Growing Degree Day (GDD)
Years ago, a Growing Degree Day (GDD) article was a reoccuring staple in what was the weekly Buckeye Yard and Garden Line (BYGL) e-newsletter. While the newsletter evolved into a real time, blog-like, format, GDD information still had a presence as an occasional summary and of course was included in many of the insect alerts. In 2022, you wiill be seeing monthly summaries, and we will continue to tie in GDDs into other alerts as well.
As you can expect, January starts out pretty slow. In fact, 4 of the 20 Ohio zip codes that were chosen across Ohio to give you a flavor of what is happening accross the buckeye state, haven't accumulated a single GDD unit as of the end of the month.
GGD Chart, January 31, 2022
Ohio City (County)Zip Code GDD Unit Accumulation
Van Wert (Van Wert)
Mt. Gilead (Morrow)
Mt. Vernon (Knox)
GGD Species List (Common Name, Scientific Name, Phenological Event, GDD)
The list includes both plants and insects. Insects are bolded within the list.
Silver Maple, Acer saccharinum, first bloom, 34; Corneliancherry Dogwood, Cornus mas, first bloom, 40; Silver Maple, Acer saccharinum, full floom, 42; Red Maple, Acer rubrum, first bloom, 44; Speckled Alder, Alnus incaca spp.,rugosa, first bloom, 52; Northern Lights Forsythia, Forsythia x intermedia, first bloom, 58; Japanese Pieris, Pieris japonica, first bloom, 60; Red Maple, Acer rubrum, full bloom, 75; Star Magnolia, Magnolia stella, first bloom, 83; White Pine Weevil, Pissodes strobi, adult emergence, 84; Border Forsythia, Forsythia x intermedia, first bloom, 86; Eastern Tent Caterpillar, Malacosoma americanum, egg hatch, 92; Manchu Cherry, Prunus tomentosa, first bloom, 93; Northern Lights Forsythia, Forsythia x intermedia, full bloom, 94; Speckled Alder, Alnus incana, full bloom, 97; Corneliancherry Dogwood, Cornus mas, full bloom, 98; Norway Maple, Acer plantanoides, first bloom, 116; Border Forsythia, Forsythia x intermedia, full bloom, 116.
As you can see, although accumulations have begun, the units thus far fall beneath the start of the species list that begins with Silver Maple. Progression can be slow and lethargical, but as temperatures rise, GDD unit accumulations rise and we will be off to the races!
If this is your first explosure to Growing Degree Days and you want to learn more, check out these past BYGL Alerts, Word of the Week - Growing Degree Days: https://bygl.osu.edu/index.php/node/1753; and Growing Degree Days (GDD) - What's Your Number?: https://bygl.osu.edu/index.php/node/1448
Stay tuned at the beginning of each month for the previous month's summary.
OSU Growing Degree Day Website