Fuzzy, branching stems carry toothed, lobed leaves and clusters of small yellow flowers, and the large pale yellow seeds end up in the most refined mustards. White mustard (Sinapis alba) is grown both as a spice and as green manure that enriches soil, absorbs noxious nitrates and repels nematodes; give it sun and cool, rich, light soil.
| Botanical name | Sinapis alba |
|---|---|
| Common name | white mustard |
| Family | Brassicaceae |
| Type | spice, green manure |
| Height | 2 ½ feet (70 cm) to 4 feet (120 cm) |
| Planting distance | 2 grams of seeds (a pinch) per sq. yard (m²) |
| Exposure | sun |
| Soil type | cool, rich and light |
| Planting | spring, summer |
| Harvest | spring to summer |
White mustard is a herbaceous annual plant that produces fuzzy, branching stems, serrated (toothy) and lobed leaves, and clusters of small yellow flowers. Typically, it’s used as green manure to increase soil quality. White mustard both enriches the soil it grows in and absorbs noxious nitrates. It also repels nematodes.
Interestingly, this plant is also a perfectly edible spice. The most refined mustards on the Old Continent use its large pale yellow seeds as a key ingredient. Native to North Africa, Europe and the Middle East, white mustard is very easy to grow and doesn’t require much care. A word of caution: don’t confuse white mustard with China mustard.
You should always sow white mustard directly in the plot. Do so anytime from March to May if you hope to harvest its seeds, or from August to September if your goal is to use it as green manure for your vegetable plot.
The same seed serves several purposes, and it is the intended use that decides when you sow and what you cut. This table sets the four uses side by side.
| Use | When to sow | What you take | How it is used |
|---|---|---|---|
| Seed as a spice | Early spring to late spring | Seed pods, snipped before they turn brown | Crushed with water and vinegar for mustard, or eaten raw or grilled |
| Green manure | Late summer to early autumn | The whole plant, cut at the base before it seeds | Left as mulch, tilled in, or steeped as fermented weed tea |
| Salad leaves and shoots | Spring to summer | Young stems while still soft | Added to mesclun, in sandwiches, or instead of arugula on pizza |
| Windowsill sprouts | Any season indoors | Seedlings snipped at a couple of inches tall | Cress-like sprouts for the kitchen |
Spring sowings feed the kitchen, late-summer sowings feed the soil.
Not a very demanding plant at all, actually clearly on the “tolerant of almost any situation” side of things. It’ll even sprout on its own almost anywhere if you drop a few seeds along the way. White mustard is a hardy plant with an annual vegetative cycle that can make do with any soil type.
To truly thrive, however, rich, light and cool soil is the key. It doesn’t like excess moisture, drought, or shade very much. A good location for this spice is full sun or part shade. As long as it gets regular rain and enough sun, white mustard needs absolutely no human intervention at all to keep reappearing year after year. If ever rains are tardy, though, grab the watering can for a round of watering to keep the soil cool.
White mustard is a plant that is highly resistant to most diseases, apart perhaps from clubroot (a form of root rot).
Pests, however, are another matter. Slugs love eating young tender shoots, and older plants are a compatible cabbage moth host.
This plant hasn’t been breed and selected much for disease resistance, so most of its defenses are still inherited from its natural state. The only precaution is to avoid planting mustard and cabbage too close together, or even after one another if you practice crop rotation. Since they’re all from the same family, pests and fungus might spread from one to the other.
For use as a spice, collect the mustard seed pods when they’re already quite dry, which is usually 2 months after having been sown in Spring.
Use white mustard to fertilize your growing beds. Sow and grow, and before the plants go to seed, cut them at the base with a sickle or hedge trimmers.
If you need to use the plot earlier, go ahead: any amount of growth gives lots of nutrients.
Another alternative is to mow them over with a mower in the “mulching” position. The goal is to shred everything up and let the residual clippings sit on the ground as a layer of mulch.
Perfectionists like to till this green manure deeper in the soil with a rototiller, but this isn’t absolutely necessary.
Young stems are also edible – they’re quite tasty, too! Pick them when they’re still soft. White mustard leaves and shoots are simply delicious when added to mesclun, as a greens in sandwiches, or to replace arugula on pizza.
Seeds are almost exclusively destined to become mustard. Steps to make it involve crushing them and mixing the paste with water and vinegar. Connoisseurs know that the seeds can also be eaten raw or grilled. Just add them to your meals, and marinades for the barbecue…
White mustard seed is the mild one: its heat is warm and lingering, not the nose-clearing blast of brown mustard.
Crush the seeds with cold water and wait a few minutes before adding vinegar, because the acid locks in whatever pungency has developed.
Whole seeds also flavour pickling brines beautifully.
Sown thickly in a shallow tray on a bright windowsill, white mustard gives the cress-like sprouts you snip at a couple of inches tall.
Plant only a few square feet for a bowl full of seeds.
