Turnips are a versatile root vegetable, valued for their distinct flavor and texture. Their size significantly impacts culinary use, from small, tender roots for fresh salads to larger specimens suited for cooking. Understanding how to influence turnip size allows gardeners to cultivate this vegetable for their desired purpose.
Understanding Typical Turnip Sizes
Turnips vary in size, largely determined by their cultivar. Smaller salad varieties like Hakurei typically mature to 1-2 inches in diameter, offering a sweet, crisp texture ideal for raw consumption. In contrast, larger, traditional varieties such as Purple Top White Globe can grow to 3-5 inches, sometimes reaching 6 inches. These larger turnips are preferred for cooking, as their flavor is more pronounced and their flesh denser. Other varieties like ‘Gold Ball’ or ‘Amber Globe’ also reach 3-5 inches, with peak flavor often at around 3 inches.
Key Factors Influencing Turnip Size
Several environmental and genetic factors determine the ultimate size a turnip root will achieve. Turnips thrive in fertile, well-draining soil; compacted or heavy clay soils impede root expansion, resulting in smaller, potentially malformed turnips.
Nutrient availability is crucial; nitrogen promotes leafy growth, while phosphorus and potassium are important for robust root development. Too much nitrogen can lead to abundant greens but stunted roots.
Consistent moisture is another significant determinant of size and quality; erratic watering or drought can cause turnips to become woody, bitter, or even split. Overcrowding is a common issue, as turnips require adequate space for roots to expand without competition, directly affecting individual root size.
The inherent genetics of the turnip variety also sets a maximum potential size. Temperature and sunlight are critical; turnips are cool-season crops, preferring 40°F to 75°F and at least six to eight hours of direct sunlight daily. High temperatures can stress plants, leading to bolting or strong-flavored, woody roots.
Cultivation Practices for Optimal Size
Specific cultivation practices help achieve desired turnip size. Soil preparation is primary; amending heavy clay or sandy soils with organic matter (compost or well-rotted manure) improves drainage, aeration, and fertility, creating the loose environment turnips favor for root development. An optimal soil pH is between 6.0 and 7.5; a soil test can determine if adjustments are needed.
A balanced fertilization strategy encourages root growth. While initial soil amendments often provide sufficient nutrients, a low-nitrogen or balanced fertilizer (e.g., 5-10-10 NPK ratio) can be side-dressed once seedlings develop true leaves. Avoiding high-nitrogen fertilizers is crucial for root crops, as excess nitrogen prioritizes leafy top growth over root expansion.
Consistent, deep watering (about one inch per week) is essential to prevent stress and ensure continuous root development, especially during dry spells. Mulching also helps maintain consistent soil moisture and suppress weeds. Thinning seedlings is critical for achieving larger turnips. After germination, thin seedlings to allow 4 to 6 inches of space between plants, providing individual roots ample room to expand without competition.
Selecting turnip varieties known for their mature size, such as ‘Purple Top White Globe’ for larger roots or ‘Hakurei’ for smaller ones, aligns cultivation efforts with specific size goals. Managing common pests and diseases also supports larger root development by keeping plants healthy.
Harvesting Turnips for Desired Size
The timing of harvest significantly influences the final size, flavor, and texture of turnips. For small, tender, and sweeter turnips, harvest when they are about 1-2 inches in diameter. These early harvests typically occur 30-50 days after sowing, depending on the variety.
For larger turnips suitable for roasting or stews, allow them to grow to 3-5 inches in diameter. Monitor growth, as turnips can become woody, pithy, or bitter if left in the ground too long, especially in hot weather. The top of the turnip root often pushes out of the soil, providing a visual cue for its size and readiness. Harvest by gently pulling the turnip from the ground, potentially loosening the soil first, to avoid damage.