Check out the sunny wet areas along our roadsides and you can’t miss them. This early July heat is speeding their maturity, but they look like they are hanging tough. Huge white or pink blooms now adorn our landscape. Individual flowers have five equal petals and can be eight inches across.
Rose mallow, sometimes called perennial hibiscus or wild cotton, is a fast growing perennial that can grow up to seven feet tall. Plants die back to the ground each year. Stems are somewhat hairy and sport large toothed edged leaves with reddish veins which are triangular to heart-shaped. Close botanical relatives are hollyhock, rose of Sharon, tropical hibiscus, okra, and cotton.
Perennial hibiscuses are gorgeous on our roadsides and can make colorful additions to our gardens. They are long lived and attract butterflies and hummingbirds. Blooming from late June to early September, color can be quite prolific if old flowers are removed. Seeds ripen from August to October and can be collected and planted in our gardens in the spring.
This perennial is great for sunny areas with moist soil. They tolerate a wide pH range. The huge blooms make a stunning backdrop when used with shorter plants. Rose mallow is not overly invasive and won’t take over an area like some tall perennials can.
They are often late to emerge in spring, so don’t get concerned if they are late to show themselves. That might even be an advantage when planted with early spring bulbs like daffodils. The simple fact that mallows thrive in wet areas may be enough for some gardeners to try them.
Japanese beetles, aphids and a few species of moths are common pests, but severe infestations are rare. Bacterial leaf spot and gray mold can sometimes be a problem too, but plants are relatively disease resistant. These perennial hibiscuses aren’t as prone to scale as the tropical types either and since they die down to the ground each year they don’t provide protection for overwintering pests.
Flowers are edible and make a pleasing mild tea high in vitamin C. It is used medicinally to treat urinary problems. It has strong diuretic properties, thus increases urine flow.
Leaf extracts are even used in some shampoos. Numerous claims boast that chemicals in the hibiscus improve hair strength and the mucilage is good for the skin. Hibiscus extracts have been used externally to treat eczema. Leaf mucilage would thicken soups and sauces if used in them. Foliage is somewhat hairy and quite bland and not used much for that purpose, but no parts of the plant are poisonous.
Other Hibiscus species are used in commercial herb teas. You can even use rose of Sharon and the tropical type hibiscus too. Some use the leaves as a garnish or in salads. A related species common in Florida is prescribed successfully to treat hypertension. That shows great promise, but like with any medicinal herb we must pay attention to medications we take that might counteract or accentuate the results.
Ted Manzer teaches agriculture at Northeastern High School.