Well, the title says it all. The days of lush bluegrass lawns on the Front Range are in their twilight, for a number of reasons that seem obvious, but maybe are not so obvious to newcomers to Colorado.
Bluegrass is a thirsty, heat-hating, shallow-rooted non-native that was never terribly well-adapted to the rigors of life in the high desert. It requires 2.5” of water per week or even more in sandy soils during the growing season. Its annual water requirement is 3x our normal annual average precipitation. Our prolonged drought and lack of summer monsoons in recent years have made these water requirements overbearing. Its root system is mostly in the top 6-10” of soil, with only a few roots on average going much deeper than that, leaving the plant susceptible to drought and high soil temps. Our soils tend to the alkaline side and make nutrient absorption more challenging for bluegrass, which requires an abundance of nitrogen to flourish. And as our temperatures locally get hotter each passing summer, we have left the comfort zone of bluegrass, which really begins to struggle when temps hit the high 80s, and shuts down when our temps hit the prolonged 90s that are becoming the norm in high summer.
As Colorado Springs experiences a growth boom, the amount of runoff (our vital water supply) in the Arkansas, South Platte, and West Slope watersheds upon which we rely has become more erratic and less reliable year after year, due to prolonged, recurring drought. As most long-term residents have learned, a hot, dry summer with water restrictions is generally the end of a sodded bluegrass lawn, as the grass slowly goes dormant and then dies due to high evaporation and low water. With an increasing population locally, this cycle becomes more important, as water restrictions become the norm, in order to preserve drinking water supplies for a growing population.
Even when it is possible to sustain lush bluegrass lawns here (our occasional cool, wet summer), is that really the best usage for a water supply that is so scarce, requires so much effort to move, and is taken away from streamflows, to the detriment of the watersheds? Even in our rainiest, most optimal summers, bluegrass requires irrigation.
As we face another likely dry, hot summer, this is a good time to ask yourself if there is a better way than bluegrass. Tall fescue is a more durable lawn, and though it also requires irrigation, it is more deep-rooted, heat-tolerant, and drought-tolerant than bluegrass. It’s really the best choice left for our changing climate if you must have a conventional lawn.
Native lawn substitutes like Buffalograss and some wheatgrass species also bear consideration, as they generally require few inputs and not much water. While not perfect, flawless turf, they do make a passable lawn once established.
Planting shrubs, trees, and flowers in place of lawn creates wildlife habitat, generally uses less water if well-planned, and also helps sequester some carbon pollution back to the soil. Trees in particular can change your whole landscape, cool your house in summer, and block winter winds, if sited correctly.
This subject is always a touchy one. Aficionados of verdant bluegrass lawns are not always receptive to the idea that such a lawn is completely out of place in this environment, and offers little in the way of habitat, carbon sequestration, or wise water use. But having been here for a very long time now, and having replanted the same bluegrass lawns over and over for the same people every time a drought does lasting damage, I am convinced that there is a better way, and that better way need not be a yard full of rocks!
Drought is the norm here. Those who plan for that norm typically have more successful landscapes. Just a basic fact of living in this beautiful but somewhat harsh place, where the Great Plains meet the Rocky Mountains, on the dry side of the Divide.