Lawn Care: Grass Growing Temperature Guide

Table of Contents

• Grass Growing Temperatures
  • Cool Season Grasses
  • Warm Season Grasses

Grass Growing Temperatures

A report published by the North Carolina State University Turf Council (“Soil Temperature Reports Aid Managers” March 31, 2005) shows the impact of soil temperature on cool and warm season turf. Knowing where you are at in this range should help you understand how bad your turf is hurting right now.

Cool Season Grasses

Temperature (°F)	Biological Event
90	Shoot growth ceases.
77	Root growth ceases.
70	Maximum temperature for root growth of any consequence.
70	Time to plant grasses in late summer.
60–75	Optimum temperature for shoot growth.
50–65	Optimum temperature for root growth.
40	Shoot growth ceases.
33	Root growth ceases.
20	Low temperature kill possible if temperature subsequently drops rapidly below 20°F.

Warm Season Grasses

Temperature (°F)	Biological Event
120	Shoot growth ceases.
110	Root growth ceases.
80–90	Optimum shoot growth.
75–85	Optimum root growth.
74	Optimum time to overseed bermudagrass with ryegrass in the fall. Time to plant grasses in the spring.
64	Expected spring root decline is triggered and roots turn brown and die within 1 or 2 days.
50	Root growth begins to slow below this temperature.
50	Chilling injury resulting in discoloration is possible.
50	Initiation of dormancy occurs resulting in discoloration.
25	Low temperature kill possible.