Turnips and radishes, members of the brassica family, are highly effective components of a late-season food plot strategy for deer. These cool-season annuals are planted in late summer and early fall, providing a dense, nutrient-rich food source when most other natural forage has diminished. The plants’ two-part structure—digestible green tops and energy-dense taproots—offers sustained nutrition and attraction well into the late hunting season and early winter.
Timing for Optimal Forage Availability
The single most important factor for a successful brassica plot is planting at the correct time to allow for full maturity before the season’s first hard freeze. Brassicas require approximately 60 to 90 days of growth to develop substantial root bulbs and leafy biomass. To determine the planting date, count backward 75 days from the average date of the first anticipated hard frost in the area.
Planting too early, typically in the high heat of summer, can cause the plants to mature too quickly, resulting in woody, less palatable greens and a higher risk of insect damage. Conversely, planting too late will not allow turnips and radishes enough time to form the large, energy-rich roots deer rely on during the coldest months. For northern regions, the ideal planting window usually falls between late July and mid-August, while in the mid-South, planting can be delayed until early to mid-September.
Many managers believe a hard frost is necessary for brassicas to “sweeten,” historically thought to be a conversion of starches into sugar. Scientific research suggests that increased consumption is due more to the decline of other available food sources than a significant change in sugar content. Regardless of the exact mechanism, the plot becomes a high-preference food source, providing energy-rich carbohydrates in the roots and high protein in the leaves during a time of nutritional stress.
Soil Preparation and Site Selection
Brassicas thrive in sites that receive at least six hours of direct sunlight daily and possess well-drained, fertile soil. Heavy clay or poorly drained areas should be avoided, as standing water will quickly rot the forming taproots and inhibit proper growth. A good initial seedbed is necessary for establishment.
Soil chemistry is a primary consideration, and a soil test is the only way to accurately determine required amendments. Turnips and radishes prefer a slightly acidic to neutral pH range, ideally between 6.0 and 7.0, with 6.5 being optimal for nutrient availability. If the pH is below this range, the soil should be amended with agricultural lime well in advance of planting, as lime takes time to raise the soil’s acidity level.
Fertilization
Fertilization must be balanced for both leaf and root development, focusing on the three main macronutrients: nitrogen (N), phosphorus (P), and potassium (K). A common initial application at planting is 300 pounds per acre of a balanced fertilizer (e.g., 19-19-19 or 13-13-13), which provides the necessary P and K for root growth. A second, heavy application of nitrogen, such as 75 to 100 pounds per acre of Urea (46-0-0), should be broadcast three to five weeks after germination when the plants are four to eight inches tall. This nitrogen boost is essential for maximizing the lush, high-protein leaf growth that attracts deer early in the season.
Specific Planting Techniques
The final step involves creating a fine, firm seedbed by tilling or disking the plot area until the soil particles are small and uniform. Brassica seeds are extremely small and should be planted very shallowly, no deeper than 1/8 to 1/4 inch, as deeper planting prevents germination. For this reason, disking after broadcasting the seed is not recommended, as it places the seed too deep.
Recommended broadcast seeding rates are approximately 10 to 12 pounds per acre for turnips and 8 to 12 pounds per acre for forage radishes when planted alone. Because the seeds are minute, it is easy to over-seed, which results in overcrowded, stunted plants with small bulbs. To ensure an even distribution, the seed should be mixed with an inert carrier like play sand, pelletized lime, or a portion of the initial fertilizer.
After broadcasting the seed onto the firm seedbed, the area must be rolled or cultipacked to establish firm seed-to-soil contact, which is essential for germination. If a cultipacker is unavailable, dragging a chain harrow or driving over the plot with an ATV can suffice. The best time to plant is immediately before a predicted rain, which naturally settles the seed into the soil and provides the necessary moisture for rapid establishment.