Hibiscus moscheutos EXTREME RED swamp mallow, hardy hibiscus
size/type
mid-sized perennial,mid-sized perennial
usual height
0,5-0,8m
usual width
0,5-0,8m
leaves
deciduous broadleaf
colour of leaves
flowers
showy
colour of flowers
blooming time
August-October
location
full sun
USDA zone (lowest)
5b (down to -27°C)
winter protection
for zone 5+6
for zone 7
categorized
Swamp mallow and its hybrids have been sought after plants for the past few years now. They are perennials with sturdy stems that have large, tropically looking flowers. Dutch company Apartus offers a series of large-flowered varieties called SUNIQ® XXL.
Description of the plant:
EXTREME RED is a swamp mallow variety with very large flowers. They are rich red (not dark purple or magenta, really red), and 16-17 cm across. Flowering begins in August and depending on plant's age and fertilizing new flower buds can be formed till September or October. Deciduous leaves are deep green, heart-shaped with a long, narrow tip, and in autumn turn amber orange with red veins. Stalks and stems are pink flushed. The breeder claims an overall plant height of 50-60 cm, however, hardy hibiscus sizes can vary a great deal with location so count on a little less in poor or compacted or sandy ground, and perhaps a lot more in fertile, moist or wet ground.
The plant is dependent on regular watering and feed supply. Use fertilizers with enough phosphorus for abundant flowering, or any other quick-release fertilizers where nitrogen is not predominant. Any fertilizing has to stop by end September. Still, nitrogen-based fertilizer is useful when the plants wakes up from dormancy in mid spring, but should not be used longer than 8 weeks. Hardy hibiscus emerges very late, sometimes as late as in late May.
For healthy growth and profuse flowering it needs a sunny location with a lot of moisture which can be achieved by good mulching. The soil has to be fertile and permeable, never let it dry out either in summer or during dry winters - its fleshy roots need some moisture also in winter. Hardy to about -27°C (USDA zone 5b). Cut back the plant only a few centimetres above ground level in spring.
Last update 14-06-2019
