Mustard greens are peppery oriental leaves, including mizuna and red-leaved mustards, valued for speedy, repeated pickings. Young leaves are mild enough for salads, while larger leaves give stir-fries more bite. They are particularly useful for cool-season allotment crops and protected winter growing.

When and how to sow

Sow thinly outdoors from late August into autumn in moist, fertile soil, or start an early crop under cover from February to March. Avoid midsummer sowing, when heat and long days encourage flowering. Cover autumn rows with a cloche where winters are severe. Thin seedlings to 10 to 20 cm apart, depending on whether you want baby leaves or larger plants.

Care

Water regularly during dry spells to keep leaves tender and discourage premature flowering. Work organic matter into the bed beforehand, keep weeds down and sow short rows at intervals for a continuing supply. In colder districts, fleece, a cloche or polytunnel makes winter picking far more reliable.

Common problems

Flea beetles commonly pepper leaves with small holes, especially on warm, dry days. Fine fleece over seedlings gives effective protection. Slugs can damage tender growth, and crowded, damp plants may develop leaf spotting. Space plants well, water the soil rather than foliage, remove affected leaves and rotate brassica-family crops.

Harvest

Begin cutting young leaves once they are large enough to use, taking only a little from each plant for repeated harvests. Leaves are mildest when small and become hotter as they mature. Pick regularly before flower stems form, especially during bright spring weather, and use fresh growth first.

Growing Mustard Greens: frequently asked questions

When should I sow mustard greens in the UK?

Sow thinly outdoors from late August into autumn in moist, fertile soil, or start an early crop under cover from February to March.

What are common problems when growing mustard greens?

Flea beetles commonly pepper leaves with small holes, especially on warm, dry days.

When is mustard greens ready to harvest?

Begin cutting young leaves once they are large enough to use, taking only a little from each plant for repeated harvests.

General guidance for UK home gardens and allotments. Reference figures are typical values; your exact timing depends on your region, last-frost date and variety. Page updated 19 Sep 2026.