Long summer days are required to get many plants to flower, especially when it comes to the family of gingers. We often take for granted that which we have in abundance. When we are in good health, we sometimes don’t appreciate it until we get sick.
The same holds true when it comes to our amazing gardens. Hawaii is blessed with a vast array of flowers, and we use them in the landscape for many reasons. Colorful flowering plants add visual beauty. They are useful for leis and flower arrangements, but an added advantage is that many are fragrant. Moist humid tropical climates have the potential for rot and decay. This means bad smells, so by adding colorful and fragrant plants to the landscape, we can actually help to mask unwanted odors.
Gingers are among the easiest of plants to grow for this purpose. Many species have naturalized and we tend to think of them as weeds, but we should be considering that such plants give us beauty and have valuable uses as well.
Pharmaceutical companies have been studying the ginger family in recent years and found that many have medicinal qualities. Even the maligned Kahili Ginger has been found to have anti-cancer properties and has been used by earlier cultures for a variety of ailments. Edible ginger or Zingiber officinale, Turmeric or olena and Cardamom are spices but were originally used as medicines and have antioxidant properties.
The ginger used in Thai cooking is galanga and we must not forget the awapuhi kuahiwi or soap ginger that early Polynesians brought to Hawaii many centuries ago.
The ginger family is noted for its many colorful and fragrant species. Gingers are related to the banana, palm and bamboo families, in that they are monocots. Many come from Malaysia, Indonesia and other parts of Southeast Asia.
There are almost 50 genera and more than 1,300 species in the family, the majority of which are native to tropical regions of the eastern hemisphere. More are being discovered every year. Most genera are well adapted to Hawaii’s varied climate. Many grow in the tropical zone, but some will thrive at 6,000 or more feet of elevation.
Gingers are rhizomatous perennials, generally with simple unbranched above-ground stems. Flowers vary considerably, from small to very showy, and are usually borne in heads. Many of the ginger flowers are very fragrant, so fragrant in some cases that they are over-powering in a small room. Flowers and foliage of many species are excellent for use in floral arrangements.
Gingers are relatively easy to cultivate, and once established require little care. They grow well on a wide range of soil types, as long as the soil is moist at all times. Riverbanks and land adjacent to ponds or boggy spots are choice locations, and will support the best growth. If gingers are planted on high dry soils, frequent applications of water are necessary.
Handle gingers the same as bananas. They do best in moist soil high in organic matter. An application of fertilizer in early spring when growth begins, and two more applications at the same rate during the growing season will be sufficient. The fertilizer applications should be spaced eight weeks apart. Also, compost and well rotted manures applied every three months will help keep the soil sufficiently rich. Planting or transplanting can be done at any season of the year. The parent clump may be divided like any rhizomatous herb. The fleshy underground rhizome may be severed at any point, as long as each piece has at least one good eye to produce a new plant.
Here are some other gingers to consider for your garden. The torch ginger, red ginger and Tahitian red ginger are just a few that you will find at local nurseries. You will sometimes see a plant called Blue Ginger. It is attractive and easy to grow, but is not a ginger. It is dichorisandra thyrsifolia from Brazil and is related to wandering jew.
The butterfly lily, or white ginger, with its heads of white butterfly-like flowers is commonly found. The extremely fragrant flowers last but a day and are constantly being replenished by a new supply. The flowering period will last for several months. Although common in the wilds, this is still one of the best for garden fragrance and lei flowers. The yellow ginger or hedychium flavescens from India is another fragrant specie common in wet forests and along east Hawaii roadsides. There appear to be hybrids among species. Some are particularly attractive and excellent for long lasing flower arrangements. Work should be done to select better hybrids and name them much like we have with hibiscus, croton and plumeria.
The shell ginger with its 3 to 8 foot stalks of evergreen foliage is frequently used in sunny, drier conditions than most gingers. Its flowers, with their combination of cream, yellow, and red markings are excellent material for floral arrangements. Leaves are used to dye cloth and as a tea in Japan. Other gingers to consider are the Costus or spiral gingers. There are many species and varieties. The orange flowered Himalayan ginger, hedychium greenei is sometimes called the Guava Jelly Ginger. It is so cold hardy that it will winter over as far north as Seattle and Victoria, British Columbia if given a little protection. On the Hilo side, you will also see fields of edible ginger grown commercially.
We tend to take gingers for granted in Hawaii, where they grow so easily, but few plant materials give so much for so little work. Try several types if you have the room in your garden.
One caution to note is to remember that the Kahili ginger is one that seeds and spreads in the wet, higher elevations. Folks in the Volcano area are concerned that it is proliferating in the Volcanoes National Park. Since the National Park personnel are trying to keep non native plants out of the park, it would be helpful if the spent flower heads were removed from your garden Kahili ginger plants before they set seed. The seed may also be harvested for culinary and medicinal uses. Of course Park officials would probably prefer it if residents adjacent to the park avoided planting Kahili ginger altogether.
For answers to your questions about fragrant plants, call the UH Master Gardener Helpline at 322-4893 in Kona and 981-5199 in Hilo.