Oat grass, known scientifically as Avena sativa, is a fast-growing cereal crop often cultivated for purposes other than grain harvest. People commonly grow this grass for juicing, as a supplement to human diets, or as a fresh treat for pets like cats and dogs. Its rapid growth cycle allows for quick yields, making it a popular choice for indoor gardening. This guide provides a process for successfully cultivating a continuous supply of oat grass at home.
Gathering Supplies and Choosing Location
You must acquire high-quality oat seeds, which should be non-treated, often sold as “hulless oats” or “cat grass seeds” to ensure they are safe for consumption. For planting, you will need shallow, flat containers or trays, ideally with drainage holes to prevent water accumulation.
A standard seed starter mix or light potting soil works well as the growing medium. The decision between indoor or outdoor cultivation depends on your climate and desired yield. Indoor growth requires a location that receives ample sunlight, such as a south-facing window, or a setup with supplemental grow lights.
If you opt for outdoor planting, the timing is typically early spring or fall, as Avena sativa prefers cooler temperatures for germination and growth. The growing location should be stable, allowing you to easily manage the temperature and light exposure.
Sowing the Seeds
Thoroughly moisten the soil mix until it is uniformly damp but not saturated or muddy. Oat grass requires a much higher seeding density than is typical for field crops. For grass meant for juicing or consumption, the goal is a dense carpet of shoots, which necessitates broadcast sowing.
Spread the seeds across the surface of the soil so they are touching or nearly touching, forming a thick, single layer that covers almost the entire surface area. Avoid piling the seeds on top of one another, as this can hinder air circulation and increase the likelihood of mold development. After spreading, gently press the seeds into the soil to ensure good seed-to-soil contact, which aids in germination.
Unlike many seeds that require deep burial, oat grass seeds only need a light covering or can be left exposed on the surface. If you choose to cover them, a very thin layer of soil or vermiculite is sufficient, followed by a light misting of water to settle the seeds. To promote initial germination, some growers cover the tray with a lid or plastic wrap for the first two to four days, keeping the seeds in darkness and maintaining high humidity.
Essential Care for Rapid Growth
Once the seeds germinate, usually within a few days, maintaining the correct environment becomes the focus for achieving rapid, robust growth. Oat grass thrives in moderate temperatures, with an optimal range generally between 59°F and 77°F (15°C to 25°C). After removing any initial cover, the seedlings require significant light exposure, ideally six or more hours of full sun, or placement directly under a supplemental light source to promote photosynthesis and a vibrant green color.
The growing medium must remain consistently moist, but never waterlogged, as excess moisture is a primary cause of fungal issues. Watering from the bottom of the tray can help the soil wick up moisture evenly without wetting the dense blades of grass.
A common issue in dense plantings is the development of mold, often appearing as white, cotton-like fluff on the soil surface or around the seeds. This is usually a result of poor airflow and high humidity. To remedy this, immediately introduce gentle air circulation using a small fan directed across the surface of the grass, which helps dry the air and inhibits fungal proliferation.
Harvesting and Replanting Cycles
Oat grass reaches its harvestable stage, typically ready within 7 to 10 days after planting, when the blades stand between 4 and 6 inches tall. Harvesting at this height captures the maximum nutritional value before the plant begins to transition its energy toward producing grain. Use clean, sharp scissors to cut the blades of grass about half an inch to one inch above the soil line.
This method leaves the root system and the meristematic tissue intact, allowing the plant to regrow and produce a second, and sometimes a third, flush of grass. After the third cut, the root mat is usually exhausted, and the quality and density of the grass significantly decline.
To ensure a continuous supply of fresh oat grass, establish a sequential planting schedule. Starting a new tray of seeds every 7 to 10 days, or immediately after the first harvest of an existing tray, allows one batch to be ready for cutting as another is completing its productive life. This cycle ensures a steady rotation of young, vibrant grass is always available for use.