(06/09/16) HAMMOND, La. – Japanese maples can be outstanding small trees for specimen plantings and focal-point use in residential landscapes in the Southeast. An LSU AgCenter expert says more home gardeners and landscapers are planting Japanese maples in Louisiana.
Variations in leaf color and shape are unique horticultural characteristics of Japanese maples, said LSU AgCenter horticulturist Allen Owings. Some of the finer-textured-foliage species are referred to as threadleaf forms.
“You can find green-foliaged and red-foliaged varieties,” Owings said. Most of the green-foliage varieties turn reddish or yellow in fall. Red-foliage varieties are most susceptible to sun scald during summer and early fall.
Japanese maples have a slow growth rate, and most varieties will mature to a height of about 15 to 20 feet with an average width of 10 to 15 feet. Dwarf types also are available.
Spreading forms grow wider than tall, and some varieties have a cascading, umbrella-shaped canopy, Owings said.
Normally, Japanese maples do best in USDA hardiness zones 5 to 8. “Louisiana is in zones 8 and 9, so being located in the southern edge of the recommended planting region can present some challenges,” Owings said.
With proper planting and site selection, however, Japanese maples will do well in Louisiana, he said.
Japanese maples should be planted in partial-sun-to-partial-shade locations for best results. “Full sun will result in leaf burn on many varieties during summer,” Owings said.
A little more sun than shade, however, will result in enhanced leaf color.
Because leaf scorch can be a problem by midsummer to early fall on many varieties, Owings recommends locations with reduced sun exposure in afternoons.
Planting should be in slightly acid, well-drained soil, Owings said. Mulch with pine straw to protect the shallow root system from excessive drying out and irrigate only as needed.
Once established, Japanese maples need little care. “Just prune them lightly in winter as needed the first five years to maintain the desired shape and to remove competing branches,” he said. And apply light applications of a slow-release fertilizer every couple years in early spring.
The many varieties of Japanese maples, including Bloodgood, Fireglow, Crimson Queen and Burgundy Lace, are available at Louisiana garden centers, Owings said. Smaller varieties are appropriate for container planting.
The AgCenter has initiated a Japanese maple evaluation and collection program at the Hammond Research Station, Owings said. More than 125 varieties are currently planted with an additional 50 to 100 varieties planned for the next few years.
Highly variegated foliage of Kagiri Nishiki Japanese maples needs a shaded location in the landscape. Photo by Allen Owings
Japanese maple varieties thrive in the Piney Woods Garden at the LSU AgCenter Hammond Research Station. Photo by Allen Owings