Hibiscus x 'Akata88' RAIJIN® swamp mallow, hardy hibiscus

RAIJIN® is a Japanese variety of hybrid hibiscus bred by Yukio Kurabayashi from Tokyo's Akatsuka Botanical Garden. It is a cross between h. moscheutos and h. coccineus and it was first introduced at the prestigious novelty fair Plantarium in Boskoop, the Netherlands, in 2019. European Patent No. 59680 was granted in 2022.

RAIJIN® hibiscus bears bright red flowers which are slightly smaller compared to most other hybrid hibiscus varieties, yet they are impossible to miss being up to 15 cm across. They bloom from August and depending on the age of the plants they can bloom until October as long as the weather is warm and sunny. Flowers lack fragrance just like all other hibiscus. The deciduous leaves are no less attractive, they are 3-lobed, deeply incised, bright green in summer and golden orange and yellow in autumn. RAIJIN® hibiscus makes well-branched perennials of about half a meter in height, which makes it suitable for outdoor containers. In a garden bed with ideal conditions – moist to wet soil with enough nutrients, its height can double with age.

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 plant 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 at the end of 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 must be fertile and permeable, never let it dry out in summer. Hardy to min. -29 °C (USDA zone 5), possibly more. Cut back the plant only a few centimetres above ground level in spring.

Last update 01-03-2023