Mustard Growing Guide: from seed to kitchen

How to Grow Mustard

The essential guide to growing mustard from seed; with notes on germination, cultivation, harvest and even kitchen uses.

This guide is predominately about mustard greens/leaf to be used fresh in the kitchen.

Mustard Types – Flavour & Kitchen Uses:

Leaf / salad mustards – tender, peppery to wasabi-hot; pick baby leaves for mixed salads, larger leaves for stir-fries, soups and sauté greens.
Seed mustards (white/yellow, brown, oriental) – grown on for pods that ripen to spicy seeds; use whole in pickles, toast for curries or grind for homemade condiments.
Green-manure / bio-fumigant mustards – fast biomass and high glucosinolate roots; dig in at early bloom to boost organic matter and suppress nematodes and soil-borne disease.
Sprouting/microgreen mustards – 5-day shoots pack a sharp punch; garnish sandwiches, sushi and noodle dishes.

Seeds per Gram: ≈ 400 - 600 seeds

Optimal Germination Temperature: 12 – 20 °C (sprouts in 7 – 14 days)

Feed Requirements:

Moderate-high.
Blend plenty of compost or well-rotted manure into the bed and add a nitrogen-rich organic fertiliser (about 60 g m⁻²) before sowing for rapid, mild growth.

Growing Notes:

Climate & Timing

Temperate / cool zones: sow late summer-autumn for winter harvest; a second sowing late winter to early spring provides the first leafy greens before lettuce.
Sub-tropics: autumn-winter sowing only; heat triggers bolting and strong bitterness.
Mustards tolerate light frosts and become sweeter; prolonged heat (>28 °C) causes bolting.

Sowing & Spacing

Direct-sow 3-5 mm deep, 30 – 40 cm between plants, rows 40 – 60 cm apart.
Thin seedlings at two true-leaf stage to give strong plants space: 30 cm in spring, 35–40 cm in autumn.
For continuous supply, broadcast a row every 3 weeks or interplant between slower crops.

Water & Soil

Shallow-rooted; keep the top 5 cm of soil moist with regular deep watering—dry stress makes leaves tough and hot.
Mulch to conserve moisture and suppress weeds.

Care

Feed with liquid seaweed or fish emulsion fortnightly if growth slows.
Net seedlings against cabbage white butterflies.
For seed production reduce watering once plants flower; avoid leaf harvest.

Common Problems:

Slugs & snails: most damage on young plants in early spring—use pellets or traps.
Aphids: spray with strong water jet or insecticidal soap; encourage ladybirds.
Powdery mildew: improve airflow, water soil not foliage, remove infected leaves.

Harvesting:

Leaves:
- Ready 30 – 60 days from sowing.
- Pick outer leaves as needed, or cut whole plants 5 cm above soil for a single harvest; new shoots resprout once in cool weather.
- Eat promptly for best flavour; store washed leaves in a perforated bag in the fridge for up to 5 days.
Flower buds:
- Nip off unopened yellow buds (like mini broccolini) just before bolting—they’re a delicacy steamed or tossed in noodles.
Seeds:
- When pods turn pale brown and rattle, pull whole stems, dry in a paper bag a week, then thresh and winnow.
- Keep seeds cool and dry for cooking or next season’s sowing (viable 3–4 years).
Green manure:
- Slash and dig in at first bloom (about 6 weeks) while stems are still soft; water well to speed decomposition before the next crop.

Sow fresh seed into rich, moist soil, keep the water up, and mustard will reward you with quick, nutrient-packed greens, zesty seeds, or a soil-healing cover—whichever flavour of mustard suits your patch.