2017 March 29
22 two new trees will be planted in Alamosa parks and the cemetery this spring. We’ll plant many of the trees – and we hope with your help – during Alamosa Arbor Week, April 22 -28.
Of the seven varieties four are considered large trees and will reach heights of 50 feet at maturity: Blue Spruce (Picea pungens), Sensation Boxelder Maples (Acer negundo ‘Sensation’), Narrowleaf Cottonwoods (Populus angustifolia), and Hackberry (Celtis occidentalis). Four Spruce are slated for the cemetery. Three Boxelder Maples, also known as Manitoba Maples, should do well in open park areas. According to the Colorado Tree Coalition (CTC) website, “The right angle branching and strong central leader growth habit makes this tree a good choice for streets and parks.”
Why is this important? As I’ve mentioned in previous articles, most deciduous trees grow better if they have one central branch that is taller than the others. If branching angles are wide, the tree is less likely to have competing, parallel branches that push against each other as they mature. If they do push together, it is likely that cracks form producing a high risk for branch failure in the future.
They are rated to be hardy down to -30 deg. F which makes me a bit nervous as we have had record lows in the minus 30’s in January. However, the lowest January temperature recorded for Alamosa this century was -32 deg. F. On the positive side, they grow well at elevations up to 9,000 ft., are drought tolerant once established, and have attractive red leaves in the fall.
Concerned about Boxelder bugs? The CTC website reports that these Boxelders are male and are much less attractive to the bug and that none have been observed on trees planted in western Colorado landscapes.
We see a lot of Narrowleaf Cottonwoods in Alamosa and we’ll have three more this spring. They are fast growing (even in Alamosa), cold hardy to -50 deg. F, and do well at elevations up to 8,500 feet. There are a couple of drawbacks to my way of thinking: 1) they need quite a bit of water, and 2) they sucker like crazy. I have one in my backyard and love the height and shade, but grit my teeth at pulling and cutting so many suckers -- as far away as 50 feet.
I don’t know of any mature Hackberry trees in town. The Alamosa Tree inventory lists 17 specimens of which 14 are in parks – all of them have been planted in the last 10 years. Three more will be planted this year. While listed as a large tree, they are slow growing in our climate. I have one in a dry spot in my yard and it is doing very well. It’s cold hardy to -50 deg. F and is “very water thrifty” according the Tree Farm website. Some people are concerned that our elevation is about 7,500 ft. and its maximum elevation is listed at 7,000 ft.
On the smaller side, we’ll see three each of Tatarian Maples (Acer tataricum garann "Hot Wings"), Spring Snow Crabapples (Malus 'Spring Snow'), and Skyline Honeylocusts (Gleditsia triacanthos inermis "Skyline"). I love all of these! I have one of the Maples and one of the Crabapples and they are doing well. I encourage people to plant smaller trees in their yards as over the years they require less attention and water and still provide shade for people. There are two Maples on the north side of Main St., one in the 500 block and the other in the 700 block. They have showy red samaras (winged seeds) and the leaves turn red in the fall. They are very drought tolerant and hardy to -40 deg. This is another species that has a maximum elevation listing of 7,000 ft. All the ones I know of in Alamosa seem to be doing well.
We’re seeing more and more Spring Snow Crabapples around town. They have beautiful white blossoms in the spring and are fruitless (which many see as a bonus as they aren’t as messy). They’re cold hardy to -35 deg., are drought tolerant once established, grow slowly, and do well to 8,000 ft.
Skyline Honeylocust is listed as a medium-sized tree growing to about 40 ft. I notice several websites list the maximum elevation for this tree as 6,000 ft. and cold hardiness to -30 deg. F; however, our tree inventory lists nearly 50 Honeylocust, many of which are Skyline. It has deep roots so does well in lawn areas as it doesn’t compete with lawn for water near the surface as many other trees with shallow roots do.
“I give you oxygen to live and you kill me. Save trees!” Harpreet Sandhu