Alamosa Trees: Arbor Week and pruning

Please help plant trees on May 4 at noon or 4 p.m.! We’ll provide shovels if you don’t have one. Alamosa will celebrate Arbor Week (April 26 to May 5) by planting trees under the lights along the east side of State Avenue by the Alamosa Cemetery. The Department of Parks and Recreation along with the Tree Board received a $3,000 grant from the XCEL Energy Vegetation Management/Colorado Tree Coalition (CTC) grant program for the “Greening Alamosa’s Airport Gateway Corridor under Powerlines” project.

Many visitors to Alamosa fly into the San Luis Valley Regional Airport on the south end of the city. State Avenue is the main approach to downtown and much of the southern portion is devoid of landscaping.

We have the opportunity to green up the area. Combining grant funds with City funds, we’ll plant 20 trees. Also, an automated watering system will be installed this summer.

To insure a healthy, long lived line of trees, we selected a variety of species that are appropriate for planting under powerlines and for our enduring our challenging environment. The list includes: 3 Canada Red Chokecherries (Prunus virginiana), 3 Bristlecone Pines (Pinus aristata), 3 Hot Wing Tatarian Maples (Acer tataricum garann “Hot Wings”), 3 Spring Snow Crabapples (Malus Spring Snow”), 3 Toba Hawthorn (Crataegus x mordenensis  Toba’ ), 3 Gambel Oaks (Quercus gambelii), and 2 Moonglow Junipers (Juniperus scopulorumMoonglow”). 

You can read more about these trees at the website. Please be aware that the powerlines we’ll be planting under may be higher than powerlines in your neighborhood. Before planting any trees under powerlines, make sure that their height at maturity will not interfere with the lines. We hope to see you Friday, May 4.

Colorado State Forester Vince Urbina presented another informative and enjoyable pruning and tree care workshop in Center last week. While I’ve attended several pruning workshops, I always learn something new and particularly appreciate the opportunity to walk around an area to discuss and properly practice pruning. This time we wandered the Center school campus and the Community Park west of the school.

I’ve written several articles on pruning in the San Luis Valley (click on the “News & Blog” tab at so I’ll try to not repeat too much of that information in this article

Now is a good time to prune in the SLV. Before pruning, make sure you know why you are pruning. For example, if you have an ornamental such as the Spring Snow Crabapple, you prune it to look pretty. If you have a shade tree, you prune it to produce a shaded canopy. 

And always, prune for safety first. If there are hanging or dead branches they should be removed immediately, before they become a hazard. As shade trees mature, they should be pruned so that their bottom branches are eight ft. above the ground. This is especially true on school grounds (keeps ever adventurous kids from pulling on the branches) and above sidewalks.

When should you first consider pruning a tree you planted in recent years? Assuming you chose a good tree at the nursery, you can wait until it’s established. If last year’s growth was 4-6 inches of stem, it’s probably OK to prune. Container trees usually get established faster than ball-and-burlapped trees. Properly grown container trees have their entire root system while B&B trees have only about 10-15 percent of their roots. It takes B&B trees about a year to recover for every inch of caliper (the diameter of the trunk 6 inches above the soil).

If you have Canada Red Chokecherries or Spring Snow Crabapples you’ll probably notice suckers popping up around the base of the tree. They should be removed by digging down to the junction of the sucker and the root and cutting them off there. If you just snip them at ground level Vince says, “It’s like throwing gas on a fire.” They just come back with a vengeance.

One person queried, “If the main trunk seems to be dying can you just let the suckers take over?” Vince replied that you could, but you would not know what you’re getting. These special chokecherries and crabapples (along with many other trees) are created by placing a bud of the desired tree species on hardy root stock of another variety or species. Since the suckers sprout from the root stock, you won’t get the tree you originally wanted.

“Planting trees, I myself thought for a long time, was a feel-good thing, a nice but feeble response to our litany of modern-day environmental problems. … my thinking on the issue has changed. Planting trees may be the single most important eco technology that we have to put the broken pieces of our planet back together.” Jim Robbins, “The Man Who Planted Trees”