Determining the proper seeding rate for orchard grass (Dactylis glomerata) is central to establishing a successful forage operation. This cool-season perennial grass is highly valued across North America for its versatility in hay production and pasture grazing. The seeding rate directly affects the stand’s density, overall yield, and long-term health. The recommended amount varies significantly based on whether the grass is planted alone, the planting method used, and the intended use of the final forage crop.
Standard Seeding Rates for Pure Stands
For a pure stand, where orchard grass is planted without any other forage species, the general recommendation typically falls between 8 and 12 pounds per acre. Some agricultural extension services and seed companies may recommend planting up to 15 or 20 pounds per acre to achieve a particularly thick initial stand. This measurement relies on the concept of Pure Live Seed (PLS), which is a metric representing the true amount of viable seed in a given seed lot.
Pure Live Seed (PLS) accounts for both the seed’s purity and its germination rate, ensuring the pounds planted are effective pounds of viable seed. The PLS calculation involves multiplying the percentage of pure seed by the percentage of total germination, including any dormant seeds. Using the PLS rate allows a grower to accurately compare seed lots and precisely meet the required plant population. Buying seed based on PLS rather than bulk weight ensures the money spent is only on seed that is capable of growing.
Adjusting Rates Based on Planting Method and Soil
The base seeding rate must be adjusted according to the chosen planting method, as the efficiency of seed placement varies widely. Planting via a seed drill provides the most precise seed placement and optimal seed-to-soil contact, often allowing a grower to use the lower end of the recommended rate. Drilling the seed to a depth of one-quarter to one-half inch ensures consistent moisture access and germination.
Broadcasting, which involves scattering the seed over the soil surface, is inherently less efficient and requires a higher rate to compensate for losses. When broadcasting, it is common practice to increase the seeding rate by 50% to 100%, effectively doubling the amount of seed used compared to drilling. This increase accounts for seed scatter, uneven coverage, and the lower percentage of seed that achieves the necessary soil contact for successful germination.
Soil condition and seedbed quality also influence the final decision on the seeding rate. An ideal, clean, and firm seedbed with good moisture retention may allow for using a lower rate, as expected seedling survival is high. Conversely, planting into poor, rocky, or heavily tilled seedbeds necessitates increasing the rate to counteract the expected higher rate of seedling mortality. In areas with low moisture or dryland conditions, a slightly increased seeding density may be beneficial to ensure a robust stand establishes despite the environmental stress.
Specific Density Targets for Hay and Pasture
The primary purpose of the stand—whether for hay or grazing pasture—guides the final seeding rate decision, as each use requires a different plant architecture. For hay production, the goal is a very dense stand with fine stems to maximize biomass yield and forage quality. Growers aiming for this finer, denser profile often push the seeding rate toward the higher end of the range (15 to 20 pounds per acre). This high density encourages competition, resulting in thinner stems and a higher percentage of leafy material at harvest.
Pasture use, however, can often accommodate a slightly lower initial seeding density, which allows individual plants to develop a broader, more robust crown structure. These wider, more vigorously rooted plants are better equipped to withstand the repeated defoliation and physical trampling associated with grazing livestock. A stand intended for grazing management needs plants that can recover quickly, making a durable plant base more desirable than maximum stem density. The general recommendation of 8 to 12 pounds per acre is often adequate for establishing a resilient grazing stand.
Seeding Orchard Grass in Forage Mixtures
Orchard grass is frequently planted as a component in a mixture, most commonly with legumes such as alfalfa, red clover, or white clover. When planted in a mix, the seeding rate for the orchard grass component is drastically reduced from the pure stand rate. The recommended amount for the grass in a mixture typically falls between 2 and 8 pounds per acre, depending on the desired proportion of grass in the final stand.
This reduced rate is necessary because legumes change the soil nutrient dynamics and fix atmospheric nitrogen, which helps feed the orchard grass. Too much grass seed can lead to excessive competition that crowds out the legume seedlings. The goal of a typical grass-legume mixture is to achieve a mature stand that contains 30% to 40% grass for optimal nutritional balance and persistence. Using a lower seeding rate ensures a proper balance is established, allowing both the grass and the legume to thrive together.