July/August Blooming Plumleaf Azaleas

July/August Blooming Plumleaf Azalea

Plumleaf azalea (Rhododendron prunifolium) is a deciduous azalea that is native to  Georgia and Alabama mountains (USDA hardiness zones 6-9). It is one of the signature plants of Callaway Gardens in Pine Mountain, Georgia.

Their bright orange-red flowers surprise in late July into early Augusta and may last for 2 weeks or more. Compared to many other spring blooming native azaleas, flowers are not fragrant. Spring and summer foliage is medium-green and is mostly blemish-free.

Fall leaf color is also uneventful. Insect and disease problems are rare if the plant is properly sited. 

This 5-8 feet tall and wide shrub performs best in morning sunlight and shaded from the harsh afternoon summer sun. It thrives in well-drained, compost amended soil. Plumleaf azalea prospers in the calcareous clay soils found in the Appalachian region without pH correction.  Plant in full-day light shade in zones 7-9. Set the shrub into a shallow wide dug hole that has been generously amended with compost and/or peat.

Feed in early spring with a slow-release fertilizer such as Osmocote™ or Nutricote™. An alternative nutrition program is to use a water soluble product such as Miracle-Gro™ or Jack's™  in early spring and again in early summer. Maintain 2-3 inches of a pine-based mulch around the base of the shrub. Irrigate plant(s) the first 2 years of establishment.

Plumleaf azalea blooms on new current season's wood. Prune deciduous azaleas anytime after bloom to maintain a desired height and spread. Plumleaf azalea is primarily available at local native plant nurseries or is offered online.

Plumleaf azaleas are usually available from mail order companies on-line.

Chinese (Kousa) Dogwood Doesn't Like Extreme Heat

photo: leaf curl on kousa dogwood
Never forget the adage: "the right plant in the right location". In USDA hardiness zone 7 and warmer parts of zone 6-b, Chinese dogwood (Cornus kousa) does not cope with excessive summer heat well. A typical stress response is leaf curling. On more stressful droughty sites, leaf margins and centers will likely burn.

The young tree pictured above is planted along a suburban street, with a concrete sidewalk and street curb on two sides. Thick turf sod covers the ground beneath the tree, competing with the tree for available soil moisture and nutrients. On a hot 90°F day, this tree is likely to experience heat indices above 120°F.

Likely, the tree will survive, but not bloom dependably every spring. Leaf burning and curling reduce the tree’s ability to photosynthesize, resulting in less (or more) flower bud set. The tree will either flower poorly or bloom heavily in future springs, resulting in an alternate flowering cycle or "biennial bearing".

Kousa dogwood will handle full sun locations, provided heat and drought stresses are managed through timely irrigation. Currently, the University of Tennessee is evaluating several seedling kousa selections for better heat and drought tolerances here in the mid-South.