Swede Growing Guide: from seed to kitchen
Swede Growing Guide
The essential guide to growing swede from seed (Brassica napus); with notes on germination, cultivation, harvest and even kitchen uses. Also known as rutabaga or Swedish turnip.
Meet the Swede Family:
- Purple-top yellow-flesh – classic market type, purple shoulders, golden interior, sweet-nutty flavour that roasts or mashes to a buttery finish. See Aspen Purple Top.
- Green-top white-flesh – paler skin, milder taste; perfect grated raw into salads or for creamy gratins where its colour stays light.
- All-yellow heirlooms – skin and flesh both deep orange, with richer carrot-like sweetness; shine in soups, pasties, rival mashed potato and winter purées. See Tasmanian Butter Swede.
Seeds per gram: 300 – 400 seeds
Optimal germination: 16 – 28 °C; emergence in 7 – 14 days
Feed requirements:
- Moderate.
- Spread 2-3 cm of of compost plus a light dusting of balanced organic fertiliser across the bed and dig/fork in.
- Excess nitrogen gives big tops and woody roots.
Growing Notes:
Climate & timing
- Sow mid-summer to early autumn for harvest through winter–spring (about 90 days to maturity).
- In cool districts a late-spring sowing also works for early autumn eating.
Sowing & spacing
- Direct-sow 5-8 mm deep.
- Thin once 4 true leaves to 20-30 cm between plants in rows 30–50 cm apart; crowded seedlings stay small.
- Swedes like slightly acidic soil (pH 6–7) and steady moisture.
Care
- Mulch to maintain even soil humidity—irregular watering causes splits.
- Thinning to 20-30 cm between plants in rows is essential to prevent small roots.
- A one-off boron drench (1 Tbsp borax in 5 L water) at 5 cm tall prevents brown hollows caused by deficiency.
Common Problems:
- Cabbage Moth - Net young rows against cabbage moth; spray Bt (Dipel) at first sign of larvae.
- Flea beetles & aphids – exclude with fine mesh; spray eco-oil if needed.
- Powdery mildew or downy leaf spots – improve airflow, water at soil level. Remove old leaves.
Harvesting & Storage:
- Roots taste sweetest after a couple of frosts.
- Roots store well in the ground through winter, so pull as required.
- Lift the lot when days lengthen and warmth returns.
- Loosen soil with a fork, lift by the crown, trim leaves to 2 cm.
- Store in fridge.
Enjoy swedes mashed with butter and white pepper, cubed in casseroles or grated fresh for a crunchy twist—one seed delivers a whole season of versatile winter comfort food.