To plant or wait it out? Stine agronomists provide their recommendations.

Planting is underway for a few states in the U.S. The April 3, 2023, Crop Progress Report notes corn planting has started in Texas, North Carolina, Kentucky and Kansas. In Texas, it’s 57% complete, which is slightly above average for this time of year. For the others, the season has just kicked off. In the rest of the U.S., planting is likely a few weeks out or more, especially for growers in the upper Midwest, where states like Minnesota, North Dakota and South Dakota have received persistent heavy snowfall this spring. Regardless of your planting outlook, knowing the right time to hit the field is critical.

“While there are benefits of early planting, you should never rush or you may put your crop at risk early on,” says Bill Kessinger, technical agronomist for Stine. “Issues like imbibitional chilling, uneven emergence or sidewall compaction could limit your crop’s ability to thrive during the growing season. Even if your neighbors have started, take the time to check your soil and the extended forecast to make sure it’s the right time for planting.”

Here are some helpful considerations from our expert agronomy team.   

The benefits of early planting

Beating the summer’s heat is one of the main benefits of planting early. The earlier you plant, the more time your plants will have to emerge and mature before the high temperatures are here to stay.

“This is especially important for corn plants as extreme heat will affect pollination and pollen shed,” says Kessinger.

According to the University of Nebraska Institute of Agriculture and Natural Resources, prolonged periods of heat can reduce pollen production, particularly with consecutive days that reach 95 degrees Fahrenheit or more.

In soybeans, planting early allows the plants to mature at a more optimal time and the soybean canopy to form earlier. Michigan State University Extension suggests, “Early-planted soybeans produce a larger crop canopy earlier in the growing season, which leads to better utilization of the solar radiation and soil moisture available during the growing season.”

After emergence, experts note soybean cotyledons are also more resistant to freezing temperatures than corn as they have thicker tissue.   

The pitfalls of early planting

“For corn, planting into cold, wet soils can increase the risk of uneven emergence,” says Tony Lenz, technical agronomist. “If corn sits in the ground longer than it should, the plant is forced to live off the energy and nutrients stored in the seed, which doesn’t allow for a good start. This can impact the crop during the early vegetative stages and weaken its root structure in the long haul.”

Lenz stresses that growers need to remember corn imbibes 30% of its weight in water before it germinates. “If it imbibes cold moisture within 24-48 hours after planting, it can severely disrupt the germination process, leading to severe issues to the developing embryo. This is called imbibitional chilling, and it can be detrimental to yield,” he adds.

Imbibitional chilling occurs when there’s a dip in the water temperature being imbibed by the seedling, which is why it’s crucial to monitor the extended weather forecast before planting.

“This is especially important to consider with the recent cooler temperatures and heavy moisture we received and are forecast to continue to receive throughout much of the Midwest,” says Lenz. “Imbibational chilling can lead to a corkscrew effect of the mesocotyl, which can result in death of the seedling.” 

Similar to corn, if soybeans are planted in cool, wet soil, they will experience emergence issues. Soybeans are also susceptible to chilling injury.

“Chilling injury compromises the seed coat — or that protective layer — of the soybeans,” says Lenz. “This leads to delay in emergence, or uneven emergence and, ultimately, poor stand. That said, soybeans are a bit better equipped to handle inconsistent emergence compared to corn.”

Other considerations

Growers also need to consult with federal crop insurance guidelines for replanting. According to the University of Minnesota Extension, “Farmers with federal crop insurance will lose replant coverage if they plant before the earliest allowable planting dates specified by the United States Department of Agriculture (USDA) Risk Management Agency.” They add that this is true even if growers need to replant due to factors other than freeze damage or poor emergence. 

Sidewall compaction is another consideration with early planting, especially when seed furrows are made into high-moisture soil.

“Planting into soil that’s too wet can affect emergence and plant stand,” says Kessinger. “If the seed is compacted into wet soils, you run the risk of root growth problems, where the roots might grow sideways versus straight down. The same is true if you plant too shallow. You need to ensure the moisture level of your field is optimal for planting and your planter is adjusted for proper seed-to-soil contact before putting in corn or soybeans.”

The answer to the planting timing conundrum?  

There is no right or wrong answer. It all boils down to your situation and extended forecast. A few things Stine agronomists can always agree on when it comes to planting are:

• Ensure soil temperatures are a consistent 50+ degrees Fahrenheit for more than a few days.
• Check the extended weather forecast and avoid planting when a cold rain is anticipated within 24-48 hours after planting.
• Test your soil moisture. Check the soil at the depth you intend to plant to examine the texture of the soil. Iowa State University Extension and Outreach provides great tips for determining the moisture levels of your soil.
• Avoid sidewall compaction by checking moisture levels, avoiding planting too shallow (we recommend a minimum of 2 to 3 inches for corn and 1.5 to 2 inches for soybeans), and not applying too much downward pressure on the press wheels of your planter.
• Know the date restrictions for federal crop insurance.
• Consult your local Stine agronomist or university extension expert for local recommendations.

To connect with your local Stine agronomist or sales expert for planting recommendations, visit Find Stine. Here’s to a safe and productive planting season!