Turfgrass Seed Management – How Long Grass Will Take To Germinate In The Spring – 2009 11 00

 

 

November 2009, Volume 12, Issue 5
Jacklin Seed Research News Flash
Selected and adapted excerpts

 

Is there some way of predicting how long grass will take to germinate in the spring, especially when temperatures are cold ?

There are a few research studies that address this issue, mainly by Danish authors.

An article by Søren Ugilt Larsen and Bo Martin Bibby allows you to predict when in the spring Kentucky bluegrass will germinate, given daily air temperature.

The trick is to keep a running tally of all the daily maximum temperatures above 2.6°C ( or 37°F ).

If you take your daily high, subtract 2.6 °C ( or 37°F ), your Kentucky bluegrass will reach 50 per cent germination when the running sum exceeds 115°C ( 207°F ) cumulative degrees.

Thermal time for perennial ryegrass is 63.9 C ( 115°F ), and 43.8°C ( 79°F ) for red fescue.

An older but still relevant article comes from a 1940 USGA publication by Aubrey W. Naylor.

Naylor explains that mature Kentucky bluegrass grows in the spring long before its seed would germinate.

Bluegrass  ―  when well-established, grows most vigorously at temperatures between 60° and 75°F.

Kentucky bluegrass, once it has become established, will grow well under conditions which are unfavorable for the germination of its seed and for early growth.

 

 

 

Classification Of Turfgrasses According To Their
Seed Characteristics

 

Turfgrass species

Seed germination rate
under optimal conditions

Seed establishment rate
under optimal conditions

Optimal germination
temperatures

 

 

 

 

Annual bluegrass

 

Moderately fast
10 to 20 growing days

Moderately slow
3 to 4 growing months

20 to 30°C

Annual ryegrass

 

Very fast
3 to 5 growing days

Very fast
½ to ¾ growing month

20 to 30°C
Pre-chill 3 to 10°C

Canada bluegrass

 

Moderately slow
15 to 30 growing days

Slow
4 to 6 growing months

Chewings fescue

 

Moderately fast
10 to 20 growing days

Moderately fast
2 to 4 growing months

20 to 25°C
Pre-chill 3 to 10°C

Colonial bentgrass

 

Moderately fast
10 to 20 growing days

Moderately slow
3 to 4 growing months

15 to 30°C
Pre-chill 3 to 10°C

Creeping bentgrass

 

Fast
5 to 10 growing days

Moderately slow
3 to 4 growing months

15 to 30°C
Pre-chill 3 to 10°C

Creeping bluegrass

 

Fast
5 to 10 growing days

Moderately slow
3 to 4 growing months

Hard fescue

 

Moderately fast
10 to 20 growing days

Moderately fast
2 to 4 growing months

Kentucky bluegrass,
most cultivars

Moderately slow
15 to 30 growing days

Slow
4 to 6 growing months

 

15 to 30°C
Pre-chill 3 to 10°C

Kentucky bluegrass,
some cultivars

Moderately fast
10 to 20 growing days

Perennial ryegrass

 

Fast
5 to 10 growing days

Fast
App 1 growing month

20 to 30°C
Pre-chill 3 to 10°C

Red fescue

 

Moderately fast
10 to 20 growing days

Moderately fast
2 to 4 growing months

15 to 30°C
Pre-chill 3 to 10°C

Red top

 

Moderately fast
10 to 20 growing days

Fast
App 1 growing month

20 to 30°C

Rough bluegrass

 

Moderately slow
15 to 30 growing days

Slow
4 to 6 growing months

20 to 30°C
Pre-chill 3 to 10°C

Sheep fescue

 

Moderately fast
10 to 20 growing days

Moderately fast
2 to 4 growing months

Tall fescue

 

Moderately fast
10 to 20 growing days

Moderately fast
2 to 4 growing months

20 to 30°C

 

Establishment rates are an estimated measure of the time required for seedlings to develop, under optimal conditions, into mature and healthy plants that are « ready-for-use ».  The optimal conditions for the seed germination of most species may not require a single temperature, but a rhythmic alternation of temperature.  In the above table, the first number indicates the initial temperature that must be maintained for approximately sixteen hours.  The second number indicates the following temperature that must be maintained for approximately eight hours.  ( Beard, 1973 )

 

 

 

For a copy of the original A Look At Report, go to the following link  …

http://pesticidetruths.com/wp-content/uploads/2011/11/Force-Of-Nature-A-Look-At-Seed-2009-11-00-How-Long-Grass-Will-Take-To-Germinate-In-The-Spring-pdf-300-dpi.pdf

 

NORAHG has archived more information about TURF & ORNAMENTALS, and other topics, on The Pesticide Truths Web-Site  …

 

A LOOK AT  …  REFERENCES & SLIDE SHOWS  –  TURF, ORNAMENTALS, ENVIRONMENT, & MAINTENANCE

http://pesticidetruths.com/toc/a-look-at-references-turf-ornamentals/

 

A LOOK AT  …  REPORTS  –  TURF, ORNAMENTALS, & MAINTENANCE

http://pesticidetruths.com/toc/a-look-at-reports/

 

A LOOK AT  …  CAREER MANAGEMENT

http://pesticidetruths.com/toc/a-look-at-career-management/

 

UPDATES & WARNINGS

http://pesticidetruths.com/toc/updates-warning/

 

THE WISDOM OF ART C. DRYSDALE

http://pesticidetruths.com/toc/the-wisdom-of-art-c-drysdale/

 

 

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