Agricultural Seasonality: Corn, Soybeans, and Wheat Calendar Patterns

Grain markets run on a fixed biological calendar. Planting, pollination, and harvest create recurring supply-and-demand rhythms that produce statistically reliable seasonal windows. The edge isn't in trading every seasonal — it's in stacking the four or five highest-odds windows per year.

Corn (ZC)

• March–May planting rally. Wet or delayed planting pulls yield forecasts; corn historically rises 8–15% from late March to the July WASDE report. Long bias April 1 to June 15.
• July–August pollination risk. Heat above 95°F during pollination cuts yields. This is a volatility event, not a directional bet — own options, not futures.
• September–October harvest low. New supply hits the market; corn typically bottoms late September, down 6–12% from the summer high. Cover longs by October 1.

Soybeans (ZS)

• June–August weather scare. The July–August pod-set window is the most volatile; soybean implied vol jumps from 18% to 35%+. Long straddles entering June capture the move.
• November–January South America flip. Brazilian planting delays lift US beans; the Nov-to-Jan window historically rises 5–9%.

Wheat (ZW)

• January–February freeze risk. Winter wheat in the US Plains and Black Sea can freeze; January longs have worked in 7 of the last 10 years.
• June–July harvest pressure. Wheat drops 5–10% into the US winter wheat harvest; short or stand aside July.

Rules to avoid false seasonals

• Confirm with WASDE and Crop Progress reports — never trade a seasonal blindly against a bearish USDA surprise.
• Require confluence: seasonal window + technical support/resistance + correct carry structure (backwardation for longs).
• Cap risk at 1.5% per seasonal trade; weather can break the pattern any given year.
• Sample size matters. A seasonal that worked 6 of 10 years is barely above random; demand 7 of 10 with a defined fundamental driver.

Skip seasonals during years with structural regime shifts — a 2022-style Black Sea war distorts wheat seasonals beyond use.