Flora Ann vitex is an improved pink-flowering variety. (Photo by Allen Owings) Variegated forms of callicarpa such as the Duet variety are making their way into nursery production. (Photo by Allen Owings) Parsley hawthorn berries are showy in the landscape. (Photo by Allen Owings)
News Release Distributed 10/11/13
By Allen Owings
LSU AgCenter horticulturist
HAMMOND, La. – The LSU AgCenter is increasing work at the Hammond Research Station to select and breed new ornamental plants for the state’s growing nursery and landscape industry.
This new effort is being led by horticulture professor Charles Johnson from the School of Plant, Environmental and Soil Sciences and Daniel Wells, a post doctoral researcher in horticulture at the Hammond Research Station.
Some of the plants currently being studied include potential new varieties of Vitex (chaste tree) and Crateagus (native hawthorn). Several species of each plant are being used in breeding, hybridization and selection work.
The genus Callicarpa includes plants such as American beautyberry, Chinese beautyberry and Mexican beautyberry as well as variegated forms, such as the Duet and Snow Storm varieties. A collection of currently available varieties is being established now, and they will be evaluated for landscape performance over the next three to five years. We plan to grow a large seedling population that may yield future selections.
The species and existing varieties of chaste tree for use in the breeding program in the research station gardens include seedlings and cultivars of V. agnus-castus, V. negundo, V. rotundifolia and V. trifolia. V. agnus-castus varieties include Shoal Creek, Flora Ann, Montrose Purple, Pink Sensation, Salina’s Pink, Abbeville Blue, Patton’s Pink, Carolina Blue and Lecompte. V. trifolia varieties include Purpurea and Variegata.
Chaste tree has excellent ornamental characteristics. Vitex agnus-castus is the most commonly grown species in Southern landscapes and includes award-winning plants, such as Shoal Creek. These trees are prominent bloomers, displaying large spikes for several months from late spring to early fall. Flower colors include white, pink and shades of lavender blue. Foliage color and fragrance can also vary. Breeding goals include a long flower-spiked white bloom and a compact, dwarf growth habit.
While we may know the genus Crateagus as our popular mayhaw trees, Crataegus marshallii (parsley hawthorn) and C. lacrimata (Pensacola hawthorn) have potential ornamental value and are generally not available in the nursery trade. Hawthorns are native trees with great potential for increased landscape use.
The parsley hawthorn has spring-occurring white flowers; showy, exfoliating bark; and unique foliage texture. Some flowers can have a pinkish look.
Pensacola hawthorn is native to Florida and southern Alabama and displays a weeping form with attractive ridged and furrowed bark. White flowers appear in spring and are followed by red fruits that persist into summer. It would be great to select a reliably dark pink flower form with weeping characteristics and eye-catching fall foliage color.
All of these plants have an additional purpose – they attract wildlife.
The beautyberry seeds and berries are highly favored by birds such as bobwhite quail, and foliage is favored for browsing by deer.
Hawthorns support bumblebees and provide roosting locations for robins and blackbirds, basking spots for butterflies and habitat for small mammals.
Chaste trees attract beneficial insects (including bees), provide bird habitats and are a nectar plant for many species of butterflies.
The new ornamental plant breeding and selection effort at the Hammond Research Station complements other programs here. Some focus on plant trials and evaluations for retail garden centers and the landscape and nursery industry. Others concentrate on researching best management practices and cultural recommendations to grow better trees, shrubs, bedding plants and herbaceous perennials for Louisiana.
You can see more about work being done in landscape horticulture by visiting the LSU AgCenter Hammond Research Station website. Also, like us on Facebook. You can find an abundance of landscape information for both home gardeners and industry professionals at both sites.
Rick Bogren