Turnips are a highly adaptable root vegetable that thrives in the cooler temperatures of the spring and fall, making them well-suited for cultivation across Virginia’s varied climate. Planting timing depends significantly on local frost patterns. Turnips offer a dual harvest, providing both leafy greens and a fleshy taproot, but success depends on precise timing to avoid the summer heat that causes roots to become woody.
Optimal Planting Windows for Virginia
Turnips are a cool-season crop, requiring planting dates timed carefully around the last spring frost and the first fall frost to ensure optimal growth. Virginia’s USDA hardiness zones range from 5b in the coldest mountainous regions to 8b in the warmest Tidewater areas. Spring planting is possible, typically beginning two to three weeks before the average last spring frost date, but the goal is to harvest before the soil temperatures rise into the summer heat.
For the mountainous and western regions, which align with zones 6a and 6b, the last average spring frost can occur between late April and mid-May, meaning spring planting must happen very early. In the warmer Tidewater and coastal areas, corresponding to zones 7b and 8b, the last frost may be as early as the first half of April. Spring-planted turnips must mature quickly, in about 40 to 60 days, before the daily temperatures consistently exceed 75 degrees Fahrenheit, which can cause the roots to bolt or develop a strong, bitter flavor.
The preferred and most reliable planting window for high-quality turnip roots in Virginia is late summer for a fall harvest. Fall planting allows the crop to mature as temperatures cool down, a process that concentrates the sugars in the root, resulting in a sweeter, more tender product. Gardeners should count backward the number of days to maturity for their chosen variety, adding an extra two weeks, and sow seeds around 70 days before the first expected hard frost.
This fall planting window generally falls between late August and early September for the cooler western zones, and can extend into early October for the warmer zones along the coast. The roots will tolerate a light frost, which is beneficial for flavor enhancement, but they must be fully harvested before the ground freezes solid.
Soil Preparation and Sowing Techniques
Turnips develop best in a loose, well-draining, and friable soil structure that allows the taproot to expand without resistance. Heavy clay soils should be heavily amended with aged compost or other organic matter to improve drainage and prevent the roots from becoming malformed or stunted. The soil pH should be slightly acidic to neutral, ideally falling between 6.0 and 7.5.
Before sowing, incorporate organic matter into the top six inches of soil and avoid using high-nitrogen fertilizers. Excessive nitrogen promotes vigorous leaf growth at the expense of the developing root, resulting in small or underdeveloped turnip globes. If fertilization is necessary, a balanced or low-nitrogen formula, such as a 5-10-10 granular fertilizer, is appropriate and should be applied before planting or when the seedlings develop their first true leaves.
Turnips are sown directly into the garden bed, as they do not transplant well due to their delicate taproot structure. Sow the small seeds shallowly, covering them with only one-quarter to one-half inch of fine soil. Seeds should be spaced about one inch apart within the row, with rows spaced 12 to 18 inches apart to allow for proper air circulation and cultivation.
Consistent soil moisture is necessary for germination and subsequent root development, requiring about one inch of water per week in the absence of rain. Once the seedlings emerge and reach a height of approximately four inches, they must be thinned to a final spacing of four to six inches between plants. Crowding is a common cause of small or misshapen roots, making the thinning process a required step for a quality harvest.
Harvesting Roots and Greens
Turnips provide a double harvest, yielding both the subterranean root and the above-ground greens, but the harvest strategy depends on the gardener’s primary goal. The first stage of harvesting involves the young greens, which can be picked when the leaves are about four to five inches tall, often coinciding with the thinning process.
If the goal is to produce large, mature roots, greens harvesting must be limited to only the outermost leaves of the plant. Removing too much foliage inhibits the photosynthesis required to produce energy for the root’s growth, significantly slowing its development. The greens are generally at their most tender and flavorful when the temperatures are cool, and they may be harvested repeatedly until a hard frost forces the plant into dormancy.
Turnip roots are ready for harvest when they reach a diameter of two to three inches. Harvesting the roots when they are still relatively small ensures the best texture and mildest flavor, as larger roots tend to become fibrous, woody, and overly pungent. The root is ready when a small portion of the shoulder pushes up through the soil surface, displaying the characteristic color, such as the purple on a ‘Purple Top White Globe’ variety.
Fall-planted turnips should be harvested after the first few light frosts, which enhances the sweetness of the root tissue due to the conversion of starches to sugars. However, all roots must be pulled from the ground before a severe, prolonged freeze, as hard freezing and thawing can cause the roots to crack and rot in the soil. Roots intended for long-term storage should be harvested, the greens removed, and stored in a cool, dark environment just above freezing.