How to Grow Kohlrabi in Alaska

Growing kohlrabi, a unique and nutritious member of the cabbage family, can be an exciting endeavor for gardeners in Alaska. With its bulbous stem and crunchy texture, kohlrabi is not only versatile but also rich in vitamins C and K, fiber, and antioxidants. This article will guide you through the process of growing kohlrabi in the challenging Alaskan climate, covering everything from soil preparation to harvesting.

Understanding Kohlrabi

Kohlrabi (Brassica oleracea var. gongylodes) is a cool-season crop that does well in temperate climates. It has two main varieties: green and purple, both of which have similar flavors and culinary uses. This vegetable is particularly well-suited for Alaskan conditions due to its ability to thrive in cooler temperatures and shorter growing seasons.

Choosing the Right Variety

In Alaska, it’s crucial to select kohlrabi varieties that are adapted to shorter growing seasons. Some recommended varieties include:

White Vienna: A popular green variety known for its mild flavor and tender texture.
Purple Vienna: Offers a slightly sweeter taste and vibrant color.
Kossak: A large variety that can yield bigger bulbs.

These varieties not only adapt well to cooler temperatures but also mature quickly, usually within 50 to 70 days.

Soil Preparation

Testing Your Soil

Before planting, it’s essential to test the soil to determine its pH and nutrient levels. Kohlrabi prefers slightly acidic to neutral soil with a pH between 6.0 and 7.0. You can purchase soil test kits from local agricultural extensions or gardening centers.

Amending the Soil

Kohlrabi thrives in rich, well-draining soil. To prepare your garden bed:

Clear the Garden Area: Remove any weeds, rocks, or debris.
Add Organic Matter: Incorporate compost or well-rotted manure into the soil to boost fertility.
Ensure Good Drainage: If your soil retains water, consider raising your planting beds or adding sand and peat moss.

Timing Your Planting

In Alaska’s short growing season, timing is critical. Kohlrabi can be direct-seeded or started indoors:

Indoor Starting

Start Seeds Indoors: Begin sowing seeds indoors about 4-6 weeks before your last expected frost date.
Transplanting: Once seedlings have at least two leaves and outdoor conditions permit (typically when daytime temperatures are around 60°F), harden off your plants before transplanting them outside.

Direct Seeding

For those who prefer direct seeding:

Early Spring Planting: Sow seeds directly into prepared soil approximately 2-4 weeks before the last frost date.
Late Summer Planting: Consider a second planting in late summer for a fall crop, as kohlrabi can tolerate light frosts.

Planting Techniques

When planting kohlrabi, follow these guidelines:

Seed Depth: Sow seeds about ½ inch deep.
Spacing: Space seeds or seedlings about 6-8 inches apart in rows that are 18-24 inches apart to allow for air circulation and growth.
Watering: Water thoroughly after planting to ensure good seed-to-soil contact.

Care During Growth

Watering

Consistent moisture is vital for kohlrabi development. Water deeply once a week, ensuring approximately one inch of water per week. In periods of hot weather or if your soil is sandy, you may need to increase watering frequency.

Fertilization

Kohlrabi benefits from regular fertilization:

Use a balanced fertilizer high in nitrogen during the early growth stage.
Apply compost mid-season to maintain nutrient levels as plants mature.

Weed Control

Weeds compete with kohlrabi for nutrients and water:

Use mulch around your plants to suppress weeds while retaining moisture.
Hand-pulling weeds is effective; be careful not to disturb kohlrabi roots.

Pest Management

Pest control is an important aspect of kohlrabi cultivation:

Common pests include aphids, cabbage worms, and flea beetles. Inspect plants regularly.
Use row covers early in the season to prevent pest infestations.
Encourage beneficial insects like ladybugs that prey on harmful pests.

Disease Prevention

Kohlrabi can be susceptible to diseases such as downy mildew and black rot:

Practice crop rotation each year by planting kohlrabi in different areas of your garden.
Avoid overhead watering to minimize humidity around leaves that can foster fungal diseases.

Harvesting Kohlrabi

Knowing when to harvest kohlrabi is crucial for optimal flavor:

Timing: Harvest when bulbs are about 3-4 inches in diameter for the best taste—usually around 50 to 70 days post-sowing.
Signs of Readiness: Look for firm bulbs; they should feel solid rather than spongy.
How to Harvest: Use a sharp knife or garden shears to cut the bulb off above the root without damaging surrounding plants.

Post-Harvest Handling

After harvesting, it’s essential to handle kohlrabi properly:

Cleaning: Rinse harvested kohlrabi under cool running water to remove any dirt.
Storage: Store in a cool place; ideally at temperatures between 32°F – 40°F with high humidity levels. For long-term storage, you may choose to keep them in the refrigerator’s crisper drawer wrapped in plastic bags or perforated containers.

Culinary Uses of Kohlrabi

Kohlrabi is incredibly versatile in the kitchen:

Raw: Peel and slice it into sticks for snacking or add it to salads for crunch.
Cooked: Steam or sauté it as a side dish; it pairs well with garlic and herbs.
Soups & Stews: Add diced kohlrabi for a nutritious boost.

With its delightful flavor profile and numerous health benefits, incorporating kohlrabi into your diet is an excellent choice!

Conclusion

Growing kohlrabi in Alaska may present some challenges but offers significant rewards in terms of flavor and nutrition. With proper planning, attention to soil health, timely planting, and effective pest management strategies, you can enjoy this unique vegetable right from your garden table. Whether you’re a seasoned gardener or just starting out, kohlrabi can be an exciting addition to your Alaskan gardening adventures!