By Dan Gill, LSU AgCenter Horticulturist
The third Friday in January is Arbor Day in Louisiana – a day we set aside to celebrate and appreciate the role living trees play in improving our lives and our environment. Many people plant trees to celebrate the occasion.
Spring-flowering trees will add so much color and beauty to our landscapes over the next few months, and now through early March is an excellent time to plant these and other types of trees in the landscape.
At 40 feet tall, the largest of the spring-flowering trees is our native swamp red maple (Acer rubrum var. drummondii), which is coming into bloom now. This tree species separates the sexes into individual plants, so there are male swamp red maple trees and female swamp red maple trees. But the females put on the more-attractive display in the spring. Not only are their flowers more showy, but they turn into attractive fruit. You may notice trees in your area that have deep red, burgundy or rusty red, boomerang-shaped fruit clustered all along their leafless branches.
The swamp red maple makes an excellent shade tree. Although it grows in swampy areas, it adapts readily to well-drained urban landscapes. It is a deciduous tree with an upright, oval shape and a moderate to fast rate of growth.
The Taiwan flowering cherry (Prunus campanulata) produces deep pink flowers in great abundance before the leaves emerge. Flowering generally begins in mid- to late January and extends over two to three weeks. This is one of the few flowering cherries that grows and blooms reliably this far south. They prefer to grow in a sunny to partly sunny location with excellent drainage. The Okame flowering cherry (Prunus x incamp Okame) is another type that will grow successfully in Louisiana. Ti produces pale pink flowers in March or April.
The Oriental magnolia (Magnolia x soulangiana) is one of the most spectacular of the spring-flowering trees because its flowers are so large. Unlike the evergreen Southern magnolia, the Oriental magnolia is deciduous and loses its leaves in winter. Appearing before the foliage in January and February, the fragrant flowers are tulip-shaped, 4 to 6 inches across, and may be flushed pale pink to purple on the outside and white on the inside. Long-lived and reliable, Oriental magnolias grow 15 to 20 feet tall and need a sunny location with good drainage.
The related star magnolia (Magnolia stellata) is smaller, growing 10 to 12 feet tall, and is more shrub-like. The white or pale pink flowers are star shaped and wonderfully fragrant. Blooming in late January or February before the foliage emerges, the star magnolia is an excellent choice for small-space gardens.
The native silver bell (Halesia diptera) is a lovely tree often recommended as a substitute for dogwoods and is less fussy about its growing conditions. The silver bell and dogwood donít really resemble each other that closely, but the silver bell blooms at about the same time with small, four-petaled, white flowers that hang down from the branches in large numbers. The thin leaves allow light to filter through, creating a lovely effect under the tree. They grow well with light shade or full sun and mature at about 25 to 30 feet.
The hawthorns are a wonderful group of native trees that provide spring bloom as well as fruit for human or wildlife consumption. One of my favorites is the parsley hawthorn (Crataegus marshallii). Growing 15 to 20 feet tall, it is an excellent choice in patio or small-space plantings.
The clusters of white flowers appear in March or April and are soon followed by the foliage, which looks like flat Italian parsley, hence the treeís name. The small red fruit that ripen in fall are relished by mockingbirds. Parsley hawthorn is tolerant of poorly drained soils and grows in full sun to part shade. When the trees are young, they have thorns.
Fringe tree (Chionanthus virginicus) is a delightful native tree that thrives in well-drained locations with full sun to partial shade. The flowers are greenish white and are produced in masses all along the branches. The narrow petals and hanging habit give the flowers a fringe or beard-like appearance. In the wild you usually see them growing on the edge of the woods. The Chinese fringe tree (Chionanthus retusus) also grows well here and is even showier than our native species.
Another excellent spring-flowering tree is the redbud (Cercis canadensis), which usually blooms in late February or March. Small, pinkish-purple, pea-like flowers are produced in unbelievable profusion along the branches (and even on the trunk!) before the leaves appear. This habit of blooming before the leaves grow out is fairly common among the spring-flowering trees and really adds to the impact of the flowers. Redbuds are relatively fast growing once established and prefer full sun and a well drained location.
Finally, thereís a tree you are not likely familiar with and you are not likely to find in area nurseries. But itís a really wonderful and much underused tree for Louisiana landscapes. Iím talking about the Japanese apricot (Prunus mume). It produces single or double 1-inch flowers in shades of red, pink and white in great profusion in late winter or early spring.