🫚 Celeriac 'Monarch'

Sowing window (UK)	February to March
Minimum soil temperature	10°C at seed depth
Spacing	40 cm apart
Days to germination	21 days
Days to harvest	180 days
Sowing method	Start under cover, transplant out
Frost hardy	No
Sun	full-sun
Watering	high
Plant family	Apiaceae

When should I sow Celeriac 'Monarch' in the UK?

In the UK, sow Celeriac 'Monarch' from February to March. It is normally started under cover and transplanted. Wait until the soil has reached 10°C at seed depth rather than going by the calendar - celeriac will sit and rot in cold ground.

What soil temperature does Celeriac 'Monarch' need to germinate?

Celeriac 'Monarch' needs a minimum soil temperature of 10°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 Celeriac 'Monarch'?

For Celeriac 'Monarch', space plants 40cm apart.

How long does Celeriac 'Monarch' take to grow?

Celeriac 'Monarch' takes roughly 180 days from sowing to harvest. Seed usually germinates in about 21 days.

Is Celeriac 'Monarch' frost hardy?

No. Celeriac 'Monarch' is not frost hardy. Do not put it outside until the risk of frost has passed in your area, and be ready to fleece it if a late frost is forecast.

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.