Sowing Turnip Seeds for Container Growing: Modules, Fiber Pots & Early Care

My first turnip attempt used the heritage variety 'Manchester Market' (Thompson & Morgan), also known as 'Green Top Stone' for its pale green shoulders and creamy white globe roots. The packet contains ~750 seeds—far more than my container space allows. Sowing windows: mid-June to July for larger roots; August–September for smaller roots and edible greens. I sowed in July, just as weather turned wet and windy.

Variety Overview

• Position: Full sun
• Soil: Rich, fertile
• Ideal for: Kitchen garden
• Hardiness: Hardy
• Sowing months: June–September
• Harvest months: September–December
• Height/Spread: 25 cm (10 in)

Note: August–early September sowings yield smaller roots but nutritious greens.

Sowing in Cell Modules

I made two sowings a day apart to compare containers: a Gardman 36-cell windowsill kit (with base and clear lid for humidity) and biodegradable fiber pots. Modules were filled with firm, pre-watered John Innes No. 1 compost. Seeds sown shallowly—just 1 cm (½ in) deep—two per cell, lightly covered. The lid acts as a mini-greenhouse for germination.

Testing Biodegradable Fiber Pots

Fiber pots stay damp and lack rigidity compared to plastic. Their advantage: no root disturbance at transplanting—plant the whole pot, and roots grow through the degrading fiber. Tear the base open if needed. Worth testing, but I prefer sturdy plastic for handling.

Fine-Mist Watering

To avoid overwatering and displacing seeds, I used a spray bottle on fine mist setting instead of a watering can. Keeps compost evenly moist without disturbing germination.

Rapid Germination

First shoots appeared at 3 days (plastic modules) and 4 days (fiber pots). Two seeds per cell allowed thinning to the strongest.

Thinning with Blunt Tweezers

Blunt-ended tweezers gently remove unwanted seedlings. Firm soil around the keeper with the other hand to minimize root disturbance. Damp soil makes this easier.

Video: Sowing and Growing Turnips

Early Growth and Next Steps

Seedlings grew outdoors from the start, moving into the polytunnel overnight and during heavy rain. Once they outgrow modules, I'll pot them into grow bags to test container viability for this root crop.

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