USNA Floral and Nursery Plants Research
Germplasm Resources Information Network
USNA Woody Landscape Plant Germplasm Repository of the National Plant Germplasm System
Maryland DNR Forest Service, Urban and Community Forestry Program
Research Activities:
USNA New Breeding Program: The National Arboretum has developed a new focus on breeding trees specifically for street and utility line applications. Selections found to have potential are being propagated for on-street plantings and preliminary release to the nursery industry for further evaluation and production…Learn more ..
Pot-n-Pot Nursery: A pot-n-pot nursery was established to grow new tree selections exhibiting appropriate growth characteristics and adaptability for utility plantings. USNA grew 216 trees in a new pot-n-pot nursery and compared growth with typical field production practices, and analyzed data on tree growth to identify trees with best characteristics for use in urban utility sites. Trees were then a nalyzed trees through destructive sampling to compare pot-n-pot nursery production with field planting. Learn more….
Out Planting Activities: The Powertrees collaborative partnered with the Maryland communities of Greenbelt, College Park, and Hyattsville and in DC to out-plant trees and monitor their growth. Additionally, 79 Sycamore trees beneath high tension lines at Blair Montgomery High School were removed by PEPCO, a PHI Company. USNA and USDA Forest Service worked together to redesign and replant the site with smaller, urban adaptable trees. Learn more….
Why Powertrees Research? There is a great need for new selections and breeding of appropriate trees for utility line use.
Continued investigation into the factors that make a tree a good street utility tree is required to breed better adapted trees for utility use. Trees in urban environments are subjected to additional stresses beyond that of the general landscape, and increasingly are being planted in more restricted spaces.
What makes a good utility tree?
~ Size
~ Architecture
~ Pest Resistance
~ Disease Resistance
~ Stress-Resistance related to all of the insults street trees have to contend with such as snow removal chemicals, excessive heat and air pollution, compacted soil, restricted root zones, grey water, physical damage from car doors, etc.
Did you know there are also some not so obvious factors related to breeding and propagation?
~ Lack of 'trash fruit'
~ Non-invasiveness
~ Ease of clonal propagation (or uniformity and predictability of growth habit
~ High tolerance to abiotic stress. Abiotic stresses are caused by non living factors such as very high temperatures or physical damage.