Grower Degree Days Calculator

Grower Degree Days is a heat index calculation that helps growers determine all sorts of useful information: Bud swell, leaf emergence, flowers, and pest emergence to name a few.

In the nursery industry this gives us an opportunity to better plan and be successful with our pest management plans. Insects and mites are cold blooded, so they rely on certain thresholds of temperature for them to become active.

Grower Degree Days Calculator

Full GGD Calendar

GDD ----
High/Low--°F / --°F

The Basic Way to Calculate Degree Days Is This

Using this equation will give you the number of degree days you accumulated for your area each day. This can be done every day to give you a running total for the year.


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Goodmark Nurseries, LLC

8920 Howe Road
Wonder Lake, IL 60097
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South Branch Farm

18101 Route 176
Union, IL 60180
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Fax: 815-728-0977