Ornamental grasses are classified as warm season, cool season or tender perennial. They are at their best at different times of the year and require slightly different care, depending on their classification.

Cool Season Grasses, What are They?

Cool season grasses are those that are at their most active growth during the cool season. Growth begins in the fall and often these grasses are the first to flower in the spring garden. As the summer heats up, cool season grasses go into dormancy to begin the cycle again in fall.

Most fescues and carex varieties are popular cool season choices

Cool Season Grasses

  • Actively grow between temperatures above freezing and up to mid 20’s degrees Celsius.
  • Are mostly evergreen (a few are deciduous).
  • Are mostly low growers, 2 feet maximum height.
  • Mostly flower late winter to early summer.

Warm Season Grasses, What are They?

As you can expect, warm season grasses are those that are at their most active during the warmest months of the year.  Growth begins as the spring sunshine heats the soil. The plant grows and flowers during the warm summer months and enters dormancy as winter approaches. The sun-bleached remnants of the season's growth make for wonderful winter interest and are attractive to birds and small animals.

Sun-bleached foliage and seedheads create winter drama in a usually bleak landscape

Warm Season Grasses:

  • Need warm soil conditions to get growing in the spring.
  • Grow best when temperatures are above 24 degrees Celsius.
  • Die back to dormant buds beneath the soil surface in the fall (perennial).
  • Mostly taller growers, 2-8 feet but some as high as 15 feet.
  • Start flowering mid-summer to first frost