Leaf Mustards Brassica juncea

Brassica juncea or Brown Mustard is an annual herb in the cruciferous family.  The genus name Brassica is Latin for cabbage.  It has been introduced to all of North America from Eurasia.  It is listed as invasive in some mid-western states.  However, the leaves and flowers of certain cultivars are cultivated for use in the edible garden, having a hot mustard flavor.  Young leaves can be eaten in mixed salads and older leaves are usually cooked as greens.  Some areas of the world also grow it for its spicy seeds.

Mustard grows best in full sun to part shade and well-drained, rich, consistently moist soil.  Watering early in the day will allow the plant to dry before nightfall and reducing the chance of fungal diseases.  As a cool-season plant, it does best in the fall and spring, bolting and developing a strong flavor in the summer.  Some shade is appreciated as the weather turns hot, especially for growing baby greens.  Moisture and temperature stress lead to a spicier, unpleasantly strong flavor as well.  Curly-leaved cultivars tolerate frost better than straight-leaved cultivars.

Sow seeds in the spring 3 weeks before last frost or in late summer as the weather begins to cool.  Thin plants to 6 in apart.  One inch of water per week is vital for proper root development.   They can also be planted in containers at a minimum size of 3 gallons and 4-6 in deep.  New seeds can be planted every 2-3 weeks for a continuous harvest.  They grow to maturity at about 30-50 days after planting and can be harvested at a small "baby" size or larger, mature size.  Baby leaves are best eaten raw while larger leaves improve with cooking.

It also has promise for use in phytoremediation as it tolerates and takes up heavy metals in contaminated soils easily.

Insects, Diseases, and Other Plant Problems:   Considered a noxious weed in some Midwestern states.  Insects affecting this plant include flea beetle, caterpillars, aphids, slugs, and snails.