Let’s Talk Water and Yes, Native Plants Too

| Colorado Native Plants, Native Landscape Planning & Design, Turf Conversion

By Deborah Lebow Aal

Ah, yes, water. It IS the weather in Colorado.  We are constantly talking about water. Skiers are obsessed with the snowpack; anglers are obsessed with river flow; farmers talk about the drought that seems to be omni-present. But, is it really a drought if it’s the normal condition? Denver gets an average of about 15 inches of precipitation every year (and that number varies slightly over the Front Range). In 2018, a very dry year, Denver received approximately 8.5 inches. Compare that to New York City, which gets a whopping 45 inches annually, or Chicago, which gets 36. And, yet, we try to plant the same things they do there. Many of us have relocated here from places with lush green landscapes, and we want that here, when there isn’t water available to support it.

And, do you know where the water used on the Front Range comes from? It’s complicated, but for the most part, it is piped over from the Western Slope and sits in 15 or so different reservoirs along the Front Range, before it is piped down to your faucet. But you probably knew that…. It takes a lot of energy to pipe water many miles, over a mountain pass or two, but you probably knew that as well. And therefore you know that it behooves us to be careful with our water. 

Worrying about water does keep me up at night. It’s very dry here. But, to put our water use into perspective, a whopping 86% of Colorado’s water is used for agricultural irrigation. Eighty-six percent! Clearly something has to change with agricultural water use, but we also should be careful with our residential irrigation water. Of the water used on the Front Range, 50-55% is used for residential outdoor irrigation. We know this because in January, when lawns are (hopefully) covered with a blanket of snow, and no one I know is watering their lawn, the daily average use is 110 million gallons per day. In August, that number is 297 million gallons a day. Clearly, the landscaping we choose to have around our homes is a very significant factor in our water use.

How much water do you use? Last January, my family (two adults) used 1,000-2000 gallons of water.1  In a dry August – and we are pretty certain to have a dry August – we use 2,000 – 3,000 gallons of water. Though we double our bill, we are still one of the lowest users of water in our neighborhood (your bill compares you to your neighbors). And my bill doubles in August because I do water with a hose, by hand, when I feel the plants need it. I believe our water usage is low because we have zero Kentucky bluegrass, and in its place, many native plants. We also have a small-ish urban lot.  On a comparable, in fact slightly smaller, lot, one of my neighbors with Kentucky bluegrass uses 2,000 gallons in January, and 11,000 gallons in August! That’s 9,000 gallons in one month primarily to support Kentucky bluegrass.

So, what can you do to reduce outdoor water usage at your house? You can start by reducing the size of your Kentucky bluegrass lawn. That water-thirsty lawn is not just a dead zone for anything but Canada geese (nothing against them) and Japanese beetle larvae (everything against them). It requires a lot of water to keep lush and green, which amounts to higher costs. A 5,000 square-foot patch of Kentucky bluegrass, watered ½ inch every third day uses 18,500 gallons of water per month.2 Think of the money you can save!

Blue Grama Grass (Bouteloua gracilis)
Blue Grama Grass (Bouteloua gracilis)

You can replace that thirsty lawn with a NATIVE xeric landscape. You all know what xeric means – it means adapted to a dry environment.  Denver Water coined the term “xeriscape” in the 1980s to mean a style of landscape requiring little to no irrigation. If you look it up, you will find many entries on how to “xeriscape” your yard, using xeric plantings. But you find very little on native xeric planting. Part of the mission of Wild Ones is to facilitate a change in landscaping by promoting NATIVE xeriscaping. And you have to be careful with both pieces of that. Not all native plants are water-wise, and certainly not all plants advertised as xeric, are native. Native plants will give you added ecosystem benefits that non-native plants will not. 

Buffalo Grass (Bouteloua dactyloides)
Buffalo Grass (Bouteloua dactyloides)

An example of a favorite go-to (dare I say overused?) xeric plant is ‘Karl Foerster’  Feather Reed grass. It is a beautiful ornamental grass that grows very well here, but it is NOT native to Colorado. It is a hybrid of two species native to Europe and Asia. You can find many native grasses that would be just as beautiful and also fill an ecological niche that Feather Reed Grass does not. Grasses like Blue Grama (Bouteloua gracilis) and Side-oats Grama (Bouteloua curtipendula), while not quite as tall, would fit the bill. Both are native and xeric, and are larval hosts for skipper butterflies. If it’s height you’re after, Indian Grass (Sorghastrum nutans) is a good alternative. The big difference between Feather Reed Grass and Indian Grass is that Feather Reed Grass is a cool season grass and so reaches its mature height and blooms in June; Indian Grass blooms in the fall.

As an alternative to turf, we have the native Buffalo grass (Bouteloua dactyloides). Buffalo grass is a warm season grass, which means it goes dormant as temperatures cool and day length shortens, and it stays brown until the weather warms in late spring.  So, it’s not exactly like Kentucky bluegrass. But – and this is a big plus –  because it is kept on the dry side, it is a far less appealing place for Japanese beetles to lay their eggs. As Blue Grama and Buffalo grass are low stature, short-grass prairie species, they require little mowing if substituted for a lawn. In addition, a 5,000 square-foot patch of Buffalo grass watered ½ inch every two weeks (yes, that’s all it needs) uses 3,000 gallons a month.3  So that’s at least a 14,500 gallons of water per month savings, replacing Kentucky bluegrass with Buffalo grass. I do know people who never water their Buffalo grass, and it looks fine, so it could be even more of a savings.

I challenge you to look closely at your water bill. What is your average usage in January, and what is your average usage in August? And how many more gallons of water, pumped from the Colorado River Basin and the Western Slope, are you using for your landscape? We can all use less. Think NATIVE xeriscape.

  1. Denver Water says the average 2-person Denver Water customer uses 2,440 gallons per month ↩︎
  2. Numbers from Colorado State University Extension Fact Sheet – 9.952 on Water Conservation ↩︎
  3. Numbers from Colorado State University Extension Fact Sheet – 9.952 on Water Conservation ↩︎

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