Turnips are a fast-growing, cool-season crop valued in Louisiana gardens for their nutritious greens and crisp roots. The mild Southern climate allows for two distinct planting seasons, enabling gardeners to enjoy a continuous supply. Understanding the specific timing is crucial, as turnips quickly develop a bitter taste and woody texture when exposed to the intense heat of a Louisiana summer.
Optimal Planting Windows for Louisiana Turnips
Planting time is dictated by the turnip’s preference for cool weather, ideally with air temperatures ranging from 40°F to 75°F. Louisiana’s long growing season supports a primary planting window in the fall and a secondary, shorter window in the spring. The sweetest-tasting turnips are grown during the cooler months of the year.
For gardeners in Northern Louisiana (USDA Hardiness Zones 8a and 8b), the main fall planting season begins around mid-July and extends through mid-November. The goal is to ensure the crop matures before the first hard freeze, which typically occurs later in the year. A light frost can enhance the flavor by concentrating sugars in the root.
In Southern Louisiana (Zones 9a and 9b), the fall planting window is slightly extended, running from mid-July through the end of November. The spring planting season is a quick race to harvest before summer heat arrives. The recommended spring window is February 1st to March 30th in the South and February 1st to March 15th in the North. To guarantee a continuous harvest, practice succession planting by sowing small batches of seeds every two to three weeks within the recommended season.
Soil Preparation and Planting Technique
Turnips thrive in loose, well-draining soil, such as a sandy loam, which allows taproots to expand easily. Before planting, the soil bed should be worked 6 to 8 inches deep and amended with well-rotted compost or manure to increase organic matter. The ideal soil pH is slightly acidic to neutral, falling within the 6.0 to 6.8 range.
Turnips do not transplant well and must be direct-sown into the garden bed. Seeds should be planted shallowly, about one-quarter to one-half inch deep, and covered lightly with soil. While nitrogen is required for healthy leaf growth, excessive application early on encourages a large canopy of greens at the expense of root development. A balanced, low-nitrogen fertilizer, such as 5-10-10 or 8-16-16, is preferable to promote uniform growth.
Essential Post-Planting Care
The most important step after germination is thinning the seedlings once they reach about 4 inches tall. Crowded plants compete for nutrients and space, resulting in small or malformed roots. Seedlings should be thinned to stand 4 to 6 inches apart to allow sufficient room for the roots to bulb out.
Consistent soil moisture is necessary throughout the growing period; turnips require about one inch of water per week. Inconsistent watering can lead to roots that are tough, woody, or prone to cracking. Common Louisiana pests, such as flea beetles and aphids, may target the tender greens. Pests can be managed organically by covering young seedlings with a lightweight floating row cover or by applying neem oil or insecticidal soap to the foliage.
Harvesting Turnip Roots and Greens
Turnips offer a dual harvest, with the greens ready for picking well before the roots. Turnip greens can be harvested using a “cut and come again” method, starting about four weeks after planting. Selectively snip the outer leaves when they are 4 to 6 inches tall, leaving the inner leaves intact to fuel root development.
The roots are ready for harvest 40 to 60 days after sowing. They are best harvested when the bulb is tender and sweet, typically reaching 2 to 3 inches in diameter. Leaving the roots in the ground too long will cause them to become woody, pungent, and bitter. After harvesting, roots and greens should be stored separately, with the greens removed from the roots to prevent moisture loss and prolong storage life.