EDUCATION

Azalea Tours and Rhododendron Show

Walk & Talk: Azalea Collection Tours
May 9, 10:00 am – 12:00 pm;
May 11, 10:00 am – 12:00 pm (Mother’s Day – bring Mom!)
Azalea Collection

Nothing says ‘spring’ in the garden like thousands of brilliant blooming azaleas. Join our enthusiastic Azalea Collection curator for a walk along our woodland trails and learn about all aspects of azalea history and culture. The arboretum’s collection is unique because hundreds of new varieties were developed here for gardeners by arboretum scientist and director Benjamin Y. Morrison. Fee $19. Registration is required.

Rhododendron Show
May 10, 10:00 am – 4:00 pm
Administration Building Auditorium

Blooms of every color and form are artfully displayed in this annual show presented by the Potomac Valley Chapter of the American Rhododendron Society. All show entries are varieties which are well suited for growing in our area, and are labeled and identified. Friendly and knowledgeable chapter members will be on hand to answer questions and provide information about the plants displayed. Do you have an unknown rhododendron in your garden? Bring a small branch with flowers and we will try to identify it for you. Free.

Presentations by chapter members:
11:30 am - Native Azaleas of Gregory Bald, in the Great Smoky Mountains
1:00 pm - Tips on Growing Rhododendrons & Azaleas
2:00 pm - Native Azalea Species "Gems in the Wild"
3:00 pm - Native Azaleas of Gregory Bald, in the Great Smoky Mountains

  View Arboretum Calendar of Events

HORTICULTURE

Emerald Ash Borer Update

As we welcome in the spring season, it is a good time to review the battle to control the emerald ash borer in the United States, which is now in its sixth year. This introduced exotic pest has killed more that twenty five million trees (see image at left of trees in decline), and in spite of tens of millions of dollars spent on control measures, this insect is spreading to an ever widening area. The emerald ash borer will have a major impact in all locales where ash trees are dominate, either as landscape and street tree specimens or in native woodland populations.

This Asian beetle, beautifully iridescent green in color, was discovered in Michigan in 2002. It is believed to have been imported in wooden pallets and may have been undetected for more than ten years. By 2005, the emerald ash borer had spread to Ohio, Indiana, and Illinois, with an isolated outbreak in Maryland. This pest continues to extend its range, now established in western Pennsylvania and most recently in Fayette County, West Virginia. While other ash boring insects seem to infect weak or dying trees, the emerald ash borer can infect large healthy trees, killing them within one to three years.    Read Full Story.

RESEARCH

U. S. National Seed Herbarium Moves to the Arboretum

The world’s largest and most diverse systematic collection of seeds of flowering and coniferous plants is now part of the National Arboretum. The seed collection was transferred to the Arboretum's Floral & Nursery Plants Research Unit in late 2007 from the Plant Sciences Institute of the Beltsville Agricultural Research Center in Beltsville, Maryland, where it resided for many years. The collection contains approximately 125,000 dried seed and fruit samples from plants throughout the world. Over 27,000 different species of plants representing 397 families and 13,000 genera of plants are represented in this valuable collection. The samples are stored in either glass vials or plastic bags. The entire collection is kept in a secure, moveable compact storage facility.

The National Seed Herbarium serves several important roles, including helping to document biodiversity and seed types of species, varieties, and cultivars, some of which may be extinct. It is an important tool for identifying unknown seeds, and it supports research programs relating to seeds. The collection also serves as the primary source of information for the most important references for seed identification of noxious weeds, legumes, and families of seed plants published by the USDA. The Seed Herbarium is a companion to and complements the arboretum herbarium, which contains over 600,000 dried specimens of twigs, branches, flowers, and fruits of the world’s flora.    Read Full Story
 
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