How Long Does Radish Take to Grow? A Quick Guide to Fast Garden Harvests
Introduction
Radishes are one of the fastest and easiest vegetables to grow, making them ideal for beginners and experienced gardeners alike. Whether you’re sowing in containers, raised beds, or rows on the allotment, radishes reward you with crunchy, peppery harvests in no time.
But just how long do radishes take to grow? And what factors can speed up—or slow down—their development?
In this guide, we’ll explore how long radishes take to grow from seed to harvest, the different timelines for spring and winter radish varieties, and the best tips for a successful, speedy crop.
How Long Do Radishes Take to Grow?
Most spring radishes are ready to harvest in 21–30 days after sowing—just 3 to 4 weeks! These quick growers make them perfect for succession planting and instant gratification in the garden.
Growth timelines by type:
| Radish Type | Time to Maturity | Best Season |
|---|---|---|
| Cherry Belle | 21–25 days | Spring to early summer |
| French Breakfast | 25–30 days | Spring and autumn |
| Daikon/Mooli | 50–70 days | Late summer to autumn |
| Watermelon Radish | 60–75 days | Late summer to autumn |
| Black Spanish | 55–80 days | Autumn and winter |
👉 Quick tip: Always check your seed packet for exact maturity estimates.
Radish Growth Stages (Week by Week)
Week 1: Germination
- Radish seeds germinate within 3–7 days in moist soil
- Ideal temperature: 10–25°C (50–77°F)
- You’ll see small green shoots emerge quickly
Week 2: Leaf Growth
- True leaves form after the seed leaves (cotyledons)
- Plants focus on building a small canopy of foliage
Week 3: Root Formation
- Energy shifts to the swelling of the root beneath the soil
- Shoulders of the radish may become visible at soil level
Week 4: Harvest Time
- Small globe radishes will be firm, round, and ready to pull
- For larger varieties, continue growing another few weeks
Factors That Affect Radish Growth Speed
🌡️ Temperature
- Ideal: 10–20°C
- Too hot = bolting
- Too cold = slow growth
☀️ Sunlight
- Needs 6+ hours of sun per day
- Partial shade tolerated, but roots may develop more slowly
💧 Watering
- Keep soil consistently moist, not waterlogged
- Irregular watering can cause split roots or poor bulb formation
🌱 Soil
- Well-drained, light, loose soil is best
- Avoid compacted or clay-heavy soil—radishes need space to expand
🧪 Fertilisation
- Too much nitrogen = all leaves, no roots
- Add compost or a balanced organic fertiliser before planting
How to Speed Up Radish Growth
Want to grow radishes even faster? Try these proven tips:
- Pre-soak seeds for 4–6 hours to jumpstart germination
- Cover beds with fleece or cloches to warm soil early in spring
- Use fine compost or sandy soil for less resistance
- Water evenly and frequently
- Sow little and often for continuous harvests
Under ideal conditions, some fast varieties like ‘Sparkler’ or ‘Cherry Belle’ can be harvested in just 20 days!
Can You Grow Radishes All Year Round?
Radishes grow best in cool weather. In the UK and similar climates:
✅ Best growing periods:
- March–June (spring sowing)
- August–September (autumn sowing)
🚫 Avoid:
- Mid-summer sowings – high heat causes bolting and poor root development
- Heavy winter frosts – will slow growth unless under cover
To grow all year:
- Use cold frames, greenhouses, or polytunnels
- Sow winter radish varieties in late summer for harvest in late autumn
When to Harvest (by Type)
| Variety | Time from Sowing | Signs It’s Ready |
|---|---|---|
| Cherry Belle | 21–25 days | Bright red, round root at soil surface |
| French Breakfast | 25–30 days | Cylindrical with white tips visible |
| Daikon (Mooli) | 50–70 days | Long white root above ground, firm |
| Watermelon Radish | 60–75 days | Green skin, pink flesh inside—check by lifting slightly |
| Black Spanish | 55–80 days | Round black root, firm texture |
Always pick before they get woody or start bolting.
Common Radish Growing Problems (and Fixes)
| Problem | Cause | Solution |
|---|---|---|
| All leaves, no root | Too much nitrogen, overcrowding | Thin seedlings, use balanced fertiliser |
| Small, stunted roots | Compacted soil, too little sunlight | Loosen soil, relocate to sunnier spot |
| Hollow roots | Over-mature, left too long | Harvest earlier |
| Cracked roots | Inconsistent watering | Water regularly and evenly |
| Bolting (flowering early) | Hot weather or plant stress | Sow in cooler months or use cloches |
Can You Eat Radishes Before They’re Fully Grown?
Yes! Young radishes are mild and tender, and you can harvest them early if you’re thinning rows or prefer baby vegetables.
In fact, microgreens grown from radish seeds are ready in just 7–10 days and are packed with peppery flavour and nutrients.
Re-Sowing for a Continuous Crop
To keep a steady harvest going:
- Sow new rows every 7–10 days during the growing season
- Harvest mature rows while younger ones develop
- This method is called succession planting and works brilliantly with radishes
Great for small spaces, containers, and raised beds.
Radishes: Fast Facts for Gardeners
- Fastest-growing vegetable in most gardens
- Can grow in window boxes, balcony pots, or direct in soil
- Great for kids’ gardening projects
- Help loosen compact soil when interplanted
- Attract pollinators when allowed to flower (great for seed saving too)
Conclusion
So, how long does a radish take to grow? Most spring types are ready in just 3–4 weeks, while larger or winter varieties take 50–80 days. With their quick turnaround and minimal fuss, radishes are a top choice for beginners, succession sowing, and early-season confidence boosters.
Whether you’re growing them for crunchy salads, roasted side dishes, or the satisfaction of seeing speedy results, radishes are a brilliant way to make your garden productive all season long.
Top 10 Questions and Answers About Growing Radishes
1. How long do radishes take to grow?
Most are ready in 21–30 days. Larger types like Daikon take 50–70 days.
2. Can radishes grow in 3 weeks?
Yes—especially fast varieties like ‘Cherry Belle’ under ideal conditions.
3. What month do you plant radishes?
March to June for spring crops, August to September for autumn crops.
4. Why are my radishes growing leaves but no bulbs?
Too much nitrogen, overcrowding, or not enough sun.
5. How do I know when a radish is ready to harvest?
Look for a visible shoulder above the soil, and feel for a firm, round root.
6. Can I grow radishes in pots?
Absolutely—just use deep enough containers and loose soil.
7. Do radishes regrow after harvesting?
No—the root is the harvested part. You’ll need to re-sow.
8. What is the fastest growing radish variety?
‘Cherry Belle’ and ‘Sparkler’—as quick as 20–22 days.
9. Can I grow radishes indoors or on a windowsill?
Yes—if there’s enough sun. Microgreens are ideal indoors.
10. Do I need to fertilise radishes?
Use compost or a balanced fertiliser—avoid too much nitrogen.