Tidewater Gardening - February 2007

Catmints and Dogwoods

by

K. Marc Teffeau

   Looking for a new perennial to add to your perennial bed this spring? The Perennial Plant Association has named Nepeta ‘Walker’s Low’ as the Perennial Plant of the Year for 2007.
    Nepeta (Nep-et-a) are commonly known as Catmints, not to be confused with Catnip. These perennials prefer a well drained, neutral pH soil in full sun or part shade. The dark blue flowers are produced prolifically starting in early summer. The flowering period can be extended by severely cutting back plants after the first flush of bloom.
    Nepeta ‘Walker’s Low’ is the newest addition to the list of hybrid Catmint cultivars. Its blue-violet flowers will bloom continuously throughout the season if properly pruned. ‘Walker’s Low’ growth pattern is lower and tighter than other varieties of Catmint and it does not require trimming as often as other cultivars might. It also has the characteristics of ease of propagation and is great for attracting bees, butterflies and other pollinating insects.
    This Nepeta is also free of pest and disease problems. It can be used effectively in the landscape as a companion for early and late blooming plants. It’s great for perennial borders, but can be used in herb gardens, rock gardens, as a ground cover, or as a container plant.
    Being a Catmint, its leaves release a wonderful aroma when crushed and, although related to true catnip (N. cataria), it has little attraction to cats (nor to deer or rabbits). The leaves do contain the feline attractant nepetalactone.
    The original hybrid species of Nepeta is named for Dutch nurseryman J. H. Faassen who developed the first hybrids of this genus. The ‘Walker’s Low’ cultivar, which was introduced by Four Seasons Nursery of Norwich, England, in 1988, was first found in an Irish garden in the 1970s by Mrs. Patricia Taylor and named for a garden there.
    Speaking of award winning plants, the Pennsylvania Horticulture Society has announced its selections for the 2007 Gold Medal Plant Award Winners program. And the award winners are – hand me the envelope, please – a Dogwood, a Crepe Myrtle and a Staghorn Sumac.
    Let’s start with the first winner – Cornus Venus™ (Hybrid Dogwood). This gold medal winner is an improved dogwood hybrid with superb resistance to anthracnose and powdery mildew.
    It came out of Dr. Elwin Orton’s shrub breeding program at Rutgers University where it is a cross between C. kousa x nuttalli (the Pacific Dogwood) and part C. kousa. Cornus Venus™ has clean foliage and , being a hybrid, has a fast-growing, low-branching habit. In May this dogwood flowers out with 6-inch, big-as-your-hand, pure white blooms with green centers.
    At maturity, its size is projected to be 25 feet high by 25 feet wide in full or part sun. Given its potential to grow rather large, this is a shrub that needs plenty of room in the landscape. It would be excellent in a long shrub border.
    This dogwood does not follow the traditional growth habit of dogwoods. Instead of sending up a bare trunk, it is branched low to the ground and has a rounded, symmetrical outline. In the fall, Cornus Venus™ adds to the fall color display with its orange-colored leaves.
    The next 2007 PHS Gold Medal Plant Award Winner is a crepe myrtle, ‘Whit III’ Pink Velour®. This crepe myrtle cultivar, developed by Dr. Carl Whitcomb of Stillwater, Oklahoma, is a multi-stemmed shrub or small tree, reaching a height of 10 feet or more. Being deciduous, its new thick leathery leaves come out in late spring and are wine/burgundy in color. They eventually turn to a dark purplish green. The fall color is orange/brown. The summer flower display of ‘Whit III’ Pink Velour® is spectacular with flashy magenta-pink flower clusters.
    This cultivar is very drought tolerant and is cold hardy to -5 to -8° F. If the top is killed by cold, which can be a problem with some cultivars of crepe myrtle in our area, the regrowth is vigorous.
    Another added advantage to ‘Whit III’ Pink Velour® is that it is resistant to powdery mildew, eliminating the need to spray a fungicide on the plant to control this disease. Planting suggestions include using it as a specimen plant or near the foundation. You can prune the plant in late August or early spring. At maturity the plant is 10 feet high by 6 feet wide.
    The third PHS Gold Medal Plant Award Winner, Rhus typhia ‘Bailtiger’ Tiger Eyes® (Staghorn Sumac) is a cultivar of a native plant. As compared to the native Staghorn sumac, which can grow over 20 feet high, Tiger Eyes® stays at around six feet.
    A hybrid introduction from Bailey’s Nurseries in Minnesota, Tiger Eyes® has unique, purplish-pink stems displaying exotic cut-leaf foliage. Changing with each season, Tiger Eyes® starts out chartreuse in spring, turns bright yellow in summer, and blazes scarlet-orange in the fall.
    Native sumacs tend to expand by suckering and are considered somewhat invasive in the landscape. Tiger Eyes® is more compact that the native species and is not considered invasive.
    Great for use as a foundation plant, as a specimen plant, in mass in a large shrub border, or in a container, Tiger Eyes® is easy to grow. Grown in full or part-sun sites, this plant prefers well-drained soil but adapts well to poorer soils and urban situations and exhibits good pollution tolerance.
    While we are on the subject of shrubs, February is a great month to force shrub blooms for an early spring effect. Try forcing branches of some of these shrubs during the drab days of late February. You have a number of woody plants to choose from. Winter honeysuckle produces fragrant, white flowers. Fragrant viburnum has aromatic pink-to-white flowers. Japanese andromeda has white, urn-shaped flowers in sprays like lily-of-the-valley. Mountain andromeda has white flowers in upright open panicles. Buds of native trees such as dogwood, spicebrush, serviceberry and redbud will blossom indoors, as will azalea, rhododendron and mountain laurel.
    For something unique to force for winter flower arrangements, consider red maple, buckeye, birch, hickory, larch or oak branches. They will soon unfurl either flowers, foliage, catkins or red leaves that change gradually to green. If your yard has none of these, try a few branches of similar trees.
    Happy gardening!!!