Ever since the average salad shifted from two types of greens to 20, farmers have been growing varieties with increasingly unusual color and flavor. Mustard greens could not be further from the Iceberg lettuce end of the spectrum—not only do they boast stunning shades of green and purple, but their strong flavor is enough to enliven any salad in need of a bite.
At the farm we grow eight varieties of mustards for Manresa Restaurant: Mizuna, Purple Mizuna, Golden Frill, Ruby Streaks, Ho Mi Z, Red Rain, Pepper Cress and Arugula. Each week we sow all eight in our greenhouse where they are tended until harvest roughly four weeks later. The weekly sowing process is the most time-intensive step of mustard growing: we generally sow at least two flats of each variety, and have sown up to 22 flats when the need is high. But sowing a single flat weekly for salad greens is simple and rewarding—all you need are square trays, 4-inch pots, good potting soil and a selection of mustard seeds.
To begin, fill your 4-inch pots with your favorite potting soil (we use Gardner & Bloome's Potting Soil) to just below surface level, taking care not to press down on the soil (this can be done by scooping handfuls of soil loosely into the pot and then shaking gently to level). Next water your soil-filled pots until fully saturated—the soil will compress with the water and you will not have to worry whether your pot is moist after sowing. Take a liberal pinch of seeds and sprinkle evenly over each pot, and here you can experiment a little with density depending on how large you want your mustard greens to grow. Finally cover your seeds with a light layer of soil (just until the seeds are no longer visible) and water with very low pressure three times. Cover with plastic until you see germination (usually 2-5 days). Once the first sprout germinates, remove the plastic and let them bask in the sun (or a very sunny window). Water when dry, and four to six weeks later you will have a full flat of gorgeous greens to harvest!
You need not pull the plants out by the root. It'll make for a more sustainable harvest if you simply cut the greens a bit above the soil level with sharp scissors. They will regrow if they have enough sun and ample water. Expect one or two regrowths until the greens lose their oomph in their pots. But if you've timed it right, you should have another batch coming along right behind them! Don't throw out that soil, though, compost it!
For more information on growing these fabulous greens, and to sow a flat of your own to take home, consider attending Love Apple Farm's Early Spring Vegetable Gardening class coming up in February.
