Root vegetables
Swede
Brassica napus subsp. rapifera
Timings for your region
Suggested: Moderate · Explained in the glossary
Sow outdoorsmid May – late June
Harvestmid September – mid November
Practical tip
Botanically a brassica — do not follow other brassicas in the same bed, or clubroot builds up.
Origin & history
The swede arose as a natural cross between turnip and cabbage, which makes it the same species as oilseed rape — just the form with a fat root instead of oily seed. It was first described in the 17th century from Scandinavia, hence the English name. In Germany the “Steckrübenwinter” of 1916/17 still clings to it, when it had to replace the failed potato harvest in the First World War; only in the last few years has it reappeared in veg boxes.
Varieties
Yellow-fleshed varieties like the classic “Wilhelmsburger” taste strong and sweet, white-fleshed ones stay milder and cook soft faster. Make sure you are buying a culinary and not a fodder variety — fodder types grow huge but coarse and fibrous. The range is almost entirely open-pollinated; if you have clubroot in the bed, look specifically for varieties described as clubroot-tolerant.
Care
Sow direct and then thin rigorously to 25 cm — leave the row standing and you harvest nothing but small roots. Water evenly: a lot of water after a dry spell splits the roots and makes them woody. Feed moderately, or you mostly grow foliage. That half the root sits above the soil is normal and no reason to earth it up.
What can go wrong
Clubroot is the one serious issue: foliage wilting at midday and knobbly, swollen roots whose resting spores stay in the soil for up to twenty years. It favours acidic, compacted wet ground — a free-draining bed and a pH around 7 lower the pressure, but rotation decides it: at least four years between it and cabbage, radish or mooli. Flea beetles shot-hole the seed leaves in dry warmth; keep the row moist and cover it with a fine mesh crop net, which at the same time shuts out cabbage root fly, whose maggots otherwise tunnel into the root.
Harvest, storage & kitchen
Harvest at 10 to 15 cm across — bigger roots go spongy and fibrous inside. A few light frosts make them sweeter, but bring them in before hard frost; twist off the leaves and pack them in damp sand in a cool cellar and they keep into spring. In the kitchen they do more than stew: diced and roasted, mashed together with potato, or finely grated raw in a salad.
All timings are guide values for the given climate, not a guarantee. Weather, aspect and variety all have a say.