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Soil & potting mix

Best soil for 'January King' Cabbage (Brassica oleracea var. capitata 'January King')

Also called January King winter cabbage.

More about 'january king' cabbage

About 'January King' Cabbage

Brassica oleracea var. capitata 'January King' · also called January King winter cabbage · edible

January King is a classic, extremely hardy winter cabbage forming a dense, drum-shaped head with crinkled blue-green outer leaves flushed purple-red in cold. Sown in late spring, it stands in the ground through autumn and winter to harvest from late autumn into late winter. It needs full sun, firm fertile soil and a long, cool season, rewarding patience with a sweet, frost-kissed head.

Preferred mix: Rich, firm, moisture-retentive loam, pH 6.5-7.5

Watch for — Clubroot: Soil-borne disease swelling and rotting roots, stunting plants over the long season. Lime to near-neutral pH, improve drainage, and rotate brassicas on a 3-4 year cycle.

Why 'january king' cabbage needs this mix

'January King' Cabbage hates drying out, so it wants a mix that stays evenly moist — but it still needs perlite so "moist" never tips into "waterlogged".

For the full picture on what makes up a good mix, see our guide to the main types of soil and potting media — it explains why each ingredient above behaves the way it does.

What goes wrong with the wrong mix

The wrong soil is one of the most common reasons 'january king' cabbage struggles, and the damage often shows up weeks later as a watering problem. For this species specifically:

Using a sharp, fast-draining "houseplant" or cactus-leaning mix that lets 'january king' cabbage dry out. It needs a moisture-retentive but still airy blend.

pH — does it matter for 'january king' cabbage?

'January King' Cabbage prefers a slightly acidic mix (around pH 5.5-6.5); a peat-free compost-and-coir blend sits there naturally, so routine pH testing is unnecessary.

If you want to check or adjust it, the soil pH guide walks through testing and the safe ways to nudge a mix more acidic or more alkaline.

DIY mix vs a bagged one

A good peat-free houseplant compost works for 'january king' cabbage straight from the bag if you mix in some perlite for air. The DIY ratio above gives a more reliable moisture-to-air balance.

Drainage and the pot

Use a pot with a drainage hole but a less-porous material (plastic or glazed) so it does not dry too fast. Bottom-watering keeps the mix evenly moist without sogging the crown.

Peat-free mixes slump and compact as they hold moisture, so refresh 'january king' cabbage's mix every 12-18 months to keep air in the rootball even if the pot size is unchanged. When the time comes, our repotting guide for 'january king' cabbage covers the timing and technique step by step.

'January King' Cabbage soil — frequently asked questions

What is the best soil mix for 'january king' cabbage?

3 parts peat-free houseplant compost : 1 part coco coir : 1 part perlite. 'January King' Cabbage comes from damp, shaded forest floors and has fine roots that scorch and brown the moment the rootball dries — the mix has to hold a steady reserve.

Can I use normal potting soil for 'january king' cabbage?

A free-draining, gritty mix dries too fast for 'january king' cabbage — you get crispy brown edges and frond or leaf drop within days of one missed watering. A good peat-free houseplant compost works for 'january king' cabbage straight from the bag if you mix in some perlite for air. The DIY ratio above gives a more reliable moisture-to-air balance.

Does 'january king' cabbage need a special pH?

'January King' Cabbage prefers a slightly acidic mix (around pH 5.5-6.5); a peat-free compost-and-coir blend sits there naturally, so routine pH testing is unnecessary.

Should I buy a bagged mix or make my own for 'january king' cabbage?

A good peat-free houseplant compost works for 'january king' cabbage straight from the bag if you mix in some perlite for air. The DIY ratio above gives a more reliable moisture-to-air balance.

How often should I refresh the soil for 'january king' cabbage?

Peat-free mixes slump and compact as they hold moisture, so refresh 'january king' cabbage's mix every 12-18 months to keep air in the rootball even if the pot size is unchanged. Use a pot with a drainage hole but a less-porous material (plastic or glazed) so it does not dry too fast. Bottom-watering keeps the mix evenly moist without sogging the crown.

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