Turnips are fast-growing, dependable, and ideal for anyone wanting quick results on their allotment. They can be harvested young in as little as six weeks, or left to mature for larger roots. Hardy, productive, and low-maintenance, turnips thrive in most soils and provide greens as well as roots. This guide covers everything you need to grow sweet, tender turnips with minimal fuss.
Quick Facts
| Metric | Details |
|---|---|
| When to Sow | March to August |
| Germination Time | 7–14 days |
| Time to Harvest | 6–10 weeks |
| Ideal Soil | Light, fertile, moisture-retentive |
| Position | Full sun or partial shade |
| Spacing | 10cm apart, 25–30cm between rows |
Preparing the Soil
Turnips prefer fertile, well-drained soil but aren’t highly demanding.
Improve poor ground with compost, but avoid fresh manure — it encourages leafy tops and poor roots.
Remove stones and break up clods to prevent misshapen roots.
A slightly acidic to neutral pH (6.0–7.0) is ideal.
Sowing the Seeds
Turnips are always sown directly into the soil — they dislike transplanting.
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Create shallow drills 1–2cm deep
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Space rows 25–30cm apart
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Sow thinly and cover lightly with soil
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Water gently to settle the seeds
For continuous harvests, sow a small batch every 2–3 weeks from spring to late summer.
Baby Turnips
If you want tender baby turnips, sow closer together (5–8cm apart) and harvest early.
Watering and Feeding
Keep the soil consistently moist.
Dry soil leads to woody, spicy, or cracked roots.
Water 2–3 times a week in hot weather and mulch to retain moisture.
Turnips don’t need much feeding — too much nitrogen leads to lush leaves and tiny roots.
Thinning and Maintenance
Once seedlings reach 2–3cm tall, thin them to 10cm spacing (or less for baby turnips).
Thin in the evening to reduce stress and water immediately afterwards.
Weed regularly but avoid disturbing shallow roots.
Harvesting
Turnips mature quickly.
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Baby turnips: harvest at 4–6 weeks
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Standard varieties: 6–10 weeks
The ideal size is roughly tennis-ball sized — anything much bigger can become woody.
Gently pull by hand or loosen the soil first in dry conditions.
Turnip greens are also edible and excellent cooked or in stir-fries.
Common Problems and Solutions
| Problem | Cause | Solution |
|---|---|---|
| Woody or tough roots | Left too long / drought | Harvest earlier and water consistently |
| Flea beetles | Tiny holes in leaves | Use mesh covers; keep soil moist |
| Root maggot | Fly larvae tunnelling roots | Use insect mesh; practise rotation |
| Bolting | Hot, dry conditions | Sow earlier or later; keep soil moist |
Companion Planting Tips
Turnips grow well alongside:
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Peas and beans (add nitrogen back into soil)
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Onions
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Lettuce
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Spinach
Avoid planting near other brassicas in the same bed (cabbage, broccoli, kale) to reduce pest and disease buildup.
Using the Allotment Planner Tool
Add turnip rows to the Allotment Planner tool to plan tight spacing, quick succession sowings, and rotation with other brassicas.
Because they mature quickly, turnips are perfect for filling gaps on your plot — the planner helps you maximise every inch.
FAQs
When should I sow turnips?
Any time from March to August, depending on whether you want spring, summer or autumn harvests.
Why are my turnips woody?
Usually because they were left too long or didn’t get enough water.
Do turnips grow in shade?
Partial shade is fine, especially in summer.
Can I eat the leaves?
Yes — turnip greens are nutritious and very tasty when cooked.
What are the best varieties for allotments?
‘Purple Top Milan’, ‘Tokyo Cross’, and ‘Snowball’ are consistent, reliable choices.