lobed leaves resemble a Maple leaf.
• Hibiscus laevis is a member of the Mallow family (Malvaceae)

Native Range of Hibiscus Laevis

The native range of Hibiscus laevis generally follows the rivers and lowlands of the Eastern half of North America. [3] In addition to the United States one location in Southern Ontario has documented the presence of Hibiscus laevis. [5]

Natural Habitat of Hibiscus laevis

Hibiscus laevis grows naturally along creeks, ponds, rivers, and is often found in wetlands. [3] It generally likes moist areas. I’ve seen it in areas that flood in Spring or Summer, and in open woods along mountain creeks.

Rose Mallow Reference Table

Scientific Name	Hibiscus laevis, (syn. Hibiscus militaris)
Common Name(s)	Rose Mallow, Halberd-Leaf Rosemallow
Native Range, USDA Zone	Eastern North America, Hardiness Zones 4-9
Bloom Time	August, September
Bloom Duration, Color	4 weeks, White to Pink
Height	4′-6′ (1.2 m-1.8m)
Spacing / Spread	2′-3′ (60-90 cm)
Light Requirements	Full Sun
Soil Types	Loam, Clay
Moisture	Medium-moist to wet
Fauna Associations / Larval Hosts	Butterflies, bees

What are the Benefits of Hibiscus Laevis

Beauty

The large white ornamental flowers of Hibiscus Laevis make for an elegant sight in any garden. If planted in groups, once can get an absolutely stunning display of white-pink flowers that are large enough to catch people’s eye.

Tough

These stout flowers can compete with most other flowers once established. The stout stems seem to stand tall though most storms (I’ve never seen one blown down). The flowers also stay erect and don’t seem to flop.

Clay Soil

Hibiscus laevis and it’s sturdy taproot have evolved to punch right through clay soil. I was amazed when I removed a couple of extra 2-year-old plants and just how widespread their root system was.

Wet Soil

One of the best plants for wetter areas and a natural wetland plant, Hibiscus laevis will look great along creeks, rivers, or any rain garden.

Identification and Characteristics of Hibiscus Laevis

Stalk

The robust stalk of Hibiscus laevis typically grows 3-6′ tall (90-180 cm) and will branch occasionally. It will be round, green, and smooth.

Leaf

The leaves of Hibicus laevis are generally 4″ wide by 6″ long, will have 3 or 5 pointed lobes, and are alternate along the stalk. [4] The 3 lobed leaves resemble a Halberd (hence the common name) while the 5-lobed leaves resemble a Maple or Sycamore leaf. The middle lobe is generally longer / more-prominent than the other lobes. [12]

There will be some leaf damage on this plant throughout the season. It usually isn’t too bad (except for Japanese Beetles). But remember, your native plants are helping feed your local ecosystem!

Flower

The flowers of Hibiscus laevis are large, up to 5″ diameter. As a general rule, the 5-petals will start pink in the center/throat and quickly transition to a white color. [12] Overall they are very showy.

Each stalk of the plant will have a single bloom open on a given day, and the flower of that bloom will only last one day. So, each new day during the blooming period a new flower will open while the previous days flower will close. Flowers are frequently visited by pollinators, but they also have the ability to self-pollinate. [6]

Blooming begins in mid-Summer and lasts for approximately one month. I’m in zone 6, and this generally occurs in late July through mid-August. After blooming, capsules will develop where the flowers once were, and large fuzzy seeds will be arranged in vertical lines, arrayed down the center (see photo).

Save Seed

You can easily save seed from hardy Hibiscus laevis by just collecting the seed heads once they turn brown. Then, dry them out for a week or so in a cool dry place out of the sun. Peel open the seed head to remove the small quasi-ball shaped fuzzy seeds. The seeds can be stored in an envelope or ziplock bag (if completely dry) for a year or two.

Important note on saving seed! Sometimes the seed of Hibiscus gets infested with small weevils. If you notice any tiny insects on or near the seed when saving it, consider placing the dried seed into a sealed container, and into the freezer for a week or two to kill any weevils.

Root system

The root system of Hibiscus laevis consists of multiple tap-roots that travel far from the plant. I learned this when I removed several specimens on Autumn. I was absolutely amazed at how much root mass the plant had generated in two years (see photo below).

How does Hibiscus laevis spread?

Hibiscus laevis only spreads by seeds, but it is not aggressive. I don’t believe I have ever had a ‘volunteer’ plant in all my years of growing it.

Lifecycle of Hibiscus laevis (Halberd-Leaf Rose Mallow)

In Autumn, the leaves of Hibiscus laevis turn a golden yellow before eventually fading to brown and falling off. In Winter, the seed heads and stalks will remain until Spring the following year.

See our image below to see what Hibiscus laevis looks like as a seedling, Spring, Summer, Winter, and Fall.

Grow and Care for Hibiscus Laevis

Sunlight Requirements

Hibiscus laevis grows in full sun (6+ hours of direct sunlight) or partial sun(4-6 hours of direct sunlight). It does not grow well in full shade.

Soil Requirements

For soil, Hibiscus laevis will grow best in finely textured or medium textured soils such as clay or loam. [3] It can grow in sandy loam if enough moisture is present, or it is compacted.

It will not grow well in very coarse sandy soils.

RELATED ==> 25 Plants that grow well in CLAY SOIL

Moisture Requirements

Hibiscus laevis prefers wet soils, and is a wetland plant. But it will also grow well in medium-moist soil. But, it can tolerate brief periods of drought due to it’s tap-root.

Pay attention to the plant, and if leaves start to yellow or get brown at the tips, then you should water it.

Maintenance

For maintenance, the only thing necessary is to cut the plant back in Autumn or Spring when dormant. As it is herbaceous, it will renew itself each year, and all above ground foliage will die each Winter (but remain standing).

Fertilizer

Hibiscus laevis shouldn’t require supplemental fertilizer. It should grow just fine as long as it’s sunlight and moisture requirements are met.

How to Grow Hibiscus Laevis from Seed

Hibiscus laevis requires a period of cold moist stratification. This requirement to break the seeds dormancy can be met by stratifying in the refrigerator or Winter Sowing the seed. Doing so will raise the germination rate substantially, as the seed may not germinate without going through a ‘over-wintering’ period.

To learn how to stratify using the refrigerator, see our guide. Also, we have a detailed guide and video on Winter Sowing.

Process to grow Hibiscus laevis from seed in containers

The following steps are for seed that is stratified, or for containers that will be Winter-Sowed.

1. Fill a container with moistened potting soil. Pack the soil firm, but leave a 1/2″ (12 mm) gap at the top. The soil should be moist, not wet. If you squeeze a handful, only a couple of drops of water should fall out.
2. Plant the Hibiscus laevis seeds 1/4″ deep (6 mm). TIP – use a pencil to make the hole.
3. Set the container in a location that receives morning sun and afternoon shade. This is a very important step, as the afternoon shade will help ensure that the seeds, and eventual seedlings won’t dry out in hot afternoon sun.
4. Germination should occur in Spring as evening temperatures warm up.

How to direct sow Hibiscus laevis seed

You can also direct sow Hibiscus laevis seed. It helps to have a disturbed or somewhat barren area. Otherwise more established plants could shade out the tiny seedlings.

In very wet areas, like the edge of a newly installed pond or disturbed area near water, you can just press seed into the soil, and lightly cover it with nearby dirt. If the area is somewhat uneven or fairly disturbed, you may even be able to just broadcast then walk on the seed.

How long to establish Rose Mallow from seed

The first year of Hibicus laevis’s life will be establishing a strong taproot system. The foliage may grow a couple of feet, but it will probably just resemble a green leafy bush. But by the second year of life, it will produce at least one flowering stalk (perhaps more). By the 3rd year, the plant should be fully mature, putting out 4-8 stalks with multiple flowers.

Wildlife, Pests, and Diseases associated with Hibiscus Laevis

Pollinators

Hibiscus laevis will attract many bumblebees, and even some specialty species such as the solitary ground-nesting Rose-Mallow Bee [7] as well as the bee Melitoma taurea [8]. The flowers also attract various species of butterflies and skippers.

Caterpillars of the Gray Hairstreak, Checkered Skipper, Painted Lady, and several moths feed on the foliage, sometimes voraciously.

Pests

Unfortunately, Hibiscus laevis is very susceptible to Japanese Beetle attacks. Before my Micro-prairie was established, I frequently had severe defoliation on this plant from being covered in Japanese Beetles. These attacks can severely damage the appearance of this plant.

I never treated the plant with insecticide. I can only attribute their decline over the last few years due to the more robust backyard ecosystem I’ve created with the numerous species of plants and the insects they attract. I figure that *something* is helping to keep them in check.

Deer and Rabbits

I’ve seen deer occasionally browse my Hibiscus laevis. But it does not seem to be preferred. This matches the reference information one can find from the USDA. [3]

Disease

As a general rule, Hibiscus laevis isn’t susceptible to disease. But, leaf-spot fungus can infect the plant if it is in too humid conditions without enough air movement. [9] [10]

Where you can buy Hibiscus Laevis

Hibiscus laevis is not typically sold in nurseries, as it isn’t a typical ‘garden friendly’ plant. But it can be purchased at specialty nurseries that deal in Native Plants. You can find native plant nurseries near you on our interactive map.

Where to buy seeds

We have ordered a variety of native flower seeds from Everwilde Farms, which you can order right from Amazon through our link on our RECOMMENDED PRODUCTS PAGE. (We may earn a small commission when you purchase through our links, at no cost to you. This helps support our website.)

Uses of Hibiscus Laevis

Garden Uses

Hibiscus laevis can fill several gardening roles that most plants cannot. It’s preference of wet soil make it an excellent choice for gardens near water, rain gardens, moist micro-prairies, and along creeks/ponds. [11]

Also, since Hibiscus laevis isn’t aggressive and doesn’t spread, it can be used in formal flowerbeds just the same. But make sure you place it in the back of the bed, as they can grow quite tall!

Companion plants

Any plant that likes to grow in full sun and moist soil can make a great companion plant for Hibiscus laevis. Some of the many native plants that prefer similar conditions include the following:

• Joe Pye Weed
• Ironweed
• Swamp Milkweed
• Golden Alexander
• Cardinal Flower
• Blue Lobelia
• Tall Sunflower
• Cup Plant
• Obedient Plant
• Bee Balm
• Turtlehead
• Liatris Spicata

Medicinal & Edible Uses

There are no documented medicinal nor edible uses for Hibiscus laevis in North American Ethnobotany. So, as precaution I would consider this plant non-edible.

Find more native plants here