The unique environmental conditions of Colorado—high altitude, arid climate, intense sun, and significant temperature fluctuations—present a distinct challenge for maintaining a green lawn. Successfully growing grass depends entirely on selecting a species adapted to this demanding environment. Choosing the wrong turfgrass leads to an unsustainable landscape that requires excessive water. Understanding the two primary categories of lawn grasses is the first step toward establishing a resilient turf.
Cool-Season vs. Warm-Season Grasses: Adapting to Colorado’s Regions
Colorado’s diverse geography, spanning high mountain elevations, the urban Front Range, and the expansive High Plains, dictates which type of grass is most appropriate. Turfgrasses are classified into cool-season and warm-season types based on their optimal growth temperatures.
Cool-season grasses thrive when air temperatures are between 60 and 75 degrees Fahrenheit, making their most active growth periods spring and fall. These grasses are the standard for traditional, irrigated lawns along the Front Range and at higher elevations where cooler temperatures persist.
Warm-season grasses prefer warmer temperatures, growing best when temperatures range from 80 to 95 degrees Fahrenheit. Their active growth is concentrated in the summer months, and they enter a brown, dormant state earlier in the fall and remain dormant later into the spring. These grasses are typically better suited for the High Plains and areas with extreme heat and severe water restrictions.
Top Cool-Season Grass Recommendations
Kentucky Bluegrass (KBG) is the most common cool-season choice for traditional lawns along Colorado’s Front Range. KBG is a sod-forming grass that spreads through underground stems called rhizomes, giving it an exceptional ability to repair itself from damage caused by foot traffic. This makes it resilient for heavily used residential lawns and sports fields. However, KBG requires significant water to maintain its dark green color, often needing 24 to 30 inches of supplemental irrigation annually.
Tall Fescue is a highly valued cool-season option, particularly for homeowners seeking a more drought-tolerant alternative. Its deep root system, which can reach two to three feet in depth, allows it to access deeper soil moisture and provides superior heat and drought resistance. Tall Fescue is a bunch-type grass, meaning it does not produce rhizomes and cannot self-repair, which can lead to clumping in high-traffic areas. It exhibits moderate shade tolerance and requires fewer fertilizer inputs compared to KBG, making it a lower-maintenance choice.
Perennial Ryegrass is primarily used in Colorado for overseeding existing lawns because of its rapid germination speed, often sprouting within five to ten days. This fast establishment makes it effective for quickly filling in bare patches or creating a temporary green cover. As a bunch-type grass with a shallow root system, it has low drought tolerance and tends to struggle during the hottest summer months. While it tolerates foot traffic, its inability to spread means that worn areas will need to be reseeded.
Drought-Tolerant Warm-Season Options
For homeowners prioritizing water conservation and low maintenance, particularly in the High Plains or drier, lower-elevation areas, native warm-season grasses are the preferred alternative. Buffalograss is a native species that thrives in Colorado’s arid conditions, requiring only about one-third of the water necessary for a Kentucky Bluegrass lawn. It is extremely drought-tolerant and handles the region’s typically alkaline soils well.
Buffalograss and its frequent companion, Blue Grama, are both slow to establish from seed, often taking a full growing season to mature into a dense turf. They have lower traffic tolerance compared to cool-season grasses, making them less suitable for heavily used areas. A key characteristic is their dormancy: they turn green later in the spring (around May) and turn tan with the first hard fall frost, remaining dormant until the next growing season. Blue Grama is noted for its distinctive, flag-like seedheads and greater tolerance for higher elevations, making it viable for sites up to 6,800 feet.
Essential Care and Maintenance for High Plains Lawns
Proper watering is the single most important maintenance practice for a healthy Colorado lawn due to the semi-arid climate. Lawns should be watered deeply and infrequently to encourage the development of deep root systems, which increases drought tolerance. Watering in the early morning is recommended to minimize water loss from evaporation and wind. Cool-season grasses typically need 1 to 1.5 inches of water per week, while established native warm-season grasses may need water once per week or less.
Mowing height also plays a large role in the long-term health of a high-altitude lawn. Keeping the grass blades higher, generally between 2.5 and 3.5 inches, helps shade the soil and keeps the grass roots cooler. Taller grass reduces water evaporation and allows the plant to photosynthesize more efficiently in the intense Colorado sun. Never remove more than one-third of the grass blade height in a single cutting to avoid stressing the plant.
Colorado’s native soils are frequently clay-heavy and alkaline, which impedes water absorption and nutrient availability. To combat this, core aeration should be performed regularly, ideally in the fall, to reduce soil compaction and allow air, water, and nutrients to reach the roots. Fertilization is best done in the spring and fall for cool-season grasses to promote strong root growth and recovery from summer stress. For warm-season grasses, a single application of nitrogen fertilizer in mid-summer is sufficient to support their growth.