How to Grow Turnips USA | Companion Planting & Care

Brassica oleracea Capitata Group

Both crops are documented hosts of Club root. These pathogens persist in soil for many years -- RHS gives up to 20 years for club root resting spores, at least 15 years for allium white rot sclerotia, and advises a five-year gap before replanting onions or shallots after downy mildew -- so the two…

Brassica oleracea Gemmifera Group

Both crops are documented hosts of Club root. These pathogens persist in soil for many years -- RHS gives up to 20 years for club root resting spores, at least 15 years for allium white rot sclerotia, and advises a five-year gap before replanting onions or shallots after downy mildew -- so the two…

Raphanus sativus

Both crops are documented hosts of Club root. These pathogens persist in soil for many years -- RHS gives up to 20 years for club root resting spores, at least 15 years for allium white rot sclerotia, and advises a five-year gap before replanting onions or shallots after downy mildew -- so the two…

Brassica napus Napobrassica Group

Both crops are documented hosts of Club root. These pathogens persist in soil for many years -- RHS gives up to 20 years for club root resting spores, at least 15 years for allium white rot sclerotia, and advises a five-year gap before replanting onions or shallots after downy mildew -- so the two…

Brassica oleracea Acephala Group

Plasmodiophora brassicae produces resting spores that contaminate the soil and remain viable for many years, so any brassica following an infected crop is re-infected from the ground itself. Keep every brassica -- including radish, swede and turnip, which gardeners often forget are brassicas --…

Brassica oleracea Botrytis Group

Plasmodiophora brassicae produces resting spores that contaminate the soil and remain viable for many years, so any brassica following an infected crop is re-infected from the ground itself. Keep every brassica -- including radish, swede and turnip, which gardeners often forget are brassicas --…

Brassica oleracea Italica Group

Plasmodiophora brassicae produces resting spores that contaminate the soil and remain viable for many years, so any brassica following an infected crop is re-infected from the ground itself. Keep every brassica -- including radish, swede and turnip, which gardeners often forget are brassicas --…

Soil pH range

Span reflects genuine variation between the cited authorities, not a single agreed figure.

Plasmodiophora brassicae

RHS names turnips explicitly among club root hosts.

Delia radicum

RHS names turnip explicitly among affected root crops.

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

Covered by the RHS phrase "All edible brassicas".

Chrysomelidae: Alticini (various spp.)

Small chewing beetles with powerful hind legs that leap away when disturbed, shot-holing the leaves. Clemson notes they are "most problematic on mustard and turnips" -- the brassicas without the waxy leaf coating that…

deficiency

RHS: spring sowings germinate quickly and well, though hot, dry weather can reduce success. These lobed young leaves are also edible as a cut-and-come-again crop in their own right, separate from the root.

As the root bulks up it pushes above the soil line, colouring purple where it catches the light and staying white below -- a visible cue for judging size without pulling a plant to check.

RHS recommends lifting at golf-ball size for eating raw, or tennis-ball size for cooking. Left larger than that, or grown too slowly, the root turns woody and bitter rather than staying crisp.

Early varieties mature in around six weeks from sowing, maincrops in about ten -- turnip is a much faster crop than its relative swede, which takes up to six months.

RHS: autumn-harvested roots keep for several weeks in trays of moist coir or sand, in a cool, frost-free place -- useful for a crop that matures this quickly and would otherwise all be ready at once.