What happens when your corn crop sustains unwelcome damage from Mother Nature? Learn when your crop is most at risk and what to expect if your crop encounters adverse weather.
Frost damage in corn
The highest risk of frost damage in corn typically occurs in April and October.
Frost damage before V5 is unlikely to significantly impact yield as the growing point is underground until V5. Recovery from frost damage during later corn reproductive stages depends on the extent of leaf damage and the impact on grain quality. Learning to navigate corn harvest and storage after a fall frost can help you preserve yield.
Responding to spring frost damage in corn
If weather cooperates, seedlings can bounce back from spring frost damage without intervention. At 55% to 70% defoliation due to frost, leaving the field to recover on its own is most economical. Past 70% defoliation, replanting is recommended.¹
Will corn dry down after a fall frost?
Fall frosts can reduce storage life unless properly handled, as frost-damaged corn will still dry down, but increased kernel moisture delays the drying period and harvest time. Apparent grain moisture level may be deceiving since the outer part of the kernel dries faster than the interior.
Excessive rainfall and flooding damage to corn
Major rainfall and flooding typically occurs in May and June. The extent of damage largely depends on corn growth stage.
Submerged or saturated fields have the greatest impact on corn from VT through R1, the most critical stages of corn development.² Survival rates increase if the growing point is not completely submerged or if it is submerged for less than 48 hours.³
Temperature, too, impacts survival rates. Over 77 F, plants may not survive as long as 24 hours of flooding.
How to treat flood damage
If flooding occurs prior to emergence and soil surface crusting is present, use a rotary hoe to break the crust layer or cultivate between rows to prompt seedling emergence.
Consider a nitrogen sidedress for corn fields after flooding to address nutrient and nitrogen losses and be aware of harvest tips to reduce damage after flooding.
Hail damage to corn
Early-season hail storms do not typically have a significant yield impact. But a third of all hail storms happen between June and September, when the impact can be severe.
How to treat hail damage in corn
- With severe stalk bruising, harvesting early can help reduce the risk of significant losses from lodging.
- Monitor soil moisture levels to avoid overwatering as defoliation reduces water use.
- Adjust nitrogen inputs. If yield potential is reduced, nitrogen inputs should be reduced.
Wind damage and greensnap in corn
Wind damage can make corn difficult or impossible to harvest. Saturated soils and strong winds can result in lodging. Yield reductions are minimal up until V12 stages but grow more severe in the V13 to V15 stages, with highest yield loss occurring at V17 or later.
The deadliest wind damage to corn is greensnap. Greensnap in corn typically occurs during rapid vegetative growth between the V10 stage and tassel emergence, when stalks are brittle. Plants snapped below the ear are a total loss. Stalks broken above the ear can produce grain.
How to treat corn wind damage
Flattened corn can survive with minimal yield reduction if wind damage occurs early and plants right themselves prior to pollination. If stalks are just bent, not broken, water and nutrient uptake is only slowed. Lodging during later vegetative growth stage can cause unrecoverable damage.
If grain is mature, lodged corn should be harvested first at reduced combine speed, working against the grain of the leaning stalks with gathering snouts as close to the ground as practicality allows. Experts are available to help you make your decisions. Reach out to your seed retailer, a nearby extension office agent or a seed company professional like your regional BASF representative.
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Endnotes
- “Frost - Impact on Early Corn Growth (before V4).” Integrated Crop Management, Iowa State University, crops.extension.iastate.edu/encyclopedia/frost-impact-early-corn-growth-v4. Accessed 7 Sept. 2026.
- “Flooding and Ponding in Corn.” CropWatch, 15 Jan. 2021, cropwatch.unl.edu/2018/flooding-and-ponding-corn. Accessed 7Apr. 2024.
- “Flooding and Ponding in Corn.” CropWatch.
