Wheatgrass is the young shoot of the common wheat plant, Triticum aestivum, harvested early for use in juicing and health supplements. This vibrant green plant is valued for its concentration of compounds, including chlorophyll, vitamins, and amino acids. Successful home cultivation relies on careful timing and understanding its rapid growth cycle to harvest the blades at their maximum nutritional density.
The Ideal Height for Peak Nutritional Value
The most desirable moment to harvest wheatgrass is when the blades reach a height between 6 to 8 inches (15 to 20 centimeters). This measurement aligns with a specific biological phase known as the pre-jointing stage. Harvesting at this point, which occurs 7 to 10 days after planting, ensures the plant has maximized the content of chlorophyll, enzymes, and vitamins.
This optimal window exists because the plant is still in its vegetative growth phase, focusing all its energy on producing nutrient-rich leaf material. Once the wheatgrass grows beyond this 8-inch range, it begins a process called “jointing” where the internodal tissue elongates to form a true grain stalk. At this stage, the plant shifts its metabolic focus, diverting energy from leaf production toward structural development and future seed creation.
This biological change results in a rapid decline in the concentration of beneficial compounds like chlorophyll, protein, and vitamins. Furthermore, the grass develops tougher, more fibrous cell walls composed of indigestible cellulose. This cellulose is responsible for the woody texture and bitter taste of over-mature wheatgrass. Harvesting just before the jointing stage, when the first leaf has split to reveal a second emerging blade, captures the peak nutritional profile before this structural toughening begins.
Environmental Factors Affecting Wheatgrass Growth
The rate at which wheatgrass reaches its optimal height is highly dependent on controlling the growing environment. Light exposure is a major influence, as the young shoots require bright, indirect light to develop their deep green color and high chlorophyll content. Insufficient light results in etiolation, where the grass grows tall but spindly and pale as it stretches to find a light source. Conversely, too much direct, intense sunlight can cause the blades to dry out or overheat, stressing the young plants.
Temperature control also plays a significant role in determining the speed and health of the growth. Wheatgrass thrives within a moderate temperature range, ideally between 60 and 75°F (15 to 24°C). Temperatures falling below this range slow the plant’s metabolic activity, significantly delaying the time to harvest. Sustained temperatures above this window can be detrimental, potentially causing the grass to weaken or even die.
The growing medium, whether soil or a hydroponic mat, requires consistent moisture without becoming waterlogged. Overwatering is a common issue that encourages mold or fungus development near the roots and seed line. Proper air circulation is necessary to prevent these issues, especially in warm, humid conditions. Using a small fan to gently move air across the surface helps keep the seeds dry while maintaining moisture deeper in the substrate.
Practical Timing: Harvesting and Regrowth Cycles
Once the grass reaches 6 to 8 inches and the second blade has emerged, harvesting is straightforward. Use a sharp, clean pair of scissors or a knife to cut the grass just above the root system. The recommended cutting point is approximately 1/4 to 1/2 inch above the surface of the soil or growing medium.
Cutting slightly above the root joint protects the growing crown, allowing the plant to produce a second crop. If the cut is made too close to the roots, the plant may be unable to recover and regenerate growth. The entire tray should be harvested at once to maintain batch consistency.
While a second harvest is possible, and the grass will regrow within a week, this subsequent yield is shorter and diminished in nutritional quality. The plant expended much of the stored energy from the initial seed to produce the first cut, making the second growth less potent. For this reason, most growers discard the root mat after the primary harvest and plant fresh seeds to ensure maximum nutrient density and flavor.