Summer means many fragrant flowers blooming in abundance. Most noticeable is the family of gingers. Gingers are coming into flower a little late in forests and gardens this year due to cool weather conditions in some areas of the island. Visitors to our islands frequently comment on how fragrant our air smells with the abundance of flowers in bloom. Kamaaina often take for granted that which we have in abundance. When we are in good health, we sometimes we 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 volcanic eruptions, rot and decay. This means bad smells, so by adding fragrant flowering plants to the landscape, we can actually help to mask unwanted odors.
Gingers are among the easiest plants to grow for this purpose. Many species have naturalized and we tend to think of them as common, 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 sometimes-maligned Kahili ginger, Hedychium gardnerianum 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 anti oxidant properties. The ginger used in Thai cooking is galangal 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 around 50 genera and over 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 climates. Many grow in the tropical zone, but some will thrive at 6,000 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 overpowering 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 3 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, shell ginger, white ginger, yellow 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 true 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 growing wild. 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-lasting 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 greenii sometimes called the Guava jelly ginger does best in cooler gardens. 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. Be cautious planting Kahili ginger. It can seed readily under the right conditions. Rhizomes of this ginger can be tenacious and difficult to remove once established. On the other hand it is well-suited to steep hillsides for reducing soil erosion.