How to Grow Sweet Corn: A Summer Staple

Are you wondering how to grow sweet corn? You've come to the right place! Whether you're an experienced gardener or just starting out, this guide will provide valuable information on cultivating this delicious summer staple. Sweet corn is a rewarding crop that offers a taste of summer like no other vegetable. Let's dive into the details of growing this warm-season crop in your home garden.

Sweet Corn: When to Plant

Sweet corn is a warm-season crop that thrives in hot weather. Plant your corn after all danger of frost has passed and soil temperatures have reached at least 50°F (10°C). In most regions, this falls between late spring and early summer. You can find your average last frost date online or by contacting your local extension office. If you don't have a soil thermometer, you can use nature's cues: plant corn when apple blossoms begin to fall, when oak leaves are the size of squirrel ears, or when dogwoods are in full bloom.

Sweet Corn: Where and What Variety to Grow

Choose a sunny location for your corn patch. Sweet corn requires full sun, at least 6-8 hours of direct sunlight daily, for optimal growth and ear development. Ensure your soil is well-drained.

There are several varieties of sweet corn to choose from:

• Normal Sugary (SU): Traditional sweet corn varieties with a classic corn flavor and firm, creamy texture. Sugars convert to starch quickly, so eat ASAP.
  • Common varieties: Early Sunglow, Iochief, Silver Queen
• Sugary Enhanced (SE): Sweeter than standard varieties with a longer harvest window. Superior tenderness and good corn flavor.
  • Common varieties: Ambrosia, Bodacious, Kandy Korn, Peaches and Cream
• Supersweet (Sh2): Extra sweet varieties that maintain their sweetness longer after harvest. Crisp texture and slower conversion of sugars to starches.
  • Common varieties: American Dream, Extra Tender, Signature
• Augmented Supersweet Hybrids: All the benefits of Sh2, plus greater vigor and cool soil emergence.
  • Common varieties: Enchanted, Equinox, Inspiration
• Synergistic (Sy): A blend of SE and Sh2 kernels, offering a balance of flavor and sweetness.
  • Common varieties: Allure, Providence, Honey Select
• Quad: The quad varieties offer an old-time heirloom flavor with modern sweetness.
  • Common varieties: Nectar, Temptress

Consider factors like days to maturity and color (yellow, white, or bicolor) when selecting your variety.

Sweet Corn: How to Plant

Plant corn seeds 3/4 to 1 inch deep for early season plantings, and 1-2 inches deep for later plantings. This helps keep them in contact with moist soil as it warms and dries. Space seeds about 4-6 inches apart in rows 30-36 inches apart. For better pollination, plant corn in blocks of at least four short rows rather than one long row. This ensures better pollination as the pollen falls from the tassels to the silks.

Because corn is so tall, extremely high winds can make them lean. If that happens, just leave them alone; some may come back upright. Even if they do not, they will still develop and produce ears.

Sweet Corn: How to Fertilize and Water

Sweet corn is a heavy feeder and requires consistent moisture for optimal growth. Here are some tips:

Fertilizing:

• Before planting, work a balanced fertilizer (like 10-10-10) into the soil.
• When plants are around 12 inches tall, side-dress with a nitrogen-rich fertilizer. We recommend ammonium sulfate, or for organic growers, blood meal.
• Apply another round of nitrogen when tassels first appear.

Watering:

• Provide 1-1.5 inches of water per week through rainfall or irrigation.
• Water deeply and consistently, especially during tasseling, silking, and ear development.
• Use mulch to retain soil moisture and suppress weeds.

Battling Pests and Diseases in Sweet Corn

While sweet corn is one of the easiest crops to grow, and there are very few pests or diseases, here are some issues and how to manage them if they make an appearance.

Pests and Their Management:

• Corn Earworms: This is one of the most common and destructive pests of sweet corn. Use a mixture of white mineral oil (medicinal oil) or a refined mineral oil containing 0.2 percent pyrethrins. Apply the oil using a medicine dropper. One pint of the mixture can treat about 600 ears. Insert the dropper about a quarter inch into the silk mass, just inside the tip of the husk. Apply the treatment 3-7 days after the silk first emerges. This method can protect 75-90% of all ears.
• European Corn Borers: Destroy stalks after harvest and consider Bt (Bacillus thuringiensis) treatments.
• Cutworms: Use protective collars around seedlings or apply diatomaceous earth.

Common Diseases and Treatment:

• Corn Smut: Remove and destroy infected plants. Avoid overwatering and over-fertilizing.
• Common Rust: Use fungicides in early stages if necessary.
• Southern Corn Leaf Blight: Practice crop rotation and maintain good garden hygiene.
• Stewart's Wilt: Choose resistant varieties and control flea beetles, which spread the disease.

Preventive Measures: Practice crop rotation, maintain garden hygiene, and choose disease-resistant varieties when possible. Good weed control also helps prevent disease spread.

Sweet Corn: When to Harvest

Sweet corn is typically ready for harvest 20-30 days after the silk first appears. Look for these signs of readiness:

• Silks have turned brown and dry.
• Kernels are plump and milky when punctured with a fingernail. If the liquid is clear, it’s too early, if there is no liquid, it is past time for harvest.
• Ears feel full and firm when grasped.

To harvest, grasp the ear firmly and pull down, then twist and pull. Process or consume the corn immediately for the best flavor, as sweetness diminishes rapidly after picking.

Shucking Corn: A Step-by-Step Guide

Step-by-Step Instructions:

1. Choose Fresh Ears:
   • Select ears of corn that feel firm and have bright green husks that are tightly wrapped.
   • Look for moist, sticky silk at the top and avoid ears with dry or brown silk.
2. Prepare Your Work Area:
   • Have a large container or trash can nearby to discard the husks and silk.
   • A clean kitchen towel can help in removing stubborn silk strands.
3. Remove the Outer Husks:
   • Hold the ear of corn firmly in one hand.
   • With your other hand, grab the top of the husk and the silk, pulling downwards in one firm motion.
   • Strip away the outer layers of husk until only the inner layers remain.
4. Strip the Inner Husk and Silk:
   • Continue peeling the remaining husk layers down towards the base of the ear.
   • Gather the husk and silk in one hand and pull down completely, exposing the kernels.
   • Repeat on the other side of the ear if necessary.
5. Clean the Corn:
   • Use your hands or a soft brush to remove any lingering silk strands from the kernels.
   • If necessary, run the corn under cool water to help remove any remaining silk.
6. Trim the Ends:
   • Use a sharp knife to cut off the stem end of the corn, making it easier to handle and cook.

Tips for Easier Shucking:

• Microwave Method: Place the entire ear of corn (with husk intact) in the microwave for 1-2 minutes. The heat will make the husks easier to remove.
• Boiling Method: Boil the corn with the husk on for 2-3 minutes, then remove and let cool slightly before shucking. This method loosens the husk and silk.
• Preventing Silk Stickiness: After removing the bulk of the silk by hand, dampen a paper towel and rub it along the kernels to catch any remaining strands.

Storing Shucked Corn:

• Refrigeration: Store shucked corn in a plastic bag in the refrigerator for up to a week. The sooner you use it, the sweeter it will taste.
• Freezing: If you plan to freeze corn, blanch the shucked ears in boiling water for 4-6 minutes, then cool in ice water. Pat dry, cut the kernels off the cob, and freeze in airtight bags.

Fresh Eating Ideas: Sweet Corn Recipes

1. Grilled Sweet Corn with Herb Butter

Ingredients:

• 6 ears of sweet corn, husked
• 1/2 cup unsalted butter, softened
• 1 tbsp fresh parsley, chopped
• 1 tbsp fresh chives, chopped
• 1 tsp fresh thyme, chopped
• Salt and pepper to taste

Instructions:

1. Preheat your grill to medium-high heat.
2. In a small bowl, mix the butter with the chopped herbs, salt, and pepper.
3. Spread the herb butter evenly over the corn.
4. Grill the corn for 10-12 minutes, turning occasionally, until the kernels are tender and slightly charred.
5. Serve hot, with extra herb butter on the side if desired.

2. Sweet Corn and Tomato Salad

3. Creamy Sweet Corn Soup

Ingredients:

• 6 ears of sweet corn, kernels cut off the cob
• 1 medium onion, chopped
• 2 cloves garlic, minced
• 3 cups vegetable broth
• 1 cup heavy cream
• 2 tbsp butter
• Salt and pepper to taste
• Fresh chives, chopped, for garnish

Instructions:

1. In a large pot, melt the butter over medium heat.
2. Add the onion and garlic, sauté until softened, about 5 minutes.
3. Add the corn kernels and vegetable broth, bring to a boil.
4. Reduce heat and simmer for 15-20 minutes, until the corn is tender.
5. Use an immersion blender to puree the soup until smooth. Alternatively, transfer the soup to a blender in batches and blend until smooth.
6. Stir in the heavy cream, salt, and pepper.
7. Heat through but do not boil.
8. Serve hot, garnished with fresh chives.

Preserving Your Sweet Corn Harvest

Storing Fresh Sweet Corn:

• Keep unhusked ears in the refrigerator for up to a week.
• For the best flavor, consume within 1-2 days of harvest.

Freezing:

• Blanch ears or cut kernels before freezing.
• Properly frozen corn can last up to 12 months.

Canning:

• Use a pressure canner for safe preservation.
• Follow USDA guidelines for proper canning procedures.

Drying:

• While less common, corn can be dried for long-term storage or to make corn flour.

The Dietary Benefits of Sweet Corn

Sweet corn is not only delicious but also nutritious. It's a good source of fiber, vitamins (particularly B vitamins like thiamin and niacin), and minerals like magnesium and potassium. It also contains antioxidants, including lutein and zeaxanthin, which are beneficial for eye health. The insoluble fiber in corn helps promote a healthy gut and regular bowel movements.

While corn does contain some protein, it's an incomplete protein lacking some essential amino acids. However, when combined with other protein sources like beans, it creates a complete protein and increases the overall health benefits.

How to Grow Sweet Corn with Companion Plants

Good companions for sweet corn include:

• Beans: They fix nitrogen in the soil, benefiting corn.
• Squash: Provides ground cover, reducing weeds and retaining soil moisture. These vines also keep raccoons from raiding your corn patch!
• Cucumbers: Can be trained up corn stalks for support.

Avoid planting tomatoes near corn, as they can attract the same pests.

Isolating Different Corn Varieties:

When growing more than one variety, it's necessary to isolate plantings to prevent cross-pollination, which can lead to starchy, tough corn. You can isolate by time or distance:

• Time: Plant varieties so their maturation times are at least two weeks apart.
• Distance: Separate varieties, especially Supersweet (Sh2) types, by at least 350 feet from other corn types.

Here's to growing the sweetest, most flavorful corn in your home garden!