Archive for the ‘Disease resistant’ Category

‘Cherokee Brave’– Outstanding “Red” Flowering Dogwood

Flowering dogwood (Cornus florida) is the most beautiful of U.S. native flowering trees (USDA hardiness zones 5 to 9). It typically grows 15-30 feet tall, but larger forms are known. The tree is broadly-pyramidal at a young age, branching is low, and matures with a rounded canopy. Spring bloom time usually overlaps with redbud (Cercis […]

Better Disease Resistance With Mountain Tomato Series

  Tomatoes are attacked by several diseases and insects. Most serious diseases are early blight, spotted wilt virus (TSWV), fusarium wilt (FW), Stemphylium Gray Leaf Spot (St), Alternaria leaf spot (A), and root knot nematodes (N). Major insect problems are aphids, thrips, stink bugs, blister beetles, fruit worms, horn worms, leaf miners, fruit flies, and […]

Mt. Cuba Center Evaluates Heuchera (Coralbells) Cultivars

              Over the past quarter century, gardeners have enjoyed the wonderful heuchera revolution (USDA hardiness zones 4-9). A great many hybrid cultivars have been introduced with more arriving every spring. Unfortunately, the flood of new cultivars has given us a huge number of poor selections. As I talk with […]

Blue Atlas Cedar Becoming Very Popular In Urban Landscape

Blue Atlas cedar (Cedrus atlantica ) hails from the Atlas Mountains in northern Morocco and Algeria (USDA hardiness zone 6). The cultivar ‘Glauca’ has been the popular choice because of its blue green foliage. Blue Atlas grows to 40-60 feet in height, but individuals over 70 feet are hard to find. Mature forms, those 50 […]

New Christmas Roses (Hellebores) Greatly Improved

  Christmas roses (Helleborus niger) is a winter flowering perennial. It is native to central and southern Europe (USDA hardiness zones 4-8) and is not as winter hardy as lenten rose (Helleborus x orientalis). Christmas rose tends to flower 1 to 4 weeks earlier, around the Christmas holidays in southern climes (zones 7-8). New selections of H. niger are better […]

List of Zone 6 Hardy Camellias Grows Longer

                If you live and garden in USDA hardiness zone 6, several camellia cultivars are winter hardy. The past decade has seen an increase in the list of hardy cultivars. These same cultivars are also reliable planted in zone 7. Here is a sampling of the best Zone […]

Tips On Crape Myrtles In Fall And Winter

                  Hardy cultivars of crape myrtles are best left alone in the fall. Light pruning to remove a broken branch or the seed capsules is ok, but major pruning should wait until early spring.  “Crape murder” is a common practice in the Southeast U.S. and is not recommended any time or place. It involves lopping […]

Better Choices Than Leyland Cypress For Privacy Screen

For homeowners in a rush to establish a tall green privacy screen from the neighbor(s), perhaps a 12-foot tall green fence may be your better option. Among the choices of evergreens to plant, Leyland cypress (x Cupressocyperus leylandii) is fastest growing, but is plagued by any of three serious disease problems. An established leyland cypress planted 12 feet apart completely […]

‘Gyokuryu’ Japanese Cedar -Privacy Screen For Small Gardens

Gyokuryu Japanese cedar (Cryptomeria japonica ‘Gyokuryu’) is a dense, broadly pyramidal evergreen shrub (USDA hardiness zones 5-8). It has short stiff needles that tend to be a slightly darker green than other cryptomeria cultivars. Gyokuryu holds its dark green color through most winters in zone 7 and further south. Expect winter bronzing when Gyokuryu is […]

Bee Bee Tree (Tetradium) Rarely Seen In U.S. Landscapes

                  Native to Korea and southwestern China, bee bee tree (Tetradium daniellii) is a deciduous tree with a spreading umbrella-shaped habit and rounded canopy (USDA hardiness zones 4-8). It was formerly named Evodia daniellii. Bee bee tree typically grows to 25-30 feet tall and wide. In July-August small […]