Water-wise lawns: buffalo grass, blue grama, and a smaller turf
Where warm-season native grasses can replace a thirsty lawn, where they cannot, and how to water the lawn you keep.
A lawn is a use, not a default. In a semi-arid climate the square footage you mow is the square footage you will water, fertilize, and argue about in August. Denver Water’s xeriscape list calls this “alternative turf grasses”: a lawn only where it has a job, and a grass that matches the sun.
The practical lawn is the one in full sun, in a simple shape a sprinkler can hit, no bigger than the living you do on it. The rest of the yard can be the plantings on the xeriscape page and the regional plant pages.
Two native warm-season grasses do the job on many Front Range and high-plains sites: buffalo grass (Bouteloua dactyloides) and blue grama (Bouteloua gracilis). Blue grama is Colorado’s state grass. Both are at home in sun and in a summer-rainfall pattern, and both will go tan and dormant in a dry stretch, which is a normal resting state rather than a death.
If a tan lawn in August offends you, you will water it, and you should decide that before you plant. If a tan lawn is acceptable, you can cut the irrigation sharply once the grass is established, and green it up again when you choose to water or when rain returns.
Where these grasses work, and where they do not
They want full sun. A north side, a tree canopy, and a narrow strip between tall houses are Kentucky bluegrass problems or groundcover problems, not buffalo-grass problems. Buffalo grass in shade thins, weeds invade, and the water savings disappear because you are watering a failure.
They are warm-season. They green up late in spring and brown with the first hard cold, earlier than a cool-season bluegrass. On a mountain lot with a short summer they may be green for a disappointingly small number of weeks.
Above the elevations where a real summer exists, a smaller cool-season lawn or a meadow of local grasses is the more honest choice. A cabin at 9,000 feet is not a buffalo-grass project.
Traffic matters. A dog run, a daily soccer scrimmage, and a path to the alley wear buffalo grass and blue grama more than a play lawn of tougher mixed turf. Put the heavy wear where you are willing to water and overseed, and keep it small.
Blue grama is often used as a bunchgrass or as a fine-textured lawn from seed or plugs. Buffalo grass spreads by stolons and can knit a real turf in sun. Cultivars exist because the species is weedy-looking in its wild form for some tastes and beautiful for others.
Buy named seed or plugs from a supplier who sells for lawns, not a bag of “native mix” that is mostly annual weeds and a prairie flower you did not intend to mow.
Salt and compaction along a curb are a hard assignment for any lawn. A planted hellstrip from the Front Range plant list often beats turf there. Do not mow a two-foot strip next to a broiling sidewalk and call it a lawn plan.
Replacing a bluegrass lawn
Kill or strip the old turf completely. Buffalo grass seeded into a living bluegrass lawn loses. Late spring, when the soil is warm, is the seeding window for these warm-season grasses.
Seeding into a cold April soil wastes the seed. Plugs cost more and establish more predictably on a small area, especially if you can water them through the first summer and keep traffic off.
Water a new seeding lightly and often until the roots take, then stretch the interval.
This first-year schedule is not the low-water schedule. People who skip it conclude the species “doesn’t grow here.”
Mow higher than a golf course. These grasses are not bentgrass. A higher cut shades the soil and the crowns. Let clippings fall.
Do not fertilize on a bluegrass calendar. A light feeding, if the lawn is pale and a soil test agrees, is plenty.
Extra nitrogen grows a thirstier lawn and more mowing, which is the opposite of the project.
Weeds invade a thin stand. The answer is a denser stand: sun, establishment water, and patience. Herbicides that are safe on buffalo grass are a label question, and this site does not print rates. If the weeds are there because the lawn is in shade, change the plant, not the chemical.
If you keep a traditional lawn
Kentucky bluegrass and tall fescue are the cool-season lawns people already have. They can be managed on less water than a daily sprinkle, and they will look stressed while they do it.
Water deeply and less often, in the morning, to the depth of the roots, then wait until the lawn shows a footprint that stays down. That is the same probe logic as the drip page, done with a sprinkler.
Cycle and soak on clay so the water does not run into the gutter. Fix the spray so it is not watering the street. A broken head is a water bill.
Shrink the area before you change the species. Edging a lawn back to a shape that matches the spray pattern often saves more water than a new grass you will not maintain.
Aeration helps compacted clay more than another inch of sprinkler time. A soil test tells you if you need fertilizer at all. Many lawns are overfed and underwatered in the root zone, which trains roots to stay shallow.
Winter watering, on a mild day when the hose works, matters for new trees and sometimes for a lawn on a dry, open site. A brown winter lawn is fine. A tree that went into winter dry, in a soil that never got a fall soaking, is the casualty. Do not confuse the two.
A decision you can write down
| Situation | A workable lawn choice |
|---|---|
| Full sun, Front Range or high plains, tan in August is acceptable | Buffalo grass or blue grama, seeded or plugged in late spring |
| Full sun, you want green through a dry August | A smaller cool-season lawn, watered deeply and less often |
| Shade, north side, or a narrow side yard | Not buffalo grass. Groundcovers or a reduced cool-season patch |
| Short, cool mountain summer | Skip warm-season turf. Reduce the lawn or use a meadow that fits the elevation |
| Heavy daily wear | A small, tough, irrigated panel, not the whole yard in native grass |
| Hot parking strip | Planted xeriscape, not turf |
Checklist
- Draw the lawn at the size you use, in a shape you can spray without watering pavement.
- Choose buffalo grass or blue grama only in full sun, and only where a dormant tan is acceptable.
- Seed warm-season grasses into warm soil, not in a cold April.
- Water establishment honestly the first summer, then back off.
- Mow high and go easy on nitrogen.
- On clay, cycle the sprinkler so water soaks.
- Keep trees and xeric beds off the lawn valve.
- If the lawn is failing in shade, replace that piece instead of watering it harder.
Sources
- Denver Water, xeriscape principles, practical turf areas and efficient irrigation.
- CSU Extension, Colorado Vegetable Guide, on the semi-arid setting and wind, which is the climate a lawn has to live in.
- Colorado’s designation of blue grama as the state grass, for the species’ regional standing.
- CSU Extension yard and garden publications on lawn watering and care, via extension.colostate.edu.