2015 July 29
In Alamosa we are not experiencing severe drought this year as are Southern California and many places in Washington State. However, drought is relative. We’re very dry and have had several drought years recently.
We’ve had 1.14 inches of rain so far this July compared to average of .66 inches according to the Wunderground weather site. In fact, we’ve had 6.27 inches so far this year compared to the average 3.37 inches. However, this doesn’t mean our trees don’t need supplementary water to thrive.
Southern California is usually quite dry so trees are better acclimated to low moisture while those in Washington are used to more moisture and many are having a tough time adapting. In fact, many of their tree species require amounts of moisture unheard of in Alamosa.
“According to a parks department survey ending in April, as many as 14,000 trees in L.A. parks – about 4 percent of the total – may have died during the last year of drought,” reported the Los Angeles times in June. “The year before that o, officials said only about 1 percent of trees were found dead.” Mature trees may be hit particularly hard.
Rachael Malarich of the environmental group Tree People says trees need time to get used to not having the amount of water they previously had. She says even native or drought-tolerant plants need time to adjust to a new watering cycle.
So if a tree previously was being watered every day by lawn sprinklers, that process should be slowly wound down over weeks and months. In fact, Malarich says some trees can take up to five years to adjust to drier conditions.
Alamosa water rates have increased and while July has been a bit cool, we need to remember that 2014 was the warmest year ever reported on Earth. The trend is towards warming.
I’ve been happily riding my bike around town this summer and I’ve noticed several things. A number of people have severely cut back on watering their yards and some have stopped altogether. I’ve noticed a number of new houses with expanses of very green lawn and no trees. I’ve noticed some yards that are all gravel.
All of this concerns me! So what does that mean for Alamosa? Trees provide shade, beauty, and habitat. Yards with no trees are much hotter; cities with few trees are much hotter. In the last few years I’ve seen more swamp coolers hanging off of windows around town. There’s a trade-off here! More heat, more electricity to run those coolers. Perhaps cooling trees are a better option.
Green grass sod is easy for developers to plop down and it looks nice for a while. But the cost of upkeep – watering, mowing, and fertilizing is high. Placing a tree in the middle of a lawn look nice, but in our arid climate it probably won’t get as much water as it needs. Lawns are often watered several times a week and need only a few inches of moisture. Mature trees need water to a depth of at least two feet and do much getter with infrequent, deeper watering.
Linda Eremita, an arborist with Tree People, says for mature trees that have acclimated to drier conditions, you should only need to give it a soak once a month, depending on the soil and type of tree. If we have hot, dry, windy weather, I think you may need to water twice a month in Alamosa.
If you don’t want to install a serious drip system, you can buy inexpensive soaker hoses. Lay the hose in a spiral coiling out from the tree. Make sure the hose extends to at least the outside edge of the canopy. You can adjust the outward coils as the tree grows. Worried about forgetting to turn the hose off? Invest in an inexpensive timer.
To reduce evaporation, use light colored mulch. Make sure to remove grass and weeds from around trees as they compete for water and nutrients.
Choose trees that are more drought resistant. I suggest selecting a medium-sized variety. Most of the houses in Alamosa are one-story. Smaller trees require less water throughout their lives and are easier to maintain as their canopy isn’t so far off the ground!
I encourage you to contact your favorite greenhouse/gardening center and to download State Colorado Forester Keith Wood’s “Drought-Tolerant Trees for Colorado Landscapes” at http://static.colostate.edu/client-files/csfs/pdfs/droughttrees.pdf .
A number of these trees are doing well in Alamosa. My favorites are Honeylocust, Hackberry, Hawthorn, Bur Oak, Amur Maple, Tatarian Maple, Canada Choke Cherry, and Crabapples.
“Sadly, it’s much easier to create a desert than a forest.” James Lovelock