When To Plant Corn In Oklahoma

Knowing when to plant corn in Oklahoma is the single most important factor for a successful harvest. Get the timing right, and you set the stage for strong, productive stalks that can handle our unique climate.

Plant too early, and a late frost can wipe out your seedlings. Plant to late, and the summer heat will stress the plants during pollination. This guide will walk you through the optimal windows, variety selection, and tips to align your planting with Oklahoma’s weather patterns.

The best time to plant corn in Oklahoma depends heavily on your specific region within the state. Soil temperature is a more reliable guide than calendar dates alone.

You should aim for a soil temperature at planting depth of at least 50°F. For optimal and rapid germination, wait until the soil is consistently 55-60°F. You can measure this with a simple soil thermometer.

Oklahoma’s Regional Planting Windows

Oklahoma’s climate varies significantly from the panhandle to the southeast. Here’s a general breakdown:

Central & Eastern Oklahoma: The prime window is typically from late March through mid-April. The warmer soils in the Red River valley allow for some of the earliest plantings.
Western Oklahoma & Panhandle: Here, you should wait until mid-April to early May. Frost risk persists longer, and soils warm up more slowly.
Statewide Rule of Thumb: A traditional guideline is to plant corn after the average last spring frost date for your area. For many, this falls around April 5-15.

Why Timing is Everything for Pollination

Your planting date directly controls when your corn will pollinate. This is critical.

Corn pollinates best when daytime temperatures are between 86°F and 90°F, with adequate soil moisture. If you plant so that pollination occurs during the peak of Oklahoma’s July heat (above 95°F) or during a typical dry spell, kernel set will be poor.

The goal is to have the corn tasseling and silking before the most intense summer stress hits. A well-timed crop will also be more likely to mature before early fall frosts in northern counties.

Choosing the Right Corn Variety

Your choice of variety must match your planting date and location. The “Days to Maturity” on the seed packet is key.

Full-Season Varieties (110+ days): Plant these as early as safely possible in the spring. They need the longest growing season and are best for central and eastern regions.
Mid-Season Varieties (90-110 days): A versatile choice for most gardeners. They offer a good balance of yield and flexibility on planting date.
Short-Season Varieties (70-90 days): Ideal for western Oklahoma, double-cropping, or if you got a late start. They mature faster but often have slightly lower yield potential.

Consider Hybrid vs. Heirloom

Many Oklahoma gardeners prefer modern hybrids for there improved drought tolerance, heat resistance, and disease resistance. Heirlooms offer unique flavors but may be less reliable in tough conditions.

Step-by-Step Planting Guide

Soil Preparation: Corn needs deep, well-drained soil with plenty of organic matter. Work in compost or aged manure in the fall or early spring. Aim for a soil pH between 6.0 and 6.8.
Planting Depth & Spacing: Plant seeds 1.5 to 2 inches deep. Space seeds 8-12 inches apart within rows, with rows 30-36 inches apart. Corn is wind-pollinated, so plant in blocks of at least 4 rows rather than one long single row for good pollination.
Fertilizing at Planting: Use a balanced starter fertilizer low in nitrogen but with phosphorus to encourage root growth. Side-dress with a high-nitrogen fertilizer when plants are about knee-high.
Watering Schedule: Provide 1-1.5 inches of water per week. The most critical periods are during tasseling, silking, and ear development. Deep, infrequent watering is better than frequent light sprinklings.

Common Mistakes to Avoid

Even experienced gardeners can make errors with corn timing. Here’s what to watch for:

Planting in Cold, Wet Soil: Seeds will rot or germinate poorly. Patience is vital.
Ignoring Soil Tests: Corn is a heavy feeder. A soil test tells you exactly what nutrients you need to add.
Overcrowding: Plants that are to close together compete for light and nutrients, leading to smaller ears.
Missing the Pest Window: Be prepared for corn earworms and borers. Monitor plants closely and use appropriate controls before infestation gets severe.

Planning for Succession & Fall Harvest

For a continuous harvest, you can plant early, mid, and late-season varieties at the same time. Alternatively, plant the same variety 10-14 days apart.

For a fall harvest, you need to work backwards from your average first fall frost. Choose a variety whose “Days to Maturity” fits within the number of days between your late-summer planting date and the expected frost. This is tricky in Oklahoma due to fall heat, but can be done with careful watering.

Signs Your Corn is Ready for Harvest

Harvest typically comes 18-24 days after silks appear. Look for these signs:

Silks have turned brown and dry.
The ear feels firm and full.
Kernels exude a milky, not clear, liquid when pierced.

FAQ: Planting Corn in Oklahoma

What is the absolute last date to plant corn in Oklahoma?

This varies, but a general cutoff is late June to early July for central regions, using a very short-season variety. However, yields diminish significantly with late plantings due to heat stress.

Can I plant corn in July?

For a fall crop, yes, but it’s risky. You must use a short-season variety (70-80 days) and be prepared to irrigate consistently. Pest pressure is also often higher.

How do I protect young corn from a late frost?

If seedlings are emerged and a frost is forecast, cover them with row cover, frost cloth, or even cardboard boxes overnight. Remove covers during the day.

Is it better to start corn indoors?

Corn transplants poorly due to its root system. It’s almost always better to direct-seed into the garden at the proper time.

What are good companion plants for Oklahoma corn?

Beans and squash are classic companions. Beans fix nitrogen, and squash leaves shade the soil, reducing weeds and moisture loss. Avoid planting near tomatoes.

By aligning your planting date with soil temperature, regional weather, and the right corn variety, you give your garden the best chance for a bountiful harvest. Keep a garden journal each year noting your planting dates and the results—this is your most valuable tool for refining your timing season after season.