Sunday, May 30, 2010
Locate a site with a “micro-climate" advantage such as next to a driveway or along the southside of a red brick home or a dark colored garage wall. Here winter temperatures vary by a few degrees warmer. Dark asphalt pavement absorbs and retains heat. Next to large bodies of water, such as a swimming pool and a water garden, may also be slightly warmer in the winter.
Plant rosemary in well-drained soil and in full direct sunlight. With rosemary and other semi-tender herbs, winter kill may also be caused by wet, soggy soil rather than cold.
‘Arp’ matures a handsome woody shrub with fine textured foliage. It grows 3-4 feet tall and wide, and blooms in early spring. The blue flowers are small and attract lots of insect activity.
Monday, May 24, 2010
Multi-flora roses, a noxious shrubby weed, are most susceptible and often are first to contract the disease. Very small eriophyid mites transmit rose rosette disease by feeding off the plants which are already infected. Mites transmit the virus to healthy roses nearby. Control measures must be rapid and decisive.
Insect spraying will help. Spray roses with Sevin (carbaryl) insecticide for partial control of the eriophyid mite. Eliminate multi-floral roses within 300 feet from any rose plantings, preferably from all surrounding yards and gardens.
Prune out all diseased and suspected canes. Remove all prunings immediately from the property. If symptoms reappear on new re-growth canes, remove the bush from the property. When planting roses, space them far enough apart that foliage does not touch neighboring plants.
Saturday, May 22, 2010
There are two kinds of lavender. The shorter-growing cultivars of English lavender (Lavandula angustifolia) like ‘Munstead’, ‘Hidcote’, and ‘Lady Lavender’, flower in mid-May for one month. When cutback, English lavender blooms again in August. The taller more vigorous French lavender (recommend cultivars ‘Provenance’, ‘Grosso’ and ‘Super’) flowers only once in late June. For lavender oil production, I recommend ‘Super’.
Thursday, May 20, 2010
Monday, May 17, 2010
Photo: Carefree Sunshine Rose at UT Gardens in Knoxville, TN
Over the past decade the Knockout®, Carefree® and Home Run® series of shrub roses have altered the appearance of residential and commercial properties. From 2006 -08, no-spray rose trial was conducted at two University of Tennessee Research and Education Centers in Jackson and Crossville, TN and the USDA Horticultural Research Lab in Poplar, MS.
Over 135 cultivars were evaluated. "The ultimate disease test for roses is to test them south of the Mason-Dixon line where disease pressure is highest", according to Dr. Mark Windham, UT Research Pathologist.
Carefree Sunshine (MR) - F
‘Golden Eye’ (R]
‘Hansa’ (R) - F
Knockout Rose (R)
‘My Girl’ (R) - F
‘My Hero’ (MR)
‘Palmengarten Frankfurt’ (MR) - F
Pink Knockout (R)
‘Super Hero’ (MR)
’Wild Spice’ (MR) - F
‘Wild Thing’ (MR)
‘Wildberry Breeze’ (R) - F
F indicates rose is fragrant
Saturday, May 15, 2010
Since its introduction in the rose world over 60 years ago, 'White Dawn' has proven to be a top garden performer among climbing roses. The dark green, glossy foliage is very blackspot disease resistant. This very vigorous climber (hardiness zone 5 – 9) grows to 12 to 20 feet. Pure white double flowers are medium-sized (2-1/2" to 3"). 'White Dawn' tolerates poor soils if drainage is good. It blooms best in a bright sunny spot.
'White Dawn begins blooming in mid-May in the southern Appalachian region (Zone 6-b to 7-a) and repeats, off and on, through the rest of the growing year. Feed roses starting in early April and monthly to early September with Miracle-Gro®, Schultz®, or equivalent water soluble rose food @ 1 tablespoon per gallon.
Prune climbing roses in late winter (March) when new growth begins. On young climbers, simply remove all diseased, dead and tall nuisance canes. On older climbers, cutback the oldest rambling canes, favoring strong healthy one-year shoots which produce most of the rose blooms in May.
‘White Dawn’ is the first climbing rose to earn the University of Tennessee “No Spray” designation.
Friday, May 14, 2010
American yellowwood (Cladrastis kentukea) is a medium-sized flowering landscape tree. Generally, from early to late May, the beautiful yellowwood tree blooms in the Southern Appalachian region (USDA zone 6-b to 7-a). Twelve to fourteen inch long white pea-shaped flower panicles drape from the tips of tree branches.
I know the location of a dozen yellowwood trees in northeastern TN and 11 of 12 did not bloom in 2009. The 12th tree bloomed sparsely. In 2010 all trees are exceptionally beautiful in full bloom this week and last. So far, plant scientists are at a loss predicting the “on” and “off” annual flowering pattern.
Yellowwood may bloom 2 to 3 consecutive years and not flower again for the 1-2 years. A complex of environmental and physiological factors may be involved. The weather history over the past decade in the Southern Appalachian region has included several abnormally hot, dry summers and mild winter temps. The 2009 summer was unusually cool and moist followed by a longer cold winter.
A second theory, called "biennial bearing", states that if a tree sets an unusually heavy seed load in the summer, few to no flowers are initiated for the following spring.
The flowering trigger for yellowwood tree is not understood. Whether in flower or not, yellowwood makes a fine addition to any landscape.
Monday, May 10, 2010
Here are some good varieties to try. The yield will vary with the variety:
– Bush Early Girl
– Bushsteak Hybrid
– Spring Giant
– Better Boy
– Bush Celebrity
– Mountain Fresh Plus VFFN
– Super Bush
– Saladette (Roma type)
– Golden Nugget
– Sweet 100 Patio
– Tiny Tim
– Supersweet 100
– Sun Gold
Friday, May 7, 2010
Those of us who live north of Atlanta, GA (USDA zone 7-b) can not enjoy Italian cypress (Cupressus sempervirens), which are not hardy in most of the Southern Appalachian region (zone 6-a to 7-a). If you are designing a Mediterranean look in your garden, choose among select cultivars of these columnar evergreen shrubs:
Japanese holly (Ilex crenata) 'Sky Pencil'
Upright boxwood (Buxus sempervirens) 'Dee Runk' and 'Pyramidalis'
Red cedar (Juniperus virginiana) 'Taylor', 'Brodie', 'Blue Arrow', 'Idyllwild'
Alaskan cedar (Chamaecyparis nootkatensis) 'Green Arrow', 'Van den Akker'
Wednesday, May 5, 2010
Monday, May 3, 2010
The bright reds, oranges and yellows of the hybrid deciduous azaleas (Rhododendron spp.) are lovely among tall shade trees which protect them from the harsh afternoon sunlight of summer. Because their bloodline is from our native piedmont azalea species in the Eastern U.S., hybrid deciduous cultivars possess exceptional disease and insect resistance rarely seen in the more popular evergreen forms.
This past weekend I saw this lemon yellow gem (pictured) in a friend's garden in Lenoir, NC called 'Sunny Side Up'. The very popular 'Gibraltar' (bright orange) has been blooming over the past 15 years blooming in my northeast TN garden next to 'Gold Finch' (yellow-gold).
Annual care is very minimal: Feed once after flowering with any slow release azalea or evergreen fertilizer. To invigorate the azalea, prune back one or two very tall woody branches near the base of the shrub to promote new shoot growth. The new branches will likely flower next spring and many more thereafter. One year established shrubs are also very drought tolerant.