Tidewater Gardening - May 2012

Reblooming Shrubs

by

K. Marc Teffeau

With the unusually warm winter and early spring it seems like the flowering shrub display was all crammed into a period of a few weeks rather than the prolonged season of color we usually have. The nice aspect of the fairly mild winter is that there was no flower bud damage from the cold temperatures and the plants have come out in full flower display.
Spring flowering shrubs are a major part of the home landscape and it seems a shame that we cannot enjoy a longer color show. Some of the spring flowering shrubs have very nice bright fall foliage colors that provide another show, but many do not.
With the success of the Endless Summer™ reblooming hydrangea series introduction by Bailey’s Nurseries a couple of years ago, gardeners interest in remontant or reblooming shrubs has increased. As compared to the traditional big leaf hydrangea, which only blooms in the late spring on old (last year’s) wood, Endless Summer™ has been bred to bloom on both old and new wood.
Remontancy is a genetic characteristic that ornamental plant breeders are selecting more. It means the plant can bloom on old wood (buds set in the summer or fall of the prior year) and new wood (buds set during the current growing season). If you deadhead spent blooms your reblooming shrub will provide you with more blooms.
Some reblooming shrubs will have a time when they bloom profusely and then rebloom more sporadically over the course of the summer and early fall. If you are interested in adding reblooming shrubs to your landscape there are a number of plants now available to the gardening public.
Lilacs are a longtime garden favorite dating back to the mid-1700s when both Thomas Jefferson and George Washington grew them in their gardens. Lilacs are a traditional landscape shrub that blooms in late April and early May. There are a series of reblooming lilacs now that would be a great addition to the traditional ones.
“Josee” reblooming lilac is a dwarf lilac that can bloom until frost. This hardy lilac gives its best flowering in full sun, and at 4 to 6 feet tall and a spread of 4 to 5 feet, it can be used as an accent shrub or grouped as a hedgerow. Its fragrant lavender-pink panicles of trumpet-shaped flowers are 4 to 5 inches long and are attractive to butterflies.
If you want a purple lilac the Proven Winners breeders have introduced Bloomerang® Purple Syringa. This fragrant lilac blooms in the spring and then again throughout the summer. It does go through a rest period in the heat of the summer, and then flowers until frost. Its compact mounded form is ideal as a foundation planting or as part of the mixed border. You can even include it into perennial beds. As an added bonus it is resistant to deer feeding.
Bloomerang® grows between 4 and 6 feet in height with the same amount of spread. As with all lilacs, it requires well-drained soil and full sun. Flower production may decline during extremely hot summers but will resume when temperatures cool in the fall.
Azaleas provide an awesome color display in the spring. A whole new series of reblooming azaleas has been introduced by different plant breeders over the last couple of years. Another Proven Winners introduction is Bloom-A-Thon® Red Reblooming Azalea. Its large flowers appear in April, and then rebloom in early July, continuing through fall until hard frost. The evergreen foliage is disease resistant, and maintains excellent color year-round. Flowering lasts for 4 to 6 weeks in spring, and then another 12 to 16 weeks in summer and fall.
This azalea grows 3 feet by 3 feet and can be used as foundation plant. As with all azaleas Bloom-A-Thon® Red prefers light shade, adequate moisture, and fertile well-drained organic soil. Part sun to dappled shade is ideal and eliminates flower scorch in full summer sun. Prune to shape and fertilize after the first major spring bloom.
The Forever and Ever® Azaleas brand of reblooming azaleas from the Berry Family of Nurseries contains eight varieties; Flame Creeper, Red Slipper, Chinzan, Wakaebisu, Hardy Gardenia, Conversation Piece, Macrantha Orange and Macrantha Pink. The color range of this azalea group is from white to pink to red and orange.
One of the most popular selling of the reblooming azaleas has been the Encore® Azalea series. There are 25 varieties of Encore® Azaleas currently in the marketplace. A unique aspect of these plants is that, unlike traditional azaleas, Encore® Azaleas can tolerate full sun. The ideal planting environment should provide 4 to 6 hours of direct sunlight, with some shade during the afternoon heat.
Developed by plant breeder Robert E. “Buddy” Lee of Independence, La., the evergreen Encore® Azaleas enjoy more sun than traditional azaleas, but offer the same easy care. Lee first envisioned Encore® Azaleas in the early 1980s when he found a tray of azalea cuttings blooming in the summer sun at his small Louisiana azalea nursery. Inspired, he began crossing traditional spring-blooming azaleas with the rare Taiwanese summer-blooming azalea, Rhododendron oldhamii. Licensed by Plant Development Services, Inc out of Loxley, Alabama, Encore® Azaleas are grown by 22 different nursery crop producers all over the U.S.
When I was traveling in March to Atlanta, Georgia, I stopped by ANLA grower member McCorkle Nurseries in Dearing, near Augusta, Georgia, and spent the day with Skeetter McCorkle and his dad Don. McCorkle’s has its own series of reblooming azaleas, the Bloom ’N Again® Azalea, which were beginning to bloom out. The McCorkle’s have carefully selected these azaleas for their repeat blooming habit and cold hardiness.
Like the Encore® series the Bloom ’N Again® Azaleas are evergreen shrubs, good for planting in mass or integrated into a hedge or shrub border. With little need to prune, they are perfect for a naturalized area such as a shade or woodland garden. However, like traditional azaleas, the Bloom ’N Again® Azaleas prefer part shade and are generally cold hardy from -10° to 0° with showy blooms in spring and fall. Dependent on growing conditions, most of the Bloom ’N Again® Azaleas start their fall blooming season in late September.
Lest you think that the azaleas have the market cornered on reblooming, consider the ‘Summer Snowflake’ Viburnum. Known as Japanese snowball this deciduous shrub grows 3 to 5 feet tall by 3 to 5 feet wide. Its non-fragrant, creamy white flowers in small, flat-topped umbels (2 to 4” diameter) appear in a profuse spring bloom in May, with sporadic continued bloom occurring throughout the summer into September. Flower clusters appear in two rows or files, hence the common name of doublefile viburnum.
This viburnum will do well in full sun to part shade but will give the best flower display in the full sun. Another attractive characteristic is that it produces a showy fruit in the fall which attracts birds. In fact, its reddish to bronze-purple autumn foliage color, its white flowers and orangish-red, berry-like drupes which mature to black, may all be simultaneously present on plants in early fall.
This shrub is easily grown in average, medium, well-drained soil but tolerates a wide range of soils and has good drought tolerance. ‘Summer Snowflake’s’ ovate, dark green leaves are up to 5 inches long and give it a good background in front of which you can plant other smaller shrubs for good contrast.
So, if you want more shrub flower pizzazz in the landscape to extend beyond the usual spring flash, do some shopping at the nearest garden center and add a couple of the suggested “rebloomers” to your landscape.
Happy Gardening!