How to Grow Kohlrabi the Right Way: Step by Step

Introduction to Growing Kohlrabi

Kohlrabi, a member of the Brassica family, is an intriguing vegetable known for its unique, bulbous stem that resembles a turnip. This versatile vegetable traces its roots back to Europe, where it has been a staple in many traditional cuisines. Its name is derived from the German words “kohl,” meaning cabbage, and “rabi,” meaning turnip, which alludes to its hybrid appearance and flavor profile.

One of the most compelling reasons to include kohlrabi in your garden is its impressive nutritional profile. Rich in vitamin C, potassium, and dietary fiber, this cruciferous vegetable supports immune function, heart health, and digestive wellness. It’s also low in calories, making it an ideal addition to a balanced diet. Kohlrabi offers a mildly sweet and peppery taste, with a crisp texture that can be enjoyed both raw and cooked, adding versatility to your culinary repertoire.

Growing kohlrabi is rewarding and manageable, even for novice gardeners. This resilient plant thrives in cool-weather conditions, making it perfect for spring and fall planting. Its relatively short growing season means you can enjoy fresh kohlrabi in just a few weeks. Moreover, this vegetable is known for its pest-resistant qualities, contributing to its ease of cultivation.

In the subsequent sections of this blog, we will provide a thorough, step-by-step guide on how to grow kohlrabi successfully. Whether you have a spacious garden plot or are working with limited space in a raised bed or container, you’ll find that kohlrabi can adapt well to various growing conditions. With its myriad health benefits and relatively simple growing requirements, kohlrabi is an excellent choice for gardeners looking to diversify their vegetable crops.

Preparing Your Garden and Soil

Growing kohlrabi successfully hinges largely on the quality of the soil in your garden. Prime soil conditions are essential to ensure robust growth and maximum yield. Ideally, kohlrabi thrives in well-drained, fertile soil with a pH level ranging between 6.0 and 7.5. A neutral to slightly acidic pH level provides the optimum environment for nutrient absorption, which is critical for the healthy development of kohlrabi bulbs and foliage.

The soil type best suited for kohlrabi is loamy soil. This type of soil is a balanced mix of sand, silt, and clay, offering both good drainage and adequate moisture retention. Proper drainage is crucial to prevent waterlogging, which can lead to root rot and other fungal diseases. To enhance the soil structure and fertility, it is recommended to enrich the garden bed with organic matter such as compost or well-rotted manure. Adding a 2 to 3-inch layer of compost and incorporating it into the top 6 to 8 inches of soil can significantly improve soil texture and nutrient content.

When preparing your garden bed for kohlrabi, clear the area of weeds, rocks, and debris. Weeding is essential as weeds compete for nutrients and water, which can hinder the growth of kohlrabi. Use a garden fork or tiller to turn the soil, breaking up clumps to create a fine, crumbly texture. This will ensure that the kohlrabi roots can penetrate easily and access vital nutrients.

Another tip for preparing your garden for kohlrabi planting is to ensure consistent soil moisture levels. Mulching the garden bed with organic mulch, such as straw or shredded leaves, can help retain moisture, reduce weed growth, and regulate soil temperature. This additional step aids in creating an optimal growing environment for kohlrabi, promoting healthier plants and better yields.

Sowing Kohlrabi Seeds

When it comes to growing kohlrabi successfully, proper seed sowing is a crucial first step. Understanding the optimal timing for planting kohlrabi seeds will ensure robust growth and a bountiful harvest. Kohlrabi seeds can be sown either indoors or directly in the garden, depending on your specific needs and local climate.

For those opting to start indoors, it is generally recommended to sow kohlrabi seeds about 4 to 6 weeks before the final frost date in spring. This will allow seedlings to establish themselves under controlled conditions before transplanting them outdoors. When sowing seeds directly in the garden, aim to plant them as soon as the soil can be worked in early spring, or in late summer for a fall harvest. Kohlrabi thrives in cooler temperatures, making these periods ideal for its growth.

Seed spacing is another vital consideration. For optimal growth, plant kohlrabi seeds about ¼ inch deep in well-prepared soil. Sow seeds approximately 2 inches apart in rows, with each row spaced around 12 to 18 inches apart. This spacing allows the plants adequate room to develop and minimizes competition for resources. After germination, which typically occurs within 5 to 10 days with proper moisture, thin seedlings to about 6 to 8 inches apart to ensure each kohlrabi has sufficient space to mature.

Special considerations are essential for successful germination and growth of kohlrabi. Ensuring consistent moisture levels is crucial; seeds need moist but not waterlogged soil to sprout effectively. Additionally, a soil temperature between 45°F and 85°F (7°C and 29°C) is ideal for kohlrabi seed germination. Mulching can help retain soil moisture and regulate temperature. Thus, by carefully timing the sowing and attending to these detailed aspects, you can set the foundation for a thriving kohlrabi crop.

Transplanting Seedlings

Once kohlrabi seedlings have been started indoors, the next crucial step is transplanting them into the garden. Proper timing and handling are essential to ensure the healthy growth of these young plants. Generally, kohlrabi seedlings are ready for transplanting when they have at least two sets of true leaves, often around 4-6 weeks after germination.

Before moving seedlings to their permanent outdoor home, it is crucial to harden them off. Begin this process about a week before transplanting. Start by placing the seedlings outside for a few hours each day, gradually increasing the time they spend outdoors. This gradual exposure helps the plants acclimate to external conditions, reducing transplant shock and increasing their chances of thriving.

When the seedlings are ready, select a cloudy day for transplanting if possible. This reduces the stress of sudden exposure to direct sunlight. In the garden, space the kohlrabi seedlings about 6-8 inches apart, with rows 12-18 inches apart. This spacing allows each plant adequate room to develop its characteristic swollen stem without competition for nutrients and light.

To transplant, dig small holes just big enough to accommodate the seedling’s root ball. Carefully remove each seedling from its starting container, handling it by the leaves to avoid damaging the delicate stem. Place the seedling in the hole, ensuring the soil covers all roots and is firm enough to support the young plant.

After all the seedlings are in place, water them thoroughly to help settle the soil around the roots. Keep an eye on moisture levels in the following days, as young kohlrabi plants need consistent watering to establish themselves well. Ensure the garden bed has good drainage to prevent waterlogging. By following these steps, you can successfully transplant kohlrabi seedlings, giving them a solid start and paving the way for a plentiful harvest.

Caring for Kohlrabi Plants

Proper care is essential for the successful growth of kohlrabi. Firstly, watering plays a pivotal role. Kohlrabi plants thrive best in consistently moist soil, which requires regular watering, ideally 1 to 1.5 inches per week. To maintain optimal moisture levels, it is crucial to water deeply, ensuring the water reaches the plant roots. Utilizing a soaker hose or drip irrigation system can be especially effective in preventing water from evaporating too quickly.

Fertilizing kohlrabi is another key aspect of its care. An all-purpose organic fertilizer should be incorporated into the soil during planting. Subsequently, bi-weekly applications of a liquid fertilizer can greatly enhance plant growth. High nitrogen fertilizers, in particular, are beneficial early on since they promote robust leafy growth. However, as the plant matures, switching to a balanced fertilizer helps in the proper development of the bulb.

Mulching around the base of kohlrabi plants offers innumerable benefits. It not only helps in maintaining soil moisture but also efficiently controls weed growth. Organic mulches, such as straw, grass clippings, or compost, are highly recommended as they also contribute valuable nutrients to the soil as they decompose. A layer of mulch about 2-3 inches thick is ideal for achieving these benefits.

Preventing weeds is critical to ensure that kohlrabi plants are not competing for nutrients and water. Mulching naturally suppresses weed growth, but regular weeding, particularly during the plant’s early stages, ensures healthier and more vigorous plants. Employing organic weed control methods, such as hand pulling or hoeing, helps maintain an organic garden ecosystem.

By adhering to these guidelines for watering, fertilizing, and mulching, and emphasizing the use of organic fertilizers, one can significantly enhance the health and yield of kohlrabi plants. Consistent care and monitoring enable gardeners to produce robust and flavorful kohlrabi, tailored to their growing environment.

Dealing with Pests and Diseases

Growing kohlrabi comes with its fair share of challenges, including various pests and diseases. One of the most common pests that affect kohlrabi is flea beetles. These small, black insects can cause significant damage by creating numerous small holes in the leaves, which can stunt the plant’s growth. To manage flea beetles, gardeners can use floating row covers to protect young plants or introduce beneficial insects like ladybugs that prey on flea beetles. Organic treatments, such as neem oil, can also be effective in controlling these pests.

Another prevalent issue is clubroot, a disease caused by the soil-borne pathogen Plasmodiophora brassicae. Clubroot leads to the swelling and distortion of the roots, impeding the plant’s ability to absorb water and nutrients. This results in stunted growth and wilting. To prevent clubroot, rotate crops and avoid planting kohlrabi in the same soil more frequently than every three years. Adjusting soil pH to around 7.2 by adding lime can also inhibit this pathogen. Infected plants should be removed and destroyed promptly to prevent the disease from spreading.

Aphids are another pest that can affect kohlrabi. These small, soft-bodied insects suck sap from the leaves, causing leaves to yellow and curl. Aphids also excrete honeydew, which can lead to sooty mold. Introducing natural predators such as ladybirds or parasitoid wasps can help control aphid populations. Spray organic insecticidal soap can also be used to manage aphid infestations.

Preventive measures are effectively managing pests and diseases in kohlrabi. Regular monitoring of the plants allows for early detection of any issues. Ensure proper spacing to promote good air circulation and reduce the humidity that favors disease development. Adequate watering practices, avoiding overhead irrigation, and encouraging beneficial insect populations can collectively maintain a healthy kohlrabi crop.

Harvesting Kohlrabi

Determining the optimal time to harvest kohlrabi is crucial for ensuring the best flavor and texture. Typically, kohlrabi is ready for harvest when the bulbs reach a diameter of 2 to 3 inches, roughly the size of a tennis ball. This usually occurs between 45 to 60 days after planting, although it can vary slightly depending on the specific variety and growing conditions. Gardeners should look for bulbs that are firm and healthy, showing no signs of splitting or excessive fibrousness.

Timing is also important when harvesting kohlrabi. Ideally, it should be picked in the spring or fall when temperatures are cooler, as excessive heat can cause the bulbs to become woody and tough. Early morning or late evening are the best times for harvesting, as cooler temperatures help maintain the kohlrabi’s crispness and nutritional value.

To harvest kohlrabi without causing damage to the plant, use a sharp knife or garden shears to cut the bulb just above the soil line. It’s important to handle the vegetable gently to prevent bruising. The leaves can be left attached for easier handling and transport; however, they should be removed before storage as they can draw moisture away from the bulb.

Post-harvest handling and storage are critical for maintaining the quality of kohlrabi. After harvesting, promptly remove any remaining dirt and lightly rinse the bulbs. Excess moisture should be avoided as it can lead to rot. Store kohlrabi in a cool, humid environment such as a refrigerator crisper drawer. When stored properly, kohlrabi can remain fresh for several weeks. For longer-term storage, kohlrabi can also be peeled, sliced, and blanched before freezing.

By adhering to these best practices for harvesting and storing kohlrabi, gardeners can enjoy a plentiful and delicious supply of this nutritious vegetable throughout the growing season and beyond.

Frequently Asked Questions

Growing kohlrabi can be a rewarding endeavor, but it’s not uncommon for gardeners to have a few questions along the way. Below, we address some frequently asked questions to assist you in your kohlrabi cultivation journey.

1. What is the best time to plant kohlrabi?

Kohlrabi thrives in cooler weather. The optimal planting times are early spring or late summer. Spring planting allows kohlrabi to mature before summer heat sets in, while late summer planting develops as temperatures cool in the fall.

2. How much space does kohlrabi need?

Each kohlrabi plant should be spaced around 12 inches apart to ensure enough room for the bulb to develop fully. Proper spacing also helps reduce competition for nutrients.

3. What kind of soil does kohlrabi require?

Kohlrabi prefers well-drained, loamy soil rich in organic matter. A soil pH between 5.5 and 6.8 is ideal. Adding compost before planting can enhance soil quality and provide necessary nutrients.

4. How often should kohlrabi be watered?

Consistent moisture is crucial for kohlrabi. Water the plants regularly to keep the soil evenly moist, but be cautious of waterlogging. Mulching around the base help retain moisture and regulate soil temperature.

5. Is kohlrabi prone to specific pests or diseases?

Like other brassicas, kohlrabi can be susceptible to pests such as cabbage worms and aphids. Implementing crop rotation and using natural predators like ladybugs can mitigate these problems. Watch for fungal issues like clubroot and employ proper soil management practices to prevent them.

6. When is kohlrabi ready to harvest?

Kohlrabi is usually ready to harvest when the bulb reaches 2-4 inches in diameter. Harvesting at this size ensures a tender and flavorful vegetable. Overgrown kohlrabi can become woody and less appetizing.

These answers should help address common queries, facilitating a smoother experience for anyone looking to grow kohlrabi the right way.