Old Glory (top) and Declaration lilac
Images courtesy U.S. National Arboretum.
Two New Lilacs From the U.S. National
Arboretum By Alfredo Flores May 2, 2006
Two of the newest additions to an ever-growing list of original
ornamental plants produced by breeders with the U.S. National Arboretum (USNA),
Washington, D.C., are lilac cultivars named Old Glory and
Declaration. They were recently released to the public by the
arboretum, administered by the Agricultural Research Service (ARS), the U.S. Department of Agricultures chief
scientific research agency.
The 446-acre arboretum maintains and displays many of the ornamentals
and flowering trees, shrubs and herbaceous garden plants found in cities, towns
and home landscapes throughout the United States. To these traditional
favorites, researchers there and in the
Floral and Nursery Research Unit in Washington, have added many of the
superior new floral and woody nursery plants now seen in public areas, as well
as in private gardens.
Old Glory and Declaration are two new Syringa cultivars
developed in the arboretums shrub-breeding program. Bred and initially
selected by the late USNA horticulturalist Donald Egolf and released by
Pooler, they follow the release of the Betsy Ross lilac in
2000. Old Glory and Declaration are each suited to a variety of landscape uses,
including as background plantings in shrub borders, as deciduous hedges, or for
mass-plantings in larger areas.
Old Glory was selected for its abundant fragrant, bluish-purple
flowers, rounded growth habit and disease-tolerant foliage. In 25 years of
testing in Washington, it grew nearly 11.5 feet high and a little over 13 feet
wide. Compared to other Syringa x hyacinthiflora types of lilac,
Old Glory has shown good field tolerance to Cercospora blight and
Pseudomonas syringae in warmer climates where these diseases are a
problem. It has also shown better-than-average tolerance to powdery mildew.
Declaration was selected for its fragrant, dark-reddish-purple
flowers, nearly foot-long flower clusters and open, upright growth habit. In 25
years of testing at the arboretum, it grew 8.5 feet high and about 6.5 feet
wide and also is well suited to a variety of landscape uses. However, it is
recommended primarily for traditional, cooler lilac-growing regions.
Both Old Glory and Declaration bloom in mid- to late April at the
arboretum, which is located in Plant Hardiness Zone 7a and has an average
minimum temperature range of 5 to 0 degrees Fahrenheit. Planting stock should
be available from a limited number of nurseries in 2006, and should be
available from retailers in 2008.