Turnip

Turnip (Brassica rapa subsp. rapa), called shalgam across Pakistan, is the dual-purpose rabi root that turns up in every winter sabzi market and is fed to dairy buffalo on the side. POWO records the species as native through the central and eastern Mediterranean east to Iran and the Arabian Peninsula, so it sits squarely in Pakistan’s natural climatic envelope.¹ For a food-forest plot it is one of the most forgiving cool-season root crops a beginner can plant.²

Where it thrives

Turnip is a cool-season crop, cold hardy, and frost-improved — exposure to a light frost actually sweetens the root.² Sow as a rabi crop in the Punjab plains and Sindh from October through November, and earlier in late September on the Pothohar plateau or KPK hills where the season is shorter.³ It prefers a slightly acidic to slightly basic loam at pH 6.0 to 7.5, with steady moisture; drought stress makes roots bitter and woody.² Heat above about 25 degrees Celsius drives the plant to bolt and lose root quality, so the bulk of the crop runs through the winter window only.

Role in the system

Turnip sits in the groundcover layer as a pioneer, cool-season annual. The taproot pushes through compaction and brings nutrients up from the subsoil, which fits the role of a soil-opener in a young food forest. Tops left in place after harvest break down quickly into soil organic matter, and any roots not harvested rot in place to feed the next bed. It is not nitrogen-fixing, so pair it in the bed with a legume neighbour. As a brassica it slots into the same rotation block as cabbage, cauliflower and mustard, and must move out of that block for two seasons after to break clubroot and cabbage maggot cycles.²

Growing it

Decisions worth getting right. Direct-sow seed one to two cm deep into a well-worked bed; transplants are not standard for turnips. Space seed one to two inches apart in rows 18 to 30 inches apart, then thin to three to six inches between plants once true leaves appear.² Roots are at peak quality when about 2 inches across, so harvest small and harvest often rather than letting the bed run to oversized woody roots.³ Water consistently; uneven moisture splits roots and toughens leaves. Watch for flea beetle on young seedlings and cabbage maggot tunneling in the root; both respond to row cover early and to rotating brassicas off the bed.²

What you get

A well-managed rabi crop yields 15 to 30 tonnes per hectare of roots plus a heavy cut of leafy tops, on a 50 to 70 day cycle. Roots go into shalgam gosht, pickle, sabzi, and as the classic Punjabi mix with carrot and cauliflower; tops eat as saag. A systematic phytochemical review records 19 glucosinolates, 33 glucosinolate-breakdown products, and 59 polyphenolic compounds across turnip greens, with gluconapin and glucobrassicanapin dominant, plus a meaningful calcium load — 100 to 200 g of greens meets daily calcium reference intakes.⁴ Surplus roots and tops are good winter fodder for buffalo and goats.

Sourcing notes

Buy fresh open-pollinated seed from a reputable supplier each season; turnip seed loses vigour quickly in store. Good companions are bushing herbs that confuse flea beetle, and a nearby legume such as berseem clover or chickpea to offset nutrient draw. Keep turnip out of any bed that grew brassicas in the two prior seasons.

Sources

1. Royal Botanic Gardens, Kew (2024). “Brassica rapa L.” Plants of the World Online.
2. University of Minnesota Extension (2023). “Growing turnips and rutabagas in home gardens.” University of Minnesota Extension.
3. NC State Extension (2024). “Brassica rapa Rapifera Group (Turnips).” North Carolina Extension Gardener Plant Toolbox.
4. Paul, S. et al. (2021). “Phytochemical characterization of turnip greens (Brassica rapa ssp. rapa): A systematic review.” PLoS One.