Mustard plants belong to the Brassica species, making them a relative of cabbage and broccoli. This fast-growing crop is cultivated for two distinct purposes: its pungent, sharp-flavored leaves (mustard greens) and its small, oil-rich seeds. Successful cultivation requires understanding its specific needs, from choosing the proper planting window to executing the right harvesting technique. This guide provides a step-by-step approach to growing mustard effectively for both greens and seeds.
Selecting the Right Time and Place
Mustard is a cool-season crop that thrives when temperatures are moderate, making spring or fall the ideal planting windows. Planting should occur four to six weeks before the last expected frost date in spring to ensure a harvest before summer heat arrives. For a fall crop, seeds can be sown in late summer, roughly six to eight weeks before the first expected frost, allowing time for maturity. Hot weather causes the plant to “bolt,” or prematurely flower, resulting in bitter-tasting leaves and a rapid decline in quality.
The chosen location should provide full sun for optimal growth, especially during the cooler shoulder seasons. However, in regions with intense summer heat, planting in a spot that receives partial afternoon shade helps prevent bolting and keeps the leaves tender. Adequate sunlight ensures the plant develops the necessary energy for robust leaf production or seed development.
Preparing the Soil and Sowing the Seeds
Mustard performs best in well-draining soil that is fertile and rich in organic matter, which supports the rapid growth of the leaves. Before planting, the soil should be loosened to a depth of at least six to eight inches, breaking up any compacted areas. Incorporating aged compost or well-rotted manure will significantly improve soil structure and nutrient content.
The optimal soil pH level for mustard is slightly acidic to neutral, typically ranging between 6.0 and 7.0. Once the bed is prepared, the seeds should be directly sown into the garden, as mustard does not transplant well due to its delicate root structure. Plant the small seeds shallowly, about one-quarter to one-half inch deep, and gently cover them with sifted soil.
Spacing depends on the intended harvest: for greens, seeds can be scattered or sown closely in rows, aiming for plants about two inches apart initially. If the goal is seed production, allow more space, thinning later to about six inches between plants to encourage robust branching and flower stalk formation. After sowing, the bed requires a thorough, gentle initial watering to settle the soil around the seeds and initiate germination.
Essential Post-Planting Care
Consistent moisture is required for growing mustard, especially during germination and early leaf development stages. The soil should be kept uniformly moist but never waterlogged, as water stress can accelerate the plant’s tendency to bolt. Watering deeply and less frequently is better than shallow, daily sprinkles, which promote weak root systems.
Once the seedlings have developed two sets of true leaves, they must be thinned to ensure proper air circulation and reduce competition for nutrients. Thinning involves carefully removing weaker seedlings to leave the remaining plants spaced appropriately, promoting good airflow. For continuous leaf harvest, aim for spacing of four to six inches between plants in a row to allow for robust leaf development.
Monitoring for common pests, such as flea beetles, is an important aspect of post-planting care. These small insects chew tiny holes in the leaves, which can stunt growth and reduce the quality of the greens. Simple organic controls, like row covers placed over the seedlings or applications of neem oil, can effectively manage these populations.
Harvesting Mustard Greens and Seeds
Mustard greens are ready for harvest relatively quickly, often within three to four weeks after planting. To maximize the yield, use the “cut-and-come-again” method, which involves snipping the outer, larger leaves first, leaving the central growing point intact. Harvesting the leaves before they grow too large ensures the best flavor and texture, as older leaves become noticeably tougher and more pungent.
For seed production, the plant must be allowed to transition from vegetative growth to reproductive growth, involving bolting and flowering. After the yellow flowers fade, they develop into small, green seed pods called siliques. The stalks should be cut when the pods have dried out and turned a tan or brown color, but before they shatter and drop their seeds.
The harvested stalks should be moved to a dry, protected area to finish drying completely, usually for about two weeks. Seeds are then removed by threshing, which involves gently crushing the dried pods to release the small, round seeds. The clean seeds should be stored in an airtight container in a cool, dark place to maintain viability and prevent spoilage.