If Utah had a “tree of the future,” it might have these features:
In a drought-riddled state, it wouldn’t guzzle water. In fact, it would need to thrive in a desert environment. And it would not increase water usage over the next five to 10 years.
The relationship between water and trees isn’t straightforward. One one hand, although a tree can absorb between 10 to 150 gallons of water per day, trees retain less than 5% of their water intake for growth, according to Purdue University’s Landscape Report. They release nearly 95% of it as mist.
On the other hand, trees can accentuate local water scarcity, decline local stream flows and deplete groundwater, according to Forests News. And all that water trees release back into the air often creates rainfall downwind, not necessarily where the water was absorbed.
The solution, however, is not to plant one kind of tree with particular features.
Marita Tewes, horticulture director at Red Butte Garden, said if one kind of tree was planted in place of others, it could be easily wiped out by disease or insects.
“You would never want to do a monoculture. You will always want a diversity,” she said.
Though a single, drought-resistant tree may not exist, trees as a whole can be a good landscaping choice even as experts say Utah’s water problems will persist.
The U.S. Drought Monitor shows nearly all of Utah is in severe or extreme drought. In April, Gov. Spencer Cox placed Utah under a state of emergency due to low snowpack, which is 25% below normal levels for this time of year.
Statewide reservoir storage is at 59%, according to the Utah Department of Natural Resources.
Almost half of the state’s largest reservoirs are below 55% capacity, down from the 67% capacity level they were at last year in 2021, data provided by DNR shows.
Tree options for Utah
Shaun Moser, conservation water park manager for the Jordan Valley Water Conservancy District, said trees are some of the more water-wise plants out there because trees’ deep roots can reach water where other plants can’t.
“Don’t automatically cut trees out of your landscapes,” added Lynsey Nielson, Red Butte Garden’s lead horticulturist for the terraces, orangerie and children’s gardens.
Here are suggestions from Moser, Tewes and Nielson:
crabapples
elms
zelkovas
honey locust trees
lacebark elms
Kentucky coffee trees
catalpas
Arizona cypresses
hackberries
New Mexico locusts
bur oaks
wavyleaf oaks
Osage orange trees
smoketrees
hawthorns
Besides their potential in water-wise landscaping, Tewes said trees reduce the energy needed to cool a house and can make the outdoors more enjoyable.
“I want to make sure that, instead of just letting everything die out, we focus our energy on the things that matter, and trees are a huge, huge part of that,” she said. “Maybe we have to let go of our lawns, but maybe we plant more trees.”
In Salt Lake, the Salt Lake City Urban Forestry Program provides most services related to city tree maintenance. When trees are removed, replanting generally occurs within a year.
The program aims to plant 1,000 new trees each year.
Salt Lake also has Mayor Erin Mendehall’s “ReTree SLC” initiative, which raises money to replace the 1,500 trees in public spaces that were lost during a Sep. 8, 2020 windstorm.
Think twice in Utah
Moser discouraged people from planting flowering pears. They are not long-lived, he said, and in urban environments tend to get planted in parking strips.
This makes them susceptible to everything from disease to trunks splitting to branches breaking off, he said.
He also recommended taking care when buying maple trees. Many come from the east coast, he said, and are used to much more acidic soil.
But several hybrid breeds, such as the crimson sunset, pacific sunset and Norwegian sunset maples, are adapted to alkaline soils. Tewes said silver maple, tatarian maple and some oaks can’t draw nutrients out of Utah’s alkaline soil.
And for those planting young trees for the first time, Tewes and Nielson reiterated the importance of training their root systems by watering less frequently but more deeply.
“When you water for a longer period of time, it wets the soil profile deeper and you encourage root growth that is deeper into the soil,” Tewes said.
Correction • May 31, 1:30 p.m.: A previous version of the story stated that Utah has acidic soil. Utah has alkaline soil.
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