White Mustard

How to sow

Sow surface. Use peat-free coco. Keep the surface just moist.

Germination 2–4 days in the crop record.

Growing

1. Sowing — Day 0. Scatter seeds densely on moist compost. Press gently. No cover needed — mustard micros are vigorous.
2. Germination — Days 2–4. Mist daily. Move to bright light once cotyledons appear.
3. Growth — Days 4–7. Keep misting. Strong light prevents legginess.
4. Harvest — Days 7–10. Cut at soil level with scissors. Use within hours for maximum flavour.

Keep at or above 15°C where the crop record sets a floor.

Harvest

First cut around 7–10 days.

Cut at soil level with scissors. Use within hours for maximum flavour.

Common mistakes

• Confusing with garden cress — White mustard and garden cress are different plants — often sold together as "mustard and cress." White mustard (Sinapis alba) has heart-shaped cotyledons. Cress (Lepidium sativum) has lobed leaves. Both are excellent micros.
• Growing too warm — Above 25°C, mustard micros grow leggy and develop a bitter edge. Keep at room temperature. A cool windowsill produces the best flavour.
• Letting them get too old — Past 12 days, the stems toughen and flavour turns bitter. Harvest at 7–10 days. Reseed immediately.

In the kitchen

• Classic mustard and cress — Pair with cress on buttered white bread — the traditional British combination.
• Cheese toastie upgrade — Pile onto a hot cheese toastie after grilling. The heat of the bread wilts them slightly.
• Ploughman's garnish — Add to a ploughman's plate alongside cheddar, pickle, and crusty bread.
• Egg mayonnaise — Fold into egg mayo with a squeeze of lemon. Classic.
• Steak topper — Pile dressed mustard micros on a resting steak — the peppery bite cuts through the fat.

Questions

Sources

1. White Mustard Seed Pack
2. Coco Soil treatise
3. HubWīk contents
4. Grower knowledge + RHS Growing Guides