Avoiding Woody Texture
Woody kohlrabi is one of the most common problems gardeners face. A fibrous, tough texture can make this otherwise delightful vegetable less enjoyable. Preventing woody kohlrabi starts with understanding the causes, primarily environmental stress and delayed harvesting.
Selecting the Right Variety
Choose varieties bred for tenderness and flavor, such as 'Early Purple Vienna' or 'Winner', which are known for their ability to stay tender under various conditions. These varieties are excellent options for both spring and fall planting.
Optimal Growing Conditions
Kohlrabi thrives in temperatures between 40°F and 75°F. High heat or sudden fluctuations in weather can stress the plant, leading to tougher bulbs. Plan your planting dates carefully, aiming for early spring or late summer to avoid extreme weather. Use row covers during sudden cold snaps or heat waves to protect your crop.
Soil Preparation
A well-prepared soil rich in organic matter is key. Work in plenty of compost or well-aged manure before planting to ensure a fertile and well-draining growing medium. Soil pH between 6.0 and 7.5 is ideal for reducing plant stress and promoting tender growth.
Maintaining Consistent Watering
Inconsistent watering can negatively affect kohlrabi taste and texture, often resulting in cracked, woody, or bitter bulbs. Maintaining consistent moisture levels is critical to growing sweet kohlrabi.
Watering Techniques
Water deeply and consistently, providing about 1–1.5 inches of water per week. Drip irrigation systems or soaker hoses are excellent options for maintaining even soil moisture. These methods also reduce water waste and minimize the risk of fungal diseases.
Mulching to Retain Moisture
Apply a 2–3 inch layer of organic mulch, such as straw or shredded leaves, around the base of your plants. Mulch helps retain soil moisture, regulate temperature, and prevent weeds, all of which contribute to healthy kohlrabi.
Avoid Waterlogging
While consistent watering is important, avoid overwatering, which can lead to root rot and other diseases. Ensure your soil has good drainage to prevent water from pooling around the plants.
Harvesting at the Right Time
Harvesting kohlrabi at the right stage of maturity is essential for achieving the best flavor and texture. Bulbs that stay in the ground too long tend to become woody and lose their sweetness.
When to Harvest
Kohlrabi is typically ready to harvest when the bulb reaches 2–3 inches in diameter, about the size of a tennis ball. At this stage, the bulbs are tender and flavorful. Some larger varieties, such as 'Kossak', can grow up to 5 inches in diameter without losing quality, but check the seed packet for specific recommendations.
How to Harvest
Use a sharp knife or garden shears to cut the bulb just above the soil line. Handle the bulbs carefully to avoid bruising, as damaged kohlrabi may spoil quickly. Trim the leaves and stems, but save them for cooking—they're delicious when sautéed or added to soups.
Frequent Harvesting
Harvest your kohlrabi regularly to encourage continuous production. Leaving mature bulbs in the ground can slow the growth of younger plants and lead to overcrowding.
Improving Taste and Texture
A mild, sweet flavor and tender texture are hallmarks of high-quality kohlrabi. To improve kohlrabi taste, focus on practices that enhance the plant’s natural sugars and reduce bitterness.
Fertilizing for Flavor
Kohlrabi benefits from a steady supply of nutrients, particularly nitrogen during the early growth stages and potassium as the bulbs develop. Use an organic fertilizer, such as fish emulsion or seaweed extract, to provide a balanced nutrient profile. Avoid over-fertilizing with nitrogen late in the season, as this can lead to excessive leaf growth at the expense of bulb quality.
Cool Weather Advantage
Planting kohlrabi during cooler seasons enhances its sweetness. Cold weather stimulates the production of natural sugars, resulting in a more flavorful vegetable. Fall-harvested kohlrabi often tastes sweeter than spring crops due to the gradual cooling of temperatures.
Interplanting for Flavor Boost
Interplant kohlrabi with companion plants like basil, mint, or cilantro, which can enhance its flavor and deter pests. These herbs not only improve garden biodiversity but may also subtly influence the taste of your kohlrabi.
Post-Harvest Storage
For the best flavor and texture, use kohlrabi soon after harvesting. If storage is necessary, keep the bulbs in the refrigerator for up to three weeks. Wrap them in a damp cloth to maintain moisture and prevent drying out.
Common Pests and Diseases
Healthy kohlrabi is less likely to develop a woody texture or off-flavors. Preventing pest and disease issues is critical to maintaining plant health.
Cabbage Worms and Aphids
Kohlrabi belongs to the brassica family, making it a target for cabbage worms and aphids. Use floating row covers to prevent infestations and apply organic insecticidal soap if pests become a problem. Hand-pick worms as needed.
Clubroot
This soil-borne disease can stunt growth and ruin bulb quality. Prevent clubroot by rotating crops and maintaining proper soil pH. Avoid planting brassicas in the same location for consecutive seasons.
Fungal Diseases
Fungal issues like downy mildew can damage leaves and reduce bulb quality. Water at the base of the plants and ensure adequate spacing to improve air circulation.
Organic and Sustainable Growing Practices
Growing kohlrabi organically not only benefits the environment but also enhances the vegetable’s flavor and texture.
Natural Pest Control
Introduce beneficial insects, such as ladybugs and lacewings, to your garden to keep pest populations in check. Avoid synthetic pesticides, which can harm beneficial insects and the soil microbiome.
Composting
Use homemade compost to enrich your soil and provide a steady supply of nutrients throughout the growing season. Compost improves soil structure and promotes healthy root development.
Crop Rotation
Practice crop rotation to prevent soil depletion and reduce the risk of disease. Rotate kohlrabi with non-brassica crops like legumes, which can replenish nitrogen levels in the soil.
