Sowing window (UK)March to September
Minimum soil temperature5°C at seed depth
Sowing depth1 cm
Spacing25 cm apart
Days to germination5 days
Days to harvest30 days
Sowing methodDirect sow outdoors
Frost hardyYes
Sunpartial-shade
Wateringmoderate
Plant familyBrassicaceae

When should I sow Mustard 'Red Giant' in the UK?

In the UK, sow Mustard 'Red Giant' from March to September. It is normally sown direct outdoors. Wait until the soil has reached 5°C at seed depth rather than going by the calendar - mustard will sit and rot in cold ground.

What soil temperature does Mustard 'Red Giant' need to germinate?

Mustard 'Red Giant' needs a minimum soil temperature of 5°C at seed depth to germinate reliably. Below that, germination is slow and patchy, and seed is more likely to rot than sprout. Measure at around 5cm down, in the morning, rather than trusting air temperature.

How deep and how far apart should I sow Mustard 'Red Giant'?

For Mustard 'Red Giant', sow it 1cm deep and space plants 25cm apart.

How long does Mustard 'Red Giant' take to grow?

Mustard 'Red Giant' takes roughly 30 days from sowing to harvest. Seed usually germinates in about 5 days.

Is Mustard 'Red Giant' frost hardy?

Yes. Mustard 'Red Giant' is frost hardy and will stand through UK frosts, so it can be left out over winter in most of the country.

Sowing data cross-checked against RHS growing guides and UK seed-merchant catalogues. Soil temperatures are the minimum for reliable germination, measured at seed depth.