Kohlrabi, a unique and versatile vegetable, has been gaining popularity among home gardeners and chefs alike. Known for its crunchy texture and mildly sweet flavor, this member of the Brassica family, which also includes cabbage, broccoli, and kale, is a cool-season crop that thrives in the climatic conditions of Illinois. If you’re interested in adding this nutritious vegetable to your garden, follow this comprehensive guide on how to grow kohlrabi in Illinois.
Understanding Kohlrabi
Before diving into the growing process, it’s essential to understand what kohlrabi is. This vegetable has a swollen stem that grows above the ground, resembling a turnip or a bulbous root vegetable. It comes in two varieties: green and purple, both offering similar flavors and nutritional benefits. Kohlrabi is rich in vitamins C and K, fiber, and antioxidants, making it an excellent addition to a healthy diet.
Choosing the Right Variety
Selecting the right variety of kohlrabi is crucial for success in your Illinois garden. The common varieties include:
- Green Kohlrabi: This variety is popular for its tender texture and sweet flavor. It is usually ready for harvest quicker than purple kohlrabi.
- Purple Kohlrabi: Known for its vibrant color, it has a slightly stronger flavor but is equally delicious when harvested young.
Consider your cooking preferences and aesthetic desires when choosing your variety.
Ideal Growing Conditions
Soil Requirements
Kohlrabi thrives best in well-draining soil enriched with organic matter. The ideal soil pH ranges from 6.0 to 7.0. To prepare your soil:
- Test the Soil: Use a soil test kit to determine pH levels and nutrient content.
- Amend with Organic Matter: Incorporate compost or well-rotted manure to improve soil fertility and structure.
- Tillage: Till the soil to a depth of at least 12 inches to ensure proper aeration.
Light Requirements
Kohlrabi prefers full sun but can tolerate partial shade. Aim for at least 6 hours of direct sunlight daily for optimal growth.
Temperature Preferences
As a cool-season crop, kohlrabi thrives in temperatures ranging from 60°F to 75°F. In Illinois, you can plant kohlrabi in early spring for a summer harvest or late summer for a fall harvest.
Planting Kohlrabi
When to Plant
Timing is crucial when planting kohlrabi in Illinois:
- Spring Planting: Sow seeds outdoors about 2-4 weeks before the last expected frost date (typically mid-April to early May in most parts of Illinois).
- Fall Planting: For a fall harvest, sow seeds indoors 6-8 weeks before the first expected frost (usually early August).
Seed Sowing Techniques
You can start kohlrabi seeds indoors or directly sow them in the garden:
- Indoor Sowing: Use seed trays filled with seed-starting mix. Plant seeds about ¼ inch deep and keep them moist. Transplant seedlings outdoors when they are about 3-4 inches tall.
- Direct Sowing: Make rows approximately 12 inches apart, planting seeds about ½ inch deep and spacing them 6-8 inches apart within the row.
Thinning Seedlings
Once seedlings have grown to about 2 inches tall, thin them out to avoid overcrowding. Leave only the strongest plants spaced 6-8 inches apart to allow sufficient room for growth.
Caring for Kohlrabi
Watering
Kohlrabi requires consistent moisture for optimal growth. Aim to provide about 1 inch of water per week, either through rainfall or irrigation. Deep watering is better than frequent shallow watering; ensure that water reaches at least 6 inches into the soil.
Fertilizing
For rich growth, apply a balanced fertilizer (10-10-10) at planting time according to package instructions. You may also consider side-dressing with additional compost or organic fertilizer halfway through the growing season.
Weeding
Keep your kohlrabi bed free from weeds that compete for nutrients and water. Hand-pulling weeds is effective; alternatively, use mulch around the plants to suppress weed growth while conserving moisture.
Pest and Disease Management
Kohlrabi may face threats from pests such as aphids, cabbage worms, and flea beetles. Employ these strategies for effective management:
- Row Covers: Use floating row covers during early growth stages to protect seedlings from pests.
- Natural Predators: Encourage beneficial insects like ladybugs that feed on aphids.
- Crop Rotation: Avoid planting kohlrabi (and other Brassicas) in the same spot year after year to reduce pest buildup.
Common diseases include downy mildew and clubroot; however, maintaining good air circulation through proper spacing can help prevent issues.
Harvesting Kohlrabi
The ideal time to harvest kohlrabi is when bulbs reach about 3–4 inches in diameter—typically around 50–70 days after sowing seeds depending on the variety. For best flavor and tenderness, harvest kohlrabi when they are young; if left too long, they may become woody.
To harvest:
- Use a sharp knife or garden shears.
- Cut the bulb just above the ground level.
- Remove any foliage that is wilted or damaged but save healthy leaves—they are also edible!
Storing Kohlrabi
Freshly harvested kohlrabi can be stored for several weeks under ideal conditions:
- Refrigeration: Place unwashed bulbs in plastic bags with holes (to allow air circulation) and store them in the vegetable crisper drawer of your refrigerator.
- Remove Leaves: Cut off leaves before storage as they can draw moisture from the bulbs.
Kohlrabi can also be blanched and frozen if you wish to store it long-term; however, fresh consumption offers superior flavor and nutritional value.
Conclusion
Growing kohlrabi in Illinois can be an enjoyable experience that yields delicious results whether you’re looking to enhance your culinary repertoire or simply want fresh vegetables from your backyard garden. By following this guide on planting techniques, care requirements, pest management, harvesting tips, and storage methods, you’ll be well on your way to enjoying this unique vegetable throughout its growing season—whether fresh in salads or cooked into hearty dishes! Embrace this opportunity to diversify your home garden with kohlrabi and relish the rewards it brings!