By Marilyn Loser
The previous installment of this column described the “Front Range Tree Recommendation List (FRTRL)”*, commented on its usefulness in Alamosa, and related comments by local nursery/greenhouse women Stephanie Coley (North River Greenhouse and Landscaping) and Ruthie Brown (Alamosa Green Spot). As stated previously, our environment is harsher than the Front Range, but the list still provides useful guidance in helping Alamosa diversify its Community Forest.
The last column discussed maple trees, but there are many other appropriate trees. In recent years a more diverse tree palette has sprung up in Alamosa. Ruthie says that it usually takes until the third year for a new tree to really take off .
Locust trees are popular at both local establishments. Thornless common Honeylocusts (gleditsia triacanthos v. inemis) Shademaster (visit Cole Park to see 2010 plantings) and Skyline rate the “A” list with the caution to wrap young trees to protect the tender bark.
The North River Greenhouse also sells the Black Locust ‘Purple Robe’ (robinia pseudoacacia) which has stellar clumps of fragrant blossoms and was beautiful in Alamosa early this summer. It rates the “D” list due to possible borer damage. The few specimens I’ve seen in town don’t display borer damage symptoms such as dead, broken branches. I don’t know if our cold temperatures discourage the pest. Anyone know?
Ash trees are always popular as they grow relatively quickly in Alamosa. The Fraxinus species, which include the Autumn Purple, Patmore, and Marshall’s Seedless only earn a position on the “B” list as they are susceptible to a bore which has not yet been detected in Colorado. The Oak Leaf Mountain Ash (sorbus thuringiaca) is one of my favorites and is doing well around southern Colorado according to Ruthie. It only receives a “C” on the list due to limited observation. Trap wrap is suggested for young trees with tender bark. I just planted one this summer and will wrap the trunk this fall.
Canada Chokecherries (prunus virginiana) received a “B”. This is one of my favorites locally and is sold by both nursery/greenhouses. Its leaves start out green and turn purple. The birds love the berries. The FRTRL notes that it suckers. Mine only sucker close to the trunk, but I’m willing to trim it back as I love the purple foliage and graceful form. This tree is a close relative to our native chokecherry shrub.
A favorite in Alamosa are crabapple (malus) trees as they are cold hardy and burst with color in early May when we’re weary of the long winter. Surprising to me is the “C” rating for Robinson Crabapples which indicates the Front Range doesn’t have a lot of experience with the tree. The one is my front yard is more than 30 years old. It has beautiful dark pink blossoms and is less disease prone than the Hopa Crabapple which is also found in the Valley. I think due to our cold temperatures, crabapples aren’t very disease prone here. The FRTRL notes the Hopa has messy fruit.
White flowering, fruitless (and less messy) Spring Snow Crabapples are increasingly popular in town and earn an “A” on the Front Range list.
On the “B” list are native Aspen (populus tremuloides) and Swedish Aspen (populus tremula erecta). The North River Greenhouse is now carrying the Swedish Aspen which is more columnar in its leafing habit and has more serrated leaves than our native aspen that tends to have a high crown and bare trunk as it ages. Ruthie doesn’t encourage our native Aspen or many other populous species for yards as they tend to sucker. “You see more suckers around town this year due to the stress of wind and drought,” says Ruthie. On the other hand, they are cold hardy and do well at our altitude.
I encourage you to visit our local retailers and plant a tree! We need more.
Native Plants Garden: Take a walk around the Alamosa Visitors’ Center and view the new native plants garden installed by the Alamosa Convention and Tourism Bureau. Many of the plants are labeled. It’s worth the visit.
*Find the list on the web at http://www.ext.colostate.edu/pubs/garden/treereclist.pdf. For the Alamosa Tree list go to http://www.AlamosaTrees.net and click on the Tree Lists tab.
“Breeze is the conductor, trees the musicians, leaves the instruments.” Nathaniel LeTonnerre