Soybeans are a premium food plot option, providing deer with high-protein forage during the summer and high-energy grain in the late season. The foliage can contain up to 30% crude protein, which supports antler growth and fawn development throughout the warm months. Successfully cultivating soybeans requires precise timing and management, as the plant is highly palatable and vulnerable to heavy browsing pressure early in its life cycle. Planting too early risks frost damage, while planting too late prevents the beans from fully maturing before the first killing frost.
Regional Planting Timelines for Maximum Forage
The appropriate time to plant soybeans is dictated primarily by soil temperature and the risk of late-season frost. A minimum soil temperature of 60°F is recommended for optimal germination and strong initial growth. Planting can occur when soil temperatures are reliably above 50°F to avoid imbibitional chilling injury. Waiting until about one month after the average last frost date helps ensure conditions are favorable for seedling survival.
Northern Regions
In northern latitudes, the planting window is narrow, running from early May through late June. The primary goal in this region is often to maximize standing grain for the late-season hunting period due to the shorter growing season. Planting in early to mid-May, once the soil has warmed, allows the plants to maximize vegetative growth and ensures a high yield of pods before the first frost.
Transitional and Mid-Atlantic Regions
The Transitional Zone, which includes the Mid-Atlantic states and parts of the Midwest, offers a longer window, typically from late April to mid-June. Land managers can focus on maximizing summer forage, as the longer season provides enough time for pod development. Planting closer to the end of April or early May allows for heavy summer browsing, with the expectation that the plants will recover and produce late-season pods.
Southern Regions
In the Southern Zone, the planting window is the widest, beginning as early as late March or April and extending through June. Early planting in April allows the plants to establish before the intense summer heat and drought conditions stress later plantings. Later planting, often into June, can still be successful and may provide a flush of fresh, green forage closer to the early archery season. The planting date must allow the selected variety enough time to reach full maturity before the first expected hard frost.
Selecting the Right Soybean Variety
The choice of soybean variety significantly influences the success of a food plot by determining its growth habit and maturity date. Soybeans are categorized into forage varieties and grain varieties, each serving a different purpose for deer management. Forage soybeans are bred to be taller, bushier, and more viney, producing a greater biomass of leaves and stems that better withstand browsing pressure throughout the summer.
Grain soybeans are the varieties typically used in large-scale agriculture, prioritizing the production of high-yield bean pods. These varieties are shorter and more erect, focusing energy on producing carbohydrate-rich grain for late-season energy. The primary drawback of grain varieties in small food plots is their lower tolerance to heavy browsing, as removing their main growing points can quickly kill the plant.
Maturity Group Ratings
Maturity Group (MG) ratings provide a standardized method for selecting a variety appropriate for a specific geographical location. The ratings range from MG 00 in the far north to MG VIII in the deep south, indicating the time required for the plant to reach physiological maturity.
For instance, a land manager in a Northern region might select a shorter-season variety like an MG 3 to ensure pod production before an early frost. In the Southern Zone, a manager might choose a later-maturing MG 5 or 6. This ensures the plants remain green and actively growing, providing forage deep into the fall.
Protecting Young Soybean Plots
Intense browsing pressure immediately following germination is the most common reason for soybean food plot failure, especially in areas with high deer density. Because soybeans are palatable, deer often target the tender seedlings, eating the growing points and killing the young plants. To ensure plot establishment, the planted acreage should be large enough to absorb the initial browse pressure. A plot of at least two acres is recommended in areas with moderate deer populations.
Temporary electric fencing is the most effective physical method for protecting small or vulnerable plots during the first 45 to 60 days of growth. A single-strand electric fence, often called a “New Zealand” style fence, or a simple polywire system, can deter deer long enough for the soybeans to grow past the vulnerable seedling stage. The fence is removed once the plants have developed enough leaf mass and height, typically reaching 18 to 24 inches, to withstand moderate browsing.
Chemical repellents can also be used as a supplementary measure during the initial establishment phase. Products containing odor or taste deterrents, such as Milorganite or liquid sprays, can be applied to the perimeter or directly to the young plants. These repellents help reduce pressure on vulnerable seedlings until the plants are large enough to sustain themselves. Managers may also consider planting a small sacrificial plot of a less attractive forage nearby to temporarily divert attention away from the primary soybean plot.