By Bodie V. Pennisi
University of Georgia
Growers and landscapers are becoming more savvy, too, in catering to this spirit of landscape adventure. We're now seeing large, bold leaves and tropical textures in most garden settings. Flowers are taking a step back, leaving us to focus on the foliage instead and to explore variations such as texture and color.
At the University of Georgia in Griffin, we're continuing our quest to investigate the landscape performance of new tropical species and cultivars. We're raising the public awareness, too, of the alternative uses of tropical plants in the landscape.
We're also evaluating plant hardiness in our area, in U.S. Department of Agriculture hardiness zone 7b (with minimum temperature averages of 5 to 10 degrees Fahrenheit).
Full sun or partial shadeHere are some winners from our garden. These are all great as tall background or specimen plants and have been hardy in Griffin for the past three years. They grow best in full sun or in morning and afternoon shade with midday sun.
Alocasia 'Williams hybrid' grows 42-44 inches high, with medium green foliage undulated with prominent veins and flowers through the summer. The stems grow thicker in full sun. This is a very strong performer with impressive landscape impact.
Colocasia nancyana grows 36-40 inches tall. Its green foliage has a creamy yellow, variegated center and veins. It has strong growth with good impact. Its stems grow thicker and it suckers more (produces more offshoots) in full sun.
Colocasia esculenta 'Red Stem' grows 34-38 inches tall with medium green leaves with reddish petioles. It's a strong plant with good impact with its attractive red leaf petioles. It, too, has increased stem thickness and suckering in full sun.
Curcuma 'Aussie Plume' and 'Giant Plume' grow 34-38 inches tall with medium green leaves. It has bright pink bracts and yellow flowers, too, throughout the summer and fall. It's a vigorous performer with strong landscape impact. And it's great for cut flowers.
Curcuma 'Emperor' grows 36-40 inches tall with medium green leaves with white margins. It produces white flowers throughout summer and fall. A strong performer, it has excellent landscape impact and is also great for cut flowers.
Plants for full shadeHere are some species more suitable for full shade:
Cornukaempferia 'Jungle Gold' is best used as a groundcover or mass planting. It grows 6-8 inches tall with round, velvety leaves with silver spots on a dark background. With orange flowers, too, it makes an impressive impact in the landscape and is a strong performer.
Kaempferia 'Alva' grows 6-8 inches tall, too, and is also best as a groundcover or in a mass planting. Its leaves are oval, medium green with brown spots. Another strong performer, its pale lavender flowers add to its landscape impact all season long.
Kaempferia 'Grande' grows 16-20 inches tall and is best used as specimen plants or in mass plantings. Its oval, silver-spotted leaves grow on long petioles and make an impressive landscape impact. It's a strong performer.
Kaempferia pulchra 'Raven' grows 18-24 inches tall and is best used much as Kaempferia 'Grande' is. It doesn't have flowers, but its lance-shaped purple and silver-spotted leaves on long petioles produce an impressive landscape impact. It performs well in the landscape.
(Bodie Pennisi is a Cooperative Extension floriculture specialist with the University of Georgia College of Agricultural and Environmental Sciences.)