Carolina silverbell (Halesia carolina) produces fruits that look more like winged footballs than bells. Thus, one taxonomic synonym for this tree is Halesia tetraptera, where tetraptera means “four wings.” Carolina silverbell falls in that category of urban trees that are best used in parks, campuses, generously wide tree lawns, and other places where the influence of the built environment (asphalt, concrete) on the soil pH is not too profound. This is because it can’t tolerate highly alkaline soil and indeed prefers acidic soil where possible. In high pH-soils, its leaves can appear chlorotic (yellowed).
There’s some disagreement about the true native (vs. naturalized) range of white fringe tree, Chionanthus virginicus. Although it appears to be indigenous to the Southeast U.S. at least, the potential planting range of this small tree, hardy to USDA Zone 3, is the entire continental U.S. Unfortunately, white fringe tree has been found to be quite vulnerable to Emerald Ash Borer (EAB) like its Oleaceae family cousins, ash trees.
Interestingly, Chinese fringe tree (Chionanthus retusus) has not been found to be vulnerable to EAB. It’s thought that since C. retusus co-evolved with EAB, this Asian iteration of fringe tree built up defenses to the beetle over millennia in its native eastern Russia, northern China, Japan, and Korea.
Each year, members of the Society of Municipal Arborists (SMA) vote for the SMA Urban Tree of the Year. Praise for this year’s winner, American hophornbeam (Ostrya virginiana), came from fans in states as far-flung as Wisconsin, New York, Virginia, and Texas.
Here, we hear from the Council’s Dr. Nina Bassuk at Cornell and from her colleague, Dr. Eric Wiseman at Virginia Tech. You can see the full list of SMA Urban Trees of the Year going back to the program’s inception in 1996 here.
The Fall Fiesta sugar maple (Acer saccharum ‘Bailsta’) is a patented cultivar selected in 1987 from a group of seedlings at Bailey Nurseries in Yamhill, Oregon. It was chosen because of its vigorous growth rate; upright, symmetrical form; and leathery leaves that are resistant to scorch and tatter caused by droughty or windy conditions, respectively.
Fall Fiesta is an excellent shade tree with a dense, rounded crown; it maintains its shape and requires little pruning. Its fall color may consist of more oranges and reds than other sugar maple varieties, and it exhibits excellent winter hardiness, from USDA Zones 3 to 8. Healthy trees don’t have significant pest or disease problems.