Kohlrabi, a unique and nutritious member of the brassica family, is gaining popularity among gardeners in Hawaii. This vegetable, known for its mild, sweet flavor and crisp texture, thrives in various climates, making it an excellent choice for the diverse conditions found across the Hawaiian Islands. In this article, we will explore everything you need to know about growing kohlrabi in Hawaii, from selection and planting to care and harvesting.
Before diving into the specifics of cultivation, it’s important to understand what kohlrabi is. Kohlrabi is a cultivar of cabbage (Brassica oleracea) that forms a swollen stem above the ground rather than producing a traditional bulb or root. It can be green or purple in color, with a taste reminiscent of broccoli stems or turnips. Packed with nutrients, it is rich in vitamins C and K and provides dietary fiber.
Hawaii’s tropical climate presents both opportunities and challenges for growing kohlrabi. Kohlrabi prefers cooler temperatures, ideally between 55°F to 75°F (13°C to 24°C). However, with the right techniques, it can be successfully grown in warmer regions.
Kohlrabi thrives in well-draining soil rich in organic material. The ideal soil pH is between 6.0 and 7.0. Before planting, amend your soil with compost or well-rotted manure to enhance its nutrient content and improve drainage.
Kohlrabi requires full sun for optimal growth, which means it should receive at least 6 hours of direct sunlight daily. In areas where temperatures exceed 75°F (24°C), some afternoon shade can help prevent bolting—when plants prematurely produce flowers—instead of growing healthy bulbs.
When choosing kohlrabi varieties to grow in Hawaii, opt for those that are heat-resistant or specifically suited for warmer climates. Popular varieties include:
You can start kohlrabi from seeds or purchase seedlings from local nurseries.
In Hawaii, kohlrabi can be planted year-round due to the mild weather; however, it’s best to aim for two main planting seasons: early spring (March to April) and late summer (September to October). This timing helps avoid the hottest months when plants are more likely to bolt.
If starting with seedlings:
Once your kohlrabi is planted, proper care will ensure robust growth.
Kohlrabi needs consistent moisture, especially during dry periods. Aim to provide one inch of water per week through rainfall or irrigation. However, avoid over-watering as it can lead to root rot.
Feed your kohlrabi with a balanced fertilizer every four weeks after planting. Look for a fertilizer high in nitrogen during the early growth stages to promote leafy growth, followed by a fertilizer higher in potassium once bulbs begin forming.
While kohlrabi is relatively pest-resistant, certain pests such as aphids, cabbage worms, and whiteflies may pose challenges:
Regularly inspect your plants for signs of pests or disease and take action promptly.
Apply organic mulch around your plants to retain moisture, suppress weeds, and regulate soil temperature. Materials such as straw or shredded leaves work well.
Timing your harvest correctly is crucial for maintaining the best flavor and texture of kohlrabi bulbs.
Typically, kohlrabi is ready for harvest within 50-70 days after sowing seeds. The bulbs should be harvested when they reach about 2-4 inches in diameter. If left too long on the plant, they can become woody and tough.
Use a sharp knife or garden shears to cut the bulbs from the stem just below the leaf attachment. Be careful not to damage surrounding plants if you are harvesting multiple bulbs at once.
After harvesting, kohlrabi can be stored for several weeks under proper conditions:
Kohlrabi can be enjoyed raw or cooked:
Its versatility makes it an exciting addition to various dishes ranging from slaws to stir-fries.
Growing kohlrabi in Hawaii offers many rewards—both culinary and nutritional! With its adaptability to different growing conditions across the islands and its unique flavor profile, kohlrabi can easily find its place in any home garden. By following these guidelines on selecting varieties, planting techniques, care requirements, and harvesting practices, you’ll be well on your way to enjoying fresh kohlrabi throughout much of the year. Happy gardening!