BattenBlooms
PL. —Hibiscus moscheutosBotanical illustration — drop image
Hibiscus moscheutos

Hardy Hibiscus

SummerFall
4a–9bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Not in bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Hardy hibiscus (swamp rose mallow) is the most dramatic perennial in the late-summer garden — enormous dinner-plate-sized flowers up to 12 inches across in shades of red, pink, white, and bicolor, on shrub-like plants. It is a native of wet meadows and tolerates conditions that would kill most perennials: saturated soils, clay, flooding. It emerges late in spring — don't panic when others are up and yours isn't.

The individual flowers last only one day, but a mature plant in full summer production carries many buds that open in succession. For cutting, harvest buds in the late afternoon just before they are about to open the following morning. The blooms will open indoors in a warm room and hold beautifully for their day.

Good companions
Vernonia giganteaMonarda didyma
Care guide
SunFull sun — 6+ hours; fewer blooms in shade
WaterRegular to abundant; native to wet meadows and edges
SoilRich, moist, tolerates wet; clay soils are fine
Spacing3–5 feet
Height3–8 feet
Zone4a – 9b
Native RegionAL, AR, CT, DC, DE, FL, GA, IL, IN, KS, KY, LA, MA, MD, MI, MN, MO, MS, NC, NJ, NY, OH, OK, PA, RI, SC, TN, TX, VA, WI, WV
Frost hardy
Seasonal tasks
spring
watchDo not panic in spring — hardy hibiscus emerges very late, often in May
summer
cutHarvest swelling buds in late afternoon to open indoors the following morning
watchJapanese beetles are the primary pest — hand-pick in morning when sluggish
fall
cutCut back to 6 inches in late autumn after frost kills the foliage
Common problems

Aphids

Symptoms

Clusters of small soft insects on new growth and flower buds.

Treatment

Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.