How to Grow Corn in Arizona: A Comprehensive Guide

Corn is a staple crop that can thrive in Arizona’s hot, dry climate with the right growing techniques. While Arizona’s desert environment presents challenges, such as intense heat and limited rainfall, it also offers a long growing season ideal for growing certain corn varieties. This guide will cover everything you need to know about growing corn in Arizona, from selecting the right variety to managing the desert conditions for a successful harvest.

1. Understanding Arizona’s Climate

Arizona is located in USDA Hardiness Zones 4b to 10b, depending on the region. Most of the state is characterized by hot summers and mild winters, with desert areas experiencing very high temperatures during summer months. Corn, being a warm-season crop, can grow well in Arizona, but it requires proper timing and irrigation to cope with the heat.

The key to success is planting corn early in the season to take advantage of the cooler temperatures in spring and avoiding the intense heat of late summer.

2. Best Time to Plant Corn in Arizona

In Arizona, the optimal time to plant corn is in early spring, usually from March to April. In cooler areas, you can start planting as early as late February. Corn requires warm soil for germination, and soil temperatures should be at least 50°F to 60°F before planting.

If you miss the spring planting window, you can also plant a second crop in late summer (August), but you’ll need to ensure the corn matures before the first frost in the fall.

3. Choosing the Right Corn Varieties

The key to growing corn in Arizona’s desert conditions is selecting varieties that are heat-tolerant and adapted to shorter growing seasons. Some corn varieties that perform well in Arizona include:

  • Sweet Corn: Popular for home gardens, with varieties like ‘Golden Bantam’ and ‘Silver Queen’ performing well in Arizona’s climate.
  • Dent Corn: This type is more heat-tolerant and is used for flour or animal feed. ‘Hopi Blue’ and ‘Apache Red’ are heirloom varieties traditionally grown by Native American communities in the Southwest.
  • Flint Corn: Grown for decorative or grinding purposes, with varieties like ‘Glass Gem’ known for their vibrant colors and adaptability to dry conditions.

Choose a variety with a shorter growing period (60-90 days) to ensure a successful harvest before the extreme summer heat sets in.

4. Soil Preparation

Corn grows best in rich, well-drained soil with a neutral pH of around 6.0 to 6.8. In Arizona’s desert soils, you may need to amend the soil to improve its nutrient content and water retention.

  • Soil improvement: Add plenty of organic matter like compost or well-rotted manure to improve the soil’s texture and fertility. This will help the soil retain moisture, which is crucial in Arizona’s dry conditions.
  • Fertilization: Corn is a heavy feeder, especially in nitrogen. Before planting, mix a balanced fertilizer, such as a 10-10-10 or 12-12-12, into the soil. You can also side-dress with nitrogen-rich fertilizers as the plants grow.

5. Planting Corn

Corn should be planted directly in the garden rather than started indoors, as it doesn’t transplant well. Follow these steps for planting:

  • Spacing: Plant corn in blocks of short rows, rather than one long row. This helps with wind pollination, which is essential for corn. Space rows 24-36 inches apart, and plant seeds 1-2 inches deep and 8-12 inches apart in each row.
  • Succession planting: To ensure a continuous harvest, you can plant successive blocks of corn every 2-3 weeks during the growing season.

6. Irrigation

Water is critical for growing corn in Arizona, where rainfall is scarce and temperatures soar. Corn needs a consistent water supply, especially during its early growth stages and as the ears begin to develop.

  • Drip irrigation: Drip irrigation is highly recommended for growing corn in Arizona. It helps deliver water directly to the root zone while minimizing evaporation, which is a significant issue in the desert heat.
  • Deep watering: Water corn deeply, providing 1-1.5 inches of water per week. During particularly hot and dry spells, you may need to water more frequently to prevent stress on the plants.
  • Mulching: Apply a layer of mulch around the base of the plants to help retain soil moisture and reduce the soil temperature.

7. Managing the Heat

Even when planting early in the season, Arizona’s spring and early summer temperatures can still climb, causing stress to corn plants. Here are some tips for managing the heat:

  • Shade cloth: If temperatures rise above 95°F, consider using a shade cloth to protect young corn plants from the worst of the afternoon heat.
  • Windbreaks: Corn plants can also be affected by Arizona’s dry winds, which can desiccate the leaves. Planting windbreaks, like sunflowers or using garden netting, can help protect the corn.

8. Fertilizing During Growth

As corn plants grow, they require additional nutrients, particularly nitrogen. Side-dress with a nitrogen-rich fertilizer, such as blood meal or fish emulsion, when the plants are about 12 inches tall and again when they reach knee height (about 24 inches).

9. Pest and Disease Control

Corn in Arizona is generally less prone to some of the diseases that thrive in more humid climates. However, pests can still be an issue.

  • Corn earworms: These pests can damage the developing ears of corn. To prevent them, apply a few drops of vegetable oil to the silks once pollination has occurred.
  • Aphids: If aphids appear on the plants, spraying with a strong jet of water or using insecticidal soap can help keep them in check.
  • Raccoons and birds: These animals love to snack on ripening corn. Consider using netting or fencing to protect your crop.

10. Pollination

Corn is wind-pollinated, so it’s essential to plant in blocks to ensure proper pollination. If corn is not properly pollinated, kernels will not develop fully, leading to poorly formed ears. If you notice poor pollination, you can help the process by gently shaking the plants when the tassels release pollen to ensure it reaches the silks.

11. Harvesting Corn

Corn is usually ready to harvest about 60-100 days after planting, depending on the variety. Here’s how to tell if your corn is ready:

  • Sweet corn: Harvest when the ears are full and the kernels release a milky liquid when punctured with a fingernail. This typically occurs about 20 days after the silks first appear.
  • Dent and flint corn: Wait until the kernels are fully mature and dry on the stalks. The ears should feel firm, and the kernels should have a hard texture.

12. Storing Corn

After harvesting sweet corn, it should be eaten or refrigerated immediately to preserve its sugar content. Dent and flint corn can be stored after drying for several weeks on the stalk or after being harvested and hung in a dry, well-ventilated space.

Conclusion

Growing corn in Arizona may present challenges due to the state’s desert environment, but with careful planning and proper care, you can enjoy a successful crop. By planting early in the season, providing adequate water, and selecting heat-tolerant varieties, you’ll be well on your way to harvesting delicious, homegrown corn from your Arizona garden.