When to Plant New Lawn Seed in Denver, Colorado?

Denver lawns have a 155-day growing season.

The Mile High City has a semi-arid climate and a growing season of approximately 155 days from mid-May to early October. Actual frost and freeze dates, as in any high altitude location, may vary from year to year.

Considerations

Denver is located in U.S. Department of Agriculture Plant Hardiness Zone 5, which means winter temperatures may reach minus 20 degrees Fahrenheit. Cool-season grasses and buffalo grass, a native warm-season grass, are recommended for Denver lawns.

Cool Season Grasses

Blends of cool-season grasses contain Kentucky bluegrass and other perennial grasses. Although cool-season grasses also may be seeded in spring, the unpredictability of temperatures makes late summer preferable. Seeding is best completed in August or early September because moisture is retained as temperatures fall.

Buffalo Grass

Buffalo grass is a native, warm-season grass that grows well in clay soil and semi-arid climates, both which are typical in Denver. Because buffalo grass is a native grass, spring seeding with irrigation during any dry spells in May or June is recommended for Denver lawns.

References

• Cooperative Extension System: What is the Growing Season in the Denver Colorado Area?
• USDA: Plant Hardiness Zone Map
• Colorado Gardening: Challenge to Newcomers
• Colorado State University Extension: Seeding a Lawn
• American Lawns: Buffalo Grass