Summers just wouldn’t be the same without hibiscus flowers. Hibiscus create the feeling of some tropical paradise — even in city centers. Those of you who have balcony gardens can easily cultivate a number of hibiscus species.
|Wild Hibiscus mutabilis on the Yakushima Coast|
The golden rule for growing hibiscus is to ensure they have ample sunshine, moist and fertile soil, plenty of water and regular feeding throughout the growing season. They can be grown in pots or in the garden in a sunny position. On my own balcony I cultivate three species of these lovely flowering plants. They are the rose of Sharon (mukuge, H. syriacus), the confederate rose (fuyo, H. mutabilis) and the scarlet rose mallow (momiji-aoi, H. coccineus).
Hibiscus belongs to the mallow family (aoi-ka, Malvaceae). Worldwide, there are estimated to be around 300 species distributed throughout warm temperate zones and the tropics.
|The scarlet rose mallow is an ideal balcony plant.|
Here in Japan, the most popular garden hibiscus is the rose of Sharon. Though native to China, this species has been cultivated here for hundreds of years. It is a deciduous shrub and will grow 3-4 meters high in gardens. The flowers, 5-6 cm across, are borne at the tips of branches, and its colors include white, red, yellow or bluish, with maroon spots or blotches on the base petals. Individual flowers have five separate petals.
Some varieties of the rose of Sharon have double flowers, although my personal preference is for a single flower because of their clear, simple appearance. Mature bushes are drought-resistant.
Cultivating the rose of Sharon is simple: Use any well-draining garden soil. Also easy to grow in containers, small potted plants are a better buy than than large bushes. The small plant is naturally much cheaper, but also more vigorous than tall, stately looking plants. A plant-when-small rule applies to all garden plants.
To keep potted plants healthy, repot or change the soil every two to three years. During winter, cut back the previous season’s growth to the lowest two buds on branches.
For this, I favor Felco secateurs. These high-quality, Swiss-made secateurs are readily available in Japan in some 10 varieties, including secateurs for left-handed people.
The confederate rose is another common shrub, growing to a height of 1-4 meters. Its leaves are large, with three to seven lobes. In Japan, this deciduous shrub is native to coastal areas in Kochi Prefecture, southern Kyushu and Okinawa. Outside Japan, it is native to China and Taiwan.
In colder areas, the confederate rose can be treated like a perennial, which means that the branches may die completely back to the base or to a short trunk from which new branches shoot the following spring. Confederate rose hibiscus flowers are 10-20 cm across and are normally pale pink. They also have five petals, but in this particular species they form a wide, cupped flower.
How do you know if your area is suitable for cultivating a particular species of hibiscus? One simple way is to investigate what flourishes in nearby gardens. Many Japanese people love to talk about their garden and may pass on some tips.
Hibiscus flowering season is from July to October, after which come globose seed capsules 2.5 cm wide and containing many tiny hairy seeds. These germinate easily if sown fresh in the ground or in a pot with good seed compost.
One variety of confederate rose has white flowers that, as the day progresses, change to red. Known as sui-fuyo in Japanese (H. mutabilis “Versicolor”), the freestanding shrubs can grow to 2-3 meters. The flowering season, however, is short: August to September. The plant’s red-and-white coloration and its Japanese colloquial name — which literally translates as “not using water” (a reference to its drought-tolerance) — is jokingly said to allude to heavy drinkers, who are white-faced when sober and then flush red when they are intoxicated. Sui-fuyo has 20-25 petals and makes an attractive garden plant. One of my favorite hibiscus is the common rose mallow, or perennial hibiscus, known as amerika-fuyo in Japanese (H. moscheutos); its glory is the size of its flowers, and in tropical areas there are estimated to be some 120 cultivars. Native to North America, this is one of two perennial species of hibiscus. In nature, the plant’s height is 2 meters, but potted plants are around 1 meter — perfect for a sunny balcony. Flowers bloom from July through to September.
One cultivar known as southern belle has pale peach-colored flowers, each up to 30 cm wide. Golden stamens are clearly visible in the center of the flower, with three female stigmas at the top of the stamen tube. Individual flowers last for only one day, but the plant can continue blooming for 40-50 consecutive days. Heights for this species vary from 50-70 cm for the smallest to 1-1.8 meters for the tallest. Propagation is by dividing the plant in early spring.
The second perennial species of hibiscus is H. coccineus, native to Florida. The common English name is scarlet rose mallow, and in Japanese it is known as momiji-aoi. The leaf does indeed look like a large cut-leafed Japanese maple, with 3-7 toothed-edged lobes. Like the common rose mallow, the flowers on this plant only last for one day. In Japanese they are known as ichi-nichi-bana (one-day-flowers). Flowers are anemophilous (fubaika in Japanese), meaning they are wind-pollinated. The scarlet rose mallow was introduced to Japan sometime during the early Meiji Era (1868-1912) and, though not a native plant, is popularly used in traditional Japanese gardens.
The hibiscus you see when you visit tropical regions is most likely the Hawaiian hibiscus (H. rosa-chinensis), known in Japan simply as haibisukasu. Other common names — shoe flower and shoe black — originate from a traditional usage of the mucilaginous (slimy or composed of mucilage) petals to polish shoes. In India, these flowers are still used for the purpose. This hibiscus is unknown in the wild and is possibly an ancient hybrid of several other species of hibiscus. Although its origin is unclear, it is certainly not native to its most celebrated home, Hawaii. The Hawaiian hibiscus is important in Hindu devotional ceremonies, being sacred to Ganesh, the elephant god. A dense evergreen shrub (1.5-3 meters high), its flowers are as short-lived as those of other hibiscus species. Flowers are 7-10 cm wide; colors range from white to pink to red, yellow, apricot and orange. There are estimated to be more than 250 cultivars. H. rosa-sinensis “Cooperi” is an old cultivar whose narrow leaves are white-pink variegated. The Hawaiian hibiscus requires regular fertilizer, and plants must have excellent drainage. Potted plants should be fertilized every fortnight between April and September, and in Japan can be brought outside during the summer months.
A popular newcomer in this country is a hibiscus known as kenaf in both Japanese and English (H. cannabinus). Native to tropical Africa, this hibiscus is an annual and is generally cultivated not so much for its small yellow flowers but for fiber. Its other common names include ambari, Deccan hemp and Bimlipatum jute. Long cultivated in China, India and Southeast Europe, the 2- to 4-meter-high stems produce a jute-like fiber, and oil from the seed is also traditionally burned for illumination in some parts of Africa. Easy to grow from seed, kenaf is now cultivated throughout Japan, and paper made from it is manufactured in Hiroshima. I was recently in a restaurant where I noticed the paper mats were made from kenaf: a small step in the right direction toward protecting native forests around the world.