Turnips, scientifically known as Brassica rapa, are a versatile and nutritious root vegetable that has been cultivated for thousands of years. They belong to the Brassicaceae family, which includes other well-known vegetables like cabbage, broccoli, and kale. Turnips are valued for their edible roots and leafy greens, both of which are rich in vitamins and minerals. Known for their slightly peppery flavor, turnips are a staple in many culinary traditions, particularly in Europe and Asia.
Turnip Overview
Botanical Background and Global Popularity
Turnips are believed to have originated in Europe and Asia, where they have been cultivated since ancient times. The vegetable has a long history of use as a food source, both for humans and livestock. Turnips are widely grown in temperate regions around the world, with significant production in Europe, North America, and Asia. They are particularly popular in the United Kingdom, France, Japan, and Korea, where they are used in a variety of dishes, from soups and stews to pickles and salads. The root is the most commonly consumed part, but the young, tender greens are also edible and highly nutritious.
Edible Parts and Culinary Uses
Turnips are known for their edible roots, which can be white, purple, or yellow, depending on the variety. The roots can be eaten raw, cooked, or pickled, offering a slightly sweet and peppery flavor. Turnips are often roasted, boiled, or mashed, and are commonly used in soups, stews, and casseroles. The young greens, known as turnip greens, are also edible and can be sautéed, steamed, or added to salads. Turnip greens are rich in vitamins A, C, and K, as well as calcium and iron, making them a valuable addition to a balanced diet.
Suitable Planting Season
Optimal Time for Sowing Turnips
Turnips are a cool-season crop that thrives in mild temperatures. The best time to plant turnips is in early spring or late summer, depending on your climate. In temperate regions, turnips can be sown as soon as the soil can be worked in the spring, typically when temperatures are between 10°C and 24°C (50°F to 75°F). This timing allows the plants to establish before the heat of summer, which can cause the roots to become tough and woody. In regions with mild winters, turnips can also be planted in late summer or early autumn for a fall or winter harvest.
Seasonal Considerations for Different Climates
In cooler climates, turnips can be grown throughout the spring and fall, with some varieties even tolerating light frosts. In warmer climates, turnips are best planted in the fall or winter to avoid the hot summer months, which can negatively impact root quality. Succession planting, or sowing seeds every few weeks, can help ensure a continuous supply of fresh turnips throughout the growing season. In very hot climates, it may be necessary to choose heat-resistant varieties or provide shade during the hottest part of the day to maintain root quality.
Ideal Soil Type
Soil Composition and Texture
Turnips grow best in well-draining, fertile soil with a light, crumbly texture. The ideal soil should be rich in organic matter, such as compost or well-rotted manure, which provides the nutrients necessary for healthy root development. Loamy soil is ideal for turnips, as it retains moisture without becoming waterlogged. Heavy clay soils can be problematic, as they tend to hold too much water, leading to poor root development and increased risk of disease. If your soil is heavy or compacted, consider amending it with organic matter to improve its structure and fertility.
Soil pH and Fertility
Turnips prefer a slightly acidic to neutral soil pH, ideally between 6.0 and 7.0. Maintaining the correct pH is important for nutrient uptake, particularly for phosphorus and potassium, which are crucial for root development. Regular soil testing can help you monitor and adjust the pH as needed. Turnips are relatively heavy feeders, so it is beneficial to incorporate a balanced organic fertilizer or compost into the soil before planting. Side-dressing with compost or applying a liquid fertilizer during the growing season can also help maintain soil fertility and support vigorous growth.
Sowing Tips
Preparing the Soil for Sowing
Before sowing turnip seeds, it is essential to prepare the soil thoroughly. Start by removing any weeds, rocks, and other debris from the planting area. Loosen the soil to a depth of about 20 cm (8 inches) and incorporate a generous amount of compost or well-rotted manure to improve fertility and drainage. If you are planting in raised beds, make sure the soil is well-drained and has a fine, crumbly texture that allows the small seeds to germinate easily. For best results, lightly moisten the soil before sowing to create an ideal environment for seed germination.
Sowing Technique and Seed Spacing
Turnip seeds can be sown directly into the garden bed or started indoors for later transplanting. To sow directly, plant the seeds about 1.25 cm (½ inch) deep in rows spaced 30 cm (12 inches) apart. The seeds should be spaced 5 to 7.5 cm (2 to 3 inches) apart within the row to allow for sufficient root development. If you prefer to start seeds indoors, sow them in trays or pots filled with a high-quality seed-starting mix, and transplant the seedlings when they are about 7.5 cm (3 inches) tall and have at least two sets of true leaves.
Protection and Germination
Turnip seeds typically germinate within 5 to 10 days, depending on soil temperature and moisture levels. To protect the seeds and encourage even germination, consider covering the seedbed with a thin layer of mulch or a row cover, especially in cooler climates. This helps maintain consistent soil moisture and temperature, reducing the risk of poor germination or seedling damage. Once the seedlings have emerged, thin them to a spacing of 10 to 15 cm (4 to 6 inches) apart to allow for proper growth and air circulation.
Is Year-Round Harvesting Recommended?
Feasibility of Continuous Harvest
Turnips can be harvested throughout the growing season with careful planning and succession planting. However, year-round harvesting is not typically recommended, as turnips prefer cooler temperatures and can become tough and woody in response to prolonged heat. In regions with mild winters, turnips can be grown almost year-round, with the main harvest periods in spring and fall. For a continuous supply of fresh roots, sow a new batch of seeds every two to three weeks during the growing season. In very hot climates, it may be necessary to pause planting during the peak of summer and resume in late summer or early autumn.
Succession Planting for Extended Harvest
Succession planting is an effective strategy for extending the turnip harvest over several months. By sowing seeds every few weeks, you can ensure a steady supply of tender, young roots without overwhelming yourself with too much produce at once. This method works particularly well in regions with variable climates, as it allows you to adjust planting times based on weather conditions. In cooler climates, consider using a cold frame or row cover to protect the plants from frost and extend the harvest into winter.
Growth Speed Reference
Germination and Early Growth
Turnips are a relatively fast-growing crop, particularly when grown in optimal conditions. Seeds typically germinate within 5 to 10 days, and the seedlings are hardy enough to tolerate light frosts. During the first few weeks after germination, turnip plants focus on developing a strong root system and producing their first set of true leaves. The plants grow rapidly in cool, moist conditions, with baby turnips ready for harvest within 30 to 40 days after planting.
Time to Maturity and Harvest
Depending on the variety and growing conditions, turnips are usually ready to harvest within 30 to 60 days from sowing. The roots can be harvested at various stages, from small, tender baby turnips to full-sized mature roots. For baby turnips, harvesting can begin as early as 30 days after sowing. Mature turnip roots are typically ready for harvest within 50 to 60 days. It is important to harvest the roots regularly to encourage continued growth and prevent them from becoming woody or overly large.
Considerations for Different Varieties
Different turnip varieties may have slightly varying growth rates and harvest times. For example, fast-growing varieties like ‘Hakurei’ or ‘Tokyo Cross’ are often ready for harvest in as little as 30 to 40 days, while slower-growing varieties like ‘Purple Top White Globe’ may take up to 60 days to reach full maturity. When selecting a variety, consider your local growing conditions and the desired harvest time. Heat-resistant varieties may be better suited for summer planting, while cold-hardy varieties can extend the harvest into late fall or early winter.
Temporary Shade for Hot Weather
Heat Tolerance and Risks
Turnips are sensitive to heat and long daylight hours, which can cause the roots to become tough and woody. In regions where summer temperatures regularly exceed 27°C (80°F), turnips may benefit from temporary shading, particularly if they are grown in full sun. Providing some form of shade during the hottest part of the day can help prevent the roots from becoming too large or developing a bitter flavor.
Methods for Providing Shade
If you are growing turnips in a hot climate or during the peak of summer, consider using shade cloth to reduce the intensity of sunlight. A shade cloth with 30-50% light reduction is usually sufficient to protect the plants from excessive heat while still allowing enough light for photosynthesis. Alternatively, planting turnips in an area that receives morning sun and afternoon shade can help mitigate the effects of high temperatures. For container-grown turnips, simply moving the pots to a shaded area during the hottest part of the day can also be effective.
Watering Tips
Importance of Consistent Moisture
Turnips require consistent moisture to produce tender, succulent roots. Inconsistent watering can lead to tough, bitter roots and increase the risk of bolting. It is important to keep the soil evenly moist but not waterlogged, particularly during the early growth stages and as the roots begin to mature. Overwatering should be avoided, as it can lead to root rot and other fungal diseases.
Watering Technique
For best results, water turnips deeply and regularly, focusing on the root zone. Drip irrigation systems or soaker hoses are ideal, as they deliver water directly to the soil without wetting the foliage, reducing the risk of disease. If watering by hand, apply water slowly at the base of the plants to allow it to penetrate deeply into the soil. Mulching around the plants with organic material such as straw, compost, or shredded leaves can help retain soil moisture and reduce the need for frequent watering.
Mulching to Retain Moisture
Applying a mulch layer of 5 to 7.5 cm (2 to 3 inches) around the base of the plants can help retain soil moisture, suppress weeds, and keep the soil cool. Mulch also helps to reduce water evaporation from the soil surface, which is particularly beneficial during hot, dry periods. Organic mulches such as straw, grass clippings, or shredded leaves are ideal, as they also contribute to soil fertility as they break down.
Recommended Watering Timing
Best Times to Water Turnips
The best time to water turnips is early in the morning, allowing the soil to absorb the water before the heat of the day. Morning watering ensures that the plants have access to moisture throughout the day, which is especially important during hot weather. Watering in the morning also helps reduce the risk of fungal diseases, as the foliage has time to dry out before nightfall. In particularly hot or dry conditions, a second watering in the late afternoon may be beneficial, but avoid watering too late to prevent the plants from staying wet overnight.
Adjusting Watering Based on Weather
Watering frequency should be adjusted based on weather conditions. During cooler, wetter periods, less frequent watering is needed, while in hot, dry weather, more frequent watering may be necessary to maintain consistent soil moisture. Monitoring the soil moisture level regularly and adjusting your watering schedule accordingly will help ensure that your turnip plants receive the right amount of water at the right times.
Watering Frequency Reference
General Guidelines
Turnips typically require watering once or twice a week, depending on the weather and soil conditions. In sandy soils, which drain quickly, more frequent watering may be necessary, while in heavier soils, less frequent watering may be required. The key is to keep the soil consistently moist but not waterlogged, particularly during the growing season when the roots are being produced.
Indicators of Proper Watering
To determine whether your turnip plants are receiving enough water, check the soil moisture level at a depth of about 15 cm (6 inches). If the soil feels dry at this depth, it is time to water. Additionally, wilting leaves, particularly in the early morning or evening, can be a sign that the plants need more water. However, if the leaves remain wilted during the heat of the day but recover by evening, it may be a normal response to high temperatures rather than a sign of water stress.
Pest and Disease Control
Common Pests Affecting Turnips
Turnips are relatively hardy but can be affected by a few common pests, including flea beetles, aphids, and root maggots. Flea beetles are tiny, black insects that chew small holes in the leaves, which can stunt growth, especially in young plants. Aphids are small, sap-sucking insects that can weaken plants and spread diseases. Root maggots are larvae that feed on the roots, causing damage and reducing the quality of the crop.
Integrated Pest Management Strategies
To manage these pests, gardeners can use a combination of cultural, mechanical, and biological control methods. Regular monitoring and early intervention are crucial. Insecticidal soaps or neem oil can be effective against aphids and flea beetles, while row covers can protect young plants from root maggots. Encouraging beneficial insects, such as ladybirds and lacewings, can also help keep pest populations in check. Additionally, maintaining healthy, well-watered plants can make them less susceptible to pest infestations.
Common Diseases and Prevention
Turnips are also susceptible to several fungal diseases, including downy mildew, powdery mildew, and root rot. Downy mildew causes yellowing and distortion of the leaves, while powdery mildew appears as a white, powdery coating on the foliage. Root rot is caused by waterlogged conditions and can lead to the decay of the roots, reducing the quality of the crop.
To prevent these diseases, ensure good air circulation by properly spacing plants and avoiding overhead watering. Crop rotation and removing plant debris at the end of the season can also reduce the likelihood of disease recurrence. In cases where fungal diseases are detected early, fungicidal sprays can help manage the outbreak.
Seed Preservation and Storage Methods
Harvesting and Preparing Seeds
Turnip seeds can be saved from mature plants that have bolted and produced seed stalks. To save seeds, allow the plants to flower and produce seeds. Once the seeds have matured and dried on the plant, they can be harvested by cutting the seed stalks and placing them in a paper bag. After the seeds have fully dried, they can be cleaned and stored for future planting.
Optimal Storage Conditions
Store turnip seeds in an airtight container in a cool, dry, and dark place. A temperature of around 5°C to 10°C (41°F to 50°F) is ideal for seed storage. Properly stored turnip seeds can remain viable for up to 4 years. Labeling the container with the date of harvest and the variety name can help you keep track of your seed inventory.
Preserving Edible Parts and Storage Duration
Post-Harvest Handling
After harvesting, turnip roots should be handled gently to avoid bruising, which can lead to rapid deterioration. The roots can be stored in the refrigerator for up to two weeks. To store them, remove the greens and place the roots in a plastic bag with paper towels to absorb excess moisture. The greens can be stored separately in the refrigerator for up to a week.
Short-Term and Long-Term Storage
For longer storage, turnip roots can be stored in a root cellar or another cool, dark place for several months. If storing them in the ground over winter, cover the area with a thick layer of mulch to prevent the soil from freezing. Turnip roots can also be pickled or canned for longer-term preservation. Freezing is not recommended for turnips, as it can negatively affect their texture.
Nutritional Content of Edible Parts
Nutritional Breakdown
Turnips are a highly nutritious root vegetable, rich in vitamins and minerals. The roots are an excellent source of vitamin C, which supports the immune system and helps the body absorb iron. They also contain significant amounts of fiber, potassium, and calcium. Turnip greens are even more nutrient-dense, providing high levels of vitamins A, C, and K, as well as folate, calcium, and iron. Both the roots and the greens are low in calories, making them a healthy addition to any diet.
Health Benefits and Comparisons
In addition to their high nutrient content, turnips offer several health benefits. The high levels of vitamin C in turnip roots support the immune system and protect against oxidative stress. The fiber in turnips aids in digestion and helps maintain healthy blood sugar levels. Turnip greens are particularly rich in antioxidants and anti-inflammatory compounds, which may help reduce the risk of chronic diseases such as heart disease and cancer. Compared to other root vegetables, turnips are particularly low in calories and carbohydrates, making them an excellent choice for those managing their weight or blood sugar levels.
