Grape Phenology and GDD accumulation

April 24, 2026 by Jennifer Morganthaler

April 23, 2026

GDD base 50 = 271 . We track GDD at http://agebb.missouri.edu/weather/reports/gddTable.asp and rate the phenology stages according to the Modified E-L System https://door.extension.wisc.edu/files/2010/10/ModifiedEichhornLorennzsystem.pdf

E-L Stage 12 5 Leaves separated; shoots about 10 cm long; inflorescence clear

E-L 12 (4–5 leaves separated)“Grapevine at E-L 12, four to five leaves separated, shoots elongating with visible tendrils and small clusters.” — MVEC Catawba

E-L 12 (4–5 leaves separated)“Grapevine at E-L 12, four to five leaves separated, shoots elongating with visible tendrils and small clusters.” — Genomics Norton Blanc

E-L 12 (4–5 leaves separated)“Grapevine at E-L 12, four to five leaves separated, shoots elongating with visible tendrils and small clusters.” — Foundation Norton Blanc

E-L 12 (4–5 leaves separated)“Grapevine at E-L 12, four to five leaves separated, shoots elongating with visible tendrils and small clusters.” — Demo Concord

E-L Stage 13 6 Leaves separated

E-L 13: Six leaves separated; “Grapevine at E-L 13, with six leaves separated.” — Norton New Winery

E-L 13: Six leaves separated; “Grapevine at E-L 13, with six leaves separated.” — Research Norton

E-L 13: Six leaves separated; “Grapevine at E-L 13, with six leaves separated.” — Genomics Norton

E-L 13: Six leaves separated; “Grapevine at E-L 13, with six leaves separated.” — Foundation Norton

E-L 13: Six leaves separated; “Grapevine at E-L 13, with six leaves separated.” — Genomics CH x CS

E-L 13: Six leaves separated; “Grapevine at E-L 13, with six leaves separated.” — Demo Mars

E-L 13: Six leaves separated; “Grapevine at E-L 13, with six leaves separated.” — Winery Catawba

E-L 13: Six leaves separated; “Grapevine at E-L 13, with six leaves separated.” — Norton New Winery

E-L Stage 14 7 leaves separated

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — North Norton

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — MVEC Sunbelt

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — Genomics J x V

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — Foundation Vignoles

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — Foundation Vidal Blanc

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — Foundation Traminette

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — Research Catawba

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — Foundation Chardonel

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — Foundation Chambourcin

E-L 14: Seven leaves separated; “Grapevine at E-L 14, with seven leaves separated.” — New Winery Chambourcin

E-L Stage 15, shoot elongating rapidly; single flowers in compact groups

E-L 15: Six to seven leaves separated, inflorescences developing — Foundation Vivant

E-L 15: Six to seven leaves separated, inflorescences developing — Foundation Orion

E-L 15: Six to seven leaves separated, inflorescences developing — Foundation Cayuga White

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