Swamp mallow (Hibiscus moscheutos), also known as rose mallow hibiscus or swamp hibiscus, is a shrubby, moisture loving plant in the hibiscus family that provides big, showy flowers from midsummer to autumn. The plant performs well along pond edges or other damp areas. This stunning, low-maintenance plant is available in a range of colors, including pink, peach, white, red, lavender, and bi-color varieties.
How to Grow Rose Mallow
The easiest way to grow rose mallow is to purchase a plant at a garden center or nursery. However, growing rose mallow by seed isn’t difficult. Start seeds indoors eight to ten weeks before the last frost in your area or plant seeds directly in the garden after the last killing frost in spring.
Rose mallow benefits from rich soil amended with at least 2 or 3 inches (5-8 cm.) of compost, manure, or other organic material. Locate the plant in full sunlight. Although rose mallow tolerates partial shade, too much shade may result in leggy plants that are more susceptible to insect infestations.
Allow at least 36 inches (92 cm.) of growing space between each plant. Crowding the plant inhibits air circulation which may result in leaf spots, rust, or other diseases.
Swamp Hibiscus Care
Swamp hibiscus plants are water-loving plants that will stop blooming in dry soil. However, the plant, which dies and enters a dormant period in winter, shouldn’t be watered until it displays new growth in spring. Once the plant is actively growing, it needs a deep watering two or three times per week during warm weather.
Water is especially important during the first growing season, but the plant should always be watered immediately if it shows signs of wilt.
Feed rose mallow every six to eight weeks during the growing season, using a balanced, water-soluble plant fertilizer. Alternatively, use a slow-release fertilizer after the plant breaks dormancy in spring.
Spread 2 or 3 inches (5-8 cm.) of mulch around the plant to keep the roots moist and cool, and to keep weeds in check.
Spray swamp mallow with insecticidal soap spray if the plant is damaged by pests such as aphids, whiteflies, or scale.