Ontario, Canada / Corn (Essex)

Total GDD: 2823 (Oct 31)

Day 184 / 184 (100%)

Current Season

Total GDD: 2823 (Oct 31)

Method: 50°F | 86°F max

7-Day Daily Avg: 0.0

7-Day Projection: 2823 by Nov 07

Season: May 01, 25 - Oct 31, 2025

Key Freeze Dates (28°F)

Last Freeze:
10%: 03-30
50%: 04-09
90%: 04-29

First Freeze:
10%: 10-27
50%: 11-06
90%: 11-16

Growing Degree Days (GDD) track heat accumulation to predict when plants reach growth stages, pests emerge, and diseases become active.

Thresholds mark specific GDD values when events typically occur, with crossing dates showing when your season reaches each milestone.

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Thresholds & Notes

Emergence (VE) 120 °D

May 17, 2025 | May 14, 2024 | May 20, 2023 | May 16, 2022

Growth Stage

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Coleoptile visible. Scout for seedling diseases in heavy Essex County soils.

Rapid Growth (V6) 525 °D

Jun 20, 2025 | Jun 9, 2024 | Jun 20, 2023 | Jun 12, 2022

Growth Stage

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Growing point above soil. Side-dress nitrogen window for Ontario corn.

Tassel Initiation (V12) 975 °D

Jul 6, 2025 | Jun 30, 2024 | Jul 11, 2023 | Jul 3, 2022

Growth Stage

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Ear size determined. Critical drought stress period begins.

Tasseling (VT) 1250 °D

Jul 17, 2025 | Jul 12, 2024 | Jul 25, 2023 | Jul 16, 2022

Growth Stage

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Tassel fully emerged. Western bean cutworm monitoring Chatham-Kent region.

Silking (R1) 1400 °D

Jul 24, 2025 | Jul 19, 2024 | Jul 31, 2023 | Jul 22, 2022

Growth Stage

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Silks visible. Peak water demand ~0.35"/day. Irrigation critical if available.

Blister (R2) 1600 °D

Aug 2, 2025 | Jul 29, 2024 | Aug 10, 2023 | Jul 31, 2022

Growth Stage

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Kernels white, blister-like. Stalk integrity scouting begins.

Milk (R3) 1900 °D

Aug 14, 2025 | Aug 10, 2024 | Aug 26, 2023 | Aug 13, 2022

Growth Stage

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Milky kernel fluid. Corn ear worm scouting threshold.

Dough (R4) 2200 °D

Sep 2, 2025 | Aug 27, 2024 | Sep 15, 2023 | Aug 29, 2022

Growth Stage

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Pasty starch consistency. 50% dry matter accumulation reached.

Dent (R5) 2500 °D

Sep 23, 2025 | Sep 14, 2024 | Oct 19, 2023 | Sep 13, 2022

Growth Stage

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Kernel denting visible. Black layer forming begins.

Physiological Maturity (R6) 2850 °D

Oct 6, 2024

Growth Stage

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Black layer complete. ~30-32% grain moisture. Safe from frost damage.