What Soil Does Mustard Need?

Site Selection

• Mustard grows best in well-drained soil in an area that receives morning sun and afternoon shade. Soil with a pH of between 6.0 and 7.5 results in the best growth. Most soil in established garden beds falls within this pH range, but you can use a home soil testing kit to verify the pH prior to planting. The site must drain well so it doesn't become muddy or retain standing water after irrigation, but it also can't drain and dry out too quickly.

Soil Quality

• The addition of organic matter to the bed improves the quality of the soil. The best soil for mustard greens has a loose, crumbly texture that retains moisture without becoming waterlogged. Working a 1-inch layer of compost into the top 6 inches of the bed supplies organic matter and improves the soil quality. If your bed has poor-draining clay or is overly sandy and drains quickly, a thicker 4-inch layer of compost incorporated into the soil can improve it sufficiently for growing mustard.

Fertilization

• Adding fertilizer before you plant provides the mustard with the initial nutrients it needs. An all-purpose fertilizer, such as a 16-16-8 blend, provides sufficient nutrition. Apply 2 cups of the fertilizer over every 50 square feet of bed at the same time you add the compost. Till both the fertilizer and the compost into the soil. A second fertilizer application of 1/2-cup of 21-0-0 blend to every 10-foot row, applied four weeks after planting, supplies the rest of the nutrients necessary for mustard to complete its growth cycle. Apply the fertilizer 6 inches from the base of the plants and water immediately after application.

Moisture Concerns

• Even the best soil can dry out if you don't water regularly. Mustard needs about 1 inch of water weekly, which is enough to moisten the top 6 inches of soil. Watering deeply once weekly allows the moisture to penetrate this deep into the soil instead of just wetting the surface. A 2-inch layer of mulch prevents the moisture from evaporating, so the soil remains moist longer. Mulch also reduces weeds, which could otherwise invade the bed and rob moisture and nutrients from the mustard.