How to Grow Siberian Kale

At a Glance

Quick Facts

Factor	Value
Soil texture	fertile soil (RHS)
Drainage	well-drained
Lifecycle	annual or biennial grown as an annual
Edible parts	leaves

Soil & Growing Conditions

Water: keep well-watered (RHS); benefits from compost or nitrogen-rich fertiliser worked in before planting (Properly Rooted)

Growth Stages

Stage	BBCH	Notes
Sowing	0	Sow indoors mid-spring, prick out to modules or individual pots (RHS); or direct sow after last frost up to six weeks before first frost (Properly Rooted).
Transplanting	1	Transplant out early summer, May-July, in rows 60cm apart (RHS).
Low, clustered leaf growth	3	Grows low and clustered, closer to the ground, rather than from a central stalk like most kale; keep well-watered and net against birds and insects (Properly Rooted, RHS).
Cut-and-come-again harvest	8	Harvest leaves at any size with a sharp knife; exceptionally cold-hardy, down to 10°F, mature plants to -20°F (Properly Rooted).

Harvest & Storage

When to pick: Harvest leaves at any size, from baby to full-grown, cutting with a sharp knife (Properly Rooted). Exceptionally cold-hardy: hardy down to 10°F, mature plants may withstand as low as -20°F (Properly Rooted).

Diseases

Brassica downy mildew

moderate

Hyaloperonospora brassicae (syn. Peronospora parasitica)

RHS names this directly for the Pabularia Group.

Club root

moderate

Plasmodiophora brassicae

RHS names this directly for the Pabularia Group: club root.

Pests

Aphids

low

Aphididae (various spp.)

Properly Rooted names this directly: aphids.

Cabbage caterpillars

moderate

Pieris brassicae; Pieris rapae; Pieris napi; Mamestra brassicae; Plutella xylostella

RHS names this directly for the Pabularia Group: cabbage caterpillars.

Flea beetles

moderate

Chrysomelidae: Alticini (various spp.)

RHS names this directly for the Pabularia Group: flea beetle.

Sources

1. Properly Rooted - Siberian Kale: A Primer

   A secondary gardening reference rather than a university or horticultural authority, used for growth-habit and hardiness detail specific to Siberian (not Red Russian), not contradicted by the above. Siberian kale produces wide, flat leaves growing closer to the ground, forming a low cluster rather than growing from a central stalk like most other kale. Exceptionally cold-hardy: hardy down to 10°F, mature plants may withstand as low as -20°F; less heat-tolerant than other kale types. Direct sow after last frost up to six weeks before first frost, or start indoors. Benefits from compost or nitrogen-rich fertiliser worked into the soil before planting. Harvest leaves at any size with a sharp knife. Fewer pest/disease problems than other kale types, but still susceptible to aphids, whiteflies, cabbageworm and cabbage looper.

2. Seed Ambassadors Project - All About Russian and Siberian Kale (napus kale)

   A specialist seed-heritage source, used for the specific leaf-colour/shape distinction between Siberian and Red Russian that RHS's Group-level page does not draw out (RHS bundles both under one Pabularia Group page); not contradicted by RHS. Red Russian and Siberian are the two most well-known named varieties of Russo-Siberian (Brassica napus) kale in the US, recognised as distinct cultivars, not interchangeable terms. Red Russian: stems and veins red/purple, leaves deep grey/green, flat with toothed edges, documented in Russia since 1885. Siberian (also "Early Siberian"): blue-green, huge, feather-shaped, slightly curled leaves, no red/purple pigmentation, extremely hardy, vigorous, rapid-growing. Both are recognised as genetically distinct parent stock -- modern crosses such as 'Red Ursa' deliberately combine "the broadleaf frills of Siberian with the colour of Red Russian," which would not make sense if they were the same plant.

These 2 sources are specific to this region. The full list of 3 sources behind this guide (Properly Rooted, Royal Horticultural Society, Seed Ambassadors Project) is in the references of our UK guide to siberian kale; they describe the plant itself, which is the same wherever it grows.