National Elm Trial in California • Established: 2005 • Terminated in 2009 by University of California-Davis

because of field space priorities • One specimen of eight cultivars were saved and are

displayed below • The first three years of performance were

summarized in a report found on this web site • Western Arborist, Fall 2009,National Elm Trial: Initial

report from Northern California • Greg McPherson, Larry Costello, James Harding, Steve Dreistadt, Mary Louise Flint and Skip Mezger

Emerald Sunshine (Ulmus propinqua)

Date: 8/23/2013 Diameter at 1.4m (cm): 11.3 Height (m): 7.0 Elm Leaf Beetle Chewing Damage Category: Least Damages: Extreme suckering at base See National elm trial: Initial report from Northern California (McPherson et al. 2009)

Note: Only one tree per species

Frontier (Ulmus carpinifolia X U. parvifolia)

Date: 8/23/2013 Diameter at 1.4m (cm): 11.0 Height (m): 6.4 Elm Leaf Beetle Chewing Damage Category: Least Damages: Sparse Foliage, suckering midway on trunk See National elm trial: Initial report from Northern California (McPherson et al. 2009)

‘Morton Glossy’ Triumph (U. pumila X U. japonica X U. wilsoniana)

Date: 8/23/2013 Diameter at 1.4m (cm): 17.5 Height (m): 7.4 Elm Leaf Beetle Chewing Damage Category: Intermediate Damages: Minor Leaf Damage due to insects See National elm trial: Initial report from Northern California (McPherson et al. 2009)

Ranked #2 due to crown shape, dense foliage, lack of suckering

Date: 8/23/2013 Diameter at 1.4m (cm): 24.9 Height (m): 6.2 Elm Leaf Beetle Chewing Damage Category: Intermediate Damages: Extensive leaf chewing on crown See National elm trial: Initial report from Northern California (McPherson et al. 2009)

New Horizon (U. pumila X U. japonica)

‘Morton’ Acolade (U. japonica X U. wilsoniana)

Date: 8/23/2013 Diameter at 1.4m (cm): 15.2 Height (m): 5.8 Elm Leaf Beetle Chewing Damage Category: Least Damages: Suckering midway on trunk See National elm trial: Initial report from Northern California (McPherson et al. 2009)

Patriot (U. glabra X U. carpinifolia X U. pumila) X U. wilsoniana

Date: 8/23/2013 Diameter at 1.4m (cm): 17.4 Height (m): 9.0 Elm Leaf Beetle Chewing Damage Category: Least Damages: National elm trial: Initial report from Northern California (McPherson et al. 2009)

Ranked #1 due to shape and dense canopy

Prospector (U. wilsoniana)

Date: 8/23/2013 Diameter at 1.4m (cm): 16.3 Height (m): 8.8 Elm Leaf Beetle Chewing Damage Category: Least Damages: See National elm trial: Initial report from Northern California (McPherson et al. 2009)

New Harmony (U. americana)

Date: 8/23/2013 Diameter at 1.4m (cm): 13.8 Height (m): 8.2 Elm Leaf Beetle Chewing Damage Category: Least Damages: See National elm trial: Initial report from Northern California (McPherson et al. 2009) Ranked #3 due to large leaves and columnar shape

McPherson et al. 2009

References McPherson, G., L. Costello, J. Harding, S. Dreistadt, M. L. Flint and S. Mezger. 2009. National Elm Trial: Initial report from Northern California. Western Arborist. Pp. 32-36. See National Elm Trial website for paper