They are tropical and subtropical plants that have beautiful and brightly coloured flowers from the order zingiberales. The ICAR-Indian Institute of Spices Research (IISR), Kozhikode has a rich collection of important ornamental gingers in its conservatory. These species also serve as the secondary gene pool for disease resistance and secondary metabolites to cultivated ginger and turmeric. Besides being colourful they are versatile and downright beautiful. They are the perfect no fuss addition to any tropical or subtropical garden.
The ginger family or Zingiberaceae is a family of flowering plants made up of about 50 genera with a total of about 1600 known species of aromatic perennial herbs with creeping horizontal or tuberous rhizomes distributed throughout tropical Africa, Asia, and the Americas.
Most ornamental gingers will flower for about 5 to 6 months and hence, they are of great value in the garden. They thrive in warm, humid, frost-free coastal areas as they are not tolerant to frost. Due care needs to be given during early stages of planting and establishment. Some varieties of ginger have fragrant flowers and others have spicy foliage. The Hedychiums (butterfly gingers) and some species of Costus are the most fragrant types of ginger. There are mainly two types of gingers based on their growth habit viz., evergreen and non-evergreen species. The former is green throughout the year and can be grown outdoors in summer and as houseplants in winter. The second group of plants completely dries off at the end of summer and after dormancy period it start growing again.
Shell ginger (Alpinia):
Alpinias are the largest genus in the ginger family with 250 species ranging from 12 to 25 cm as a general rule. This group of plants has major landscape value due to the different forms, varying heights, and their tropical foliage. Flowers are brightly and beautifully coloured. Some species are decorative for its variegated foliage ie Alpinia zerumbet (variegated), A. luteocarpa and A. sanderae.
Spiral gingers (Costus)
They are called spiral gingers because of their spirally arranged leaves. They are very diverse group of gingers, from sun lovers to shade lovers, ranging in height from 8 to 20 cm. They produce creepy flowers out of terminal cones while others produce plastic-looking tubes out of terminal cones (Costus erythrophyllus; C. malortieanus). The cones are very attractive even after they have finished blooming. Flowers are non-fragrant, but long lasting. Some species are decorative for its variegated foliage like Costus speciosus (variegated).
Hidden gingers (Curcumas)
Curcumas are valuable ornamentals for their beautiful spikes. The spikes are producied basally or from the central part of the plant. Some of the spring blooming Curcumas are very beautiful for its flower before the foliage has a chance to come up and hide them, hence the name “hidden ginger”. Curcumas that bloom out of the top are being used extensively in the cut flower industry (Curcuma alismatifolia, C. petiolata). They have to be protected from the hot, afternoon summer sun. This plant goes dormant within a week of consistent night temperatures of 400C.
Dancing ladies (Globba)
The Globbas are small plants that reach 30 to 60 cm. They prefer to grow in shady areas and produce beautiful brightly coloured flowers (Globba winitii), which looks similar to a dancing girl. Globbas require morning or filtered sunlight but direct light causes leaf scorching. Well-drained soil, keeps the rhizomes from rotting in the winter while they are dormant.
Butterfly gingers (Hedychium)
These are the most beautiful sweet scented gingers in the family Zingiberaceae, the individual flowers resembling butterflies. This group reaches a height of 15-20 cm in medium sun and 10 cm in full sun. India is the center of origin of this group with maximum number of species diversity in North- Eastern India. Hedychium coronarium, is widely cultivated, H. flavescens, H. greenii, H. rubrum, H. coccineum, H. wardii, H. elwesii, etc., are some of the beautiful butterfly gingers.
Peacock ginger (Kaempferia)
The Peacock gingers are also shade-loving plants. They have beautifully zoned patterns with silvers, blues, blacks, and shades of green make this plant very effective even without flowers. Iridescent purple flowers are produced over the top of the plants. If this plant receives too much sun, the leaves will curl up in defense against the hot rays, so they are planted in dark shady places.
Zingiber spectabile is native to Southeast Asia. It is primarily grown in the West as an ornamental plant, although it has been used in South-East Asia as a medicinal herb. The plant is commonly known as "beehive ginger", due to its unusual inflorescences which resemble a beehive. It is also referred as "Ginger wort" or "Malaysian ginger". The Z. zerumbet inflorescence which resemble a compact cone, emerge from the base of the plants and start with green color changing to red with age.
Gingers grows well in warm humid climate and is cultivated from sea level to an altitude of 1500 m above sea level. These plants are grown in full shade to under 90% sunlight. Varieties of ginger that need less sun are the Globbas (known as dancing ladies) and the Kaempferias (peacock gingers). Other similar plants are the Alpinias.
Ginger thrives best in well drained soils like sandy loam, clay loam, red loam or lateritic loam. A friable loam rich in humus is ideal. Proper nutrient management is required from September through to November to encourage flowering. The soil should be kept moist but not too wet for proper growth and development. A good layer of mulch will help keep the roots cool.
The propagation is very easy. Most of the species are propagated vegetatively by division of the rhizome and cuttings of the aerial shoot. Seeds also form an important planting material in the species of Alpinia, Curcuma, Hedychium, Costus etc. In A. purpurata the bulbils develop into seedlings before they are shed.
Most of the gingers are relatively pest and disease free. In heavy soils and water logged conditions, the most common disease of garden gingers include the soft rot or rhizome rot. Careful removal of the affected clumps and drenching the affected area with fungicides (Mancozeb, 0.3%) would check the spread of the disease. The mosaic or marble disease is another disease caused by a virus. Use of healthy and disease free rhizomes for planting and destruction of diseased clumps by burning are two effective methods of control.
Some of the important ornamental gingers are being collected and conserved in the field gene bank of the ICAR-Indian Institute of Spices Research (IISR), Kozhikode.
For further interaction, please write to:
Drs D Prasath, S Aarthi, VA Muhammed Nissar and J Rema, Scientists, ICAR-Indian Institute of Spices Research, Marikunnu PO, Kozhikode-673 012, Kerala, India
and Dr T Janakiram, ADG (Horticulture Science), Indian Council of Agriculture Research, New Delhi