Radishes are one of the easiest and quickest vegetables to grow, making them a favorite for impatient gardeners and children just starting out. From sowing to harvesting, radishes can be ready to eat in as little as 4-6 weeks!
But even though they grow quickly, it’s important to know when to transplant radish seedlings so you get a good crop. Transplant too early and the tender seedlings may struggle. You might not be able to eat your radish roots if you wait too long.
So when exactly should you transplant your radish seedlings? And what signs should you look for to know they are ready?
Here is a Step-By-Step Guide to Transplanting Radish Seedlings for the Best Results
1. Start Radish Seeds Indoors or in a Greenhouse
While you can sow radish seeds directly into the garden bed, starting them off indoors or in a greenhouse will give you stronger, healthier seedlings ready for transplanting outside.
Sow seeds 6mm deep in seed raising mix. Keep the soil moist and expect germination in 5-8 days. In seven to ten days, the seedlings will have true leaves. In two to three weeks, they will be ready to be moved.
2. Wait for Seedlings to Reach the Right Size
Don’t be tempted to transplant too early while the seedlings are still small and delicate This risks damaging the tender roots and slowing growth.
When the radish seedlings are about 10 to 15 cm tall and have their second true set of leaves, you can plant them. This means the seedling’s taproot is strong enough to handle being moved.
3. Harden Off Radish Seedlings Before Transplanting
About 1-2 weeks before you intend to transplant into the garden bed, start hardening off the seedlings. This toughens the plants up, helping them transition from the indoor conditions to the harsher outdoor environment.
To harden off, place seedlings outdoors in a sheltered spot for 1-2 hours. Bring them back indoors overnight. Gradually increase the time outside over 7-10 days until ready to remain outdoors overnight. Avoid transplanting on hot, sunny days.
4. Prepare the Garden Bed for Planting
Get the garden bed ready while you wait for the seedlings to be ready. Dig over the soil, removing weeds, stones and clumps. Put in aged compost or manure to help the soil drain better and get more nutrients.
Radishes prefer nutrient-rich, well-draining soil with a pH between 6.0 – 7.0. In heavy clay soil, raised garden beds enriched with compost work well.
5. Transplant on an Overcast, Cool Day
Once your radish seedlings are 10-15cm tall and hardened off, choose a mild, overcast day to transplant into the garden bed. Cool, cloudy conditions reduce transplant shock.
Water seedlings well the day before. Gently dig up seedlings trying to keep the soil and roots intact. Use a trowel to dig a hole to the same depth as the seedling plug.
6. Plant at the Same Depth as the Seedling Plug
When placing the radish seedling into the hole, be sure not to plant too deeply. Plant at the same soil depth the seedling was originally growing at in its container.
Backfill the hole gently but firmly around the roots with surrounding soil. Water transplants well to settle the soil and eliminate air pockets around the roots.
7. Provide Care and Regular Feeding
Proper aftercare ensures your transplanted radish seedlings establish well. Provide 1 inch of water per week and mulch around plants to retain moisture. Feed every 2-3 weeks with a balanced organic fertilizer.
Watch for pest and disease problems which are uncommon but can occasionally occur. Harvest radishes when roots reach 2.5-5cm diameter, around 4-6 weeks after transplanting.
Ideal Conditions for Growing Great Radishes
Now you know when and how to transplant radish seedlings, what about optimal growing conditions for a bountiful harvest? Here are some key tips:
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Sunlight: Radishes need at least 6 hours of full sunlight daily. Partial afternoon shade in hot summer climates.
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Soil temperature: 10°C minimum for germination. Best growth between 15-20°C.
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Soil pH: Ideal between 6.0-7.0. Add lime if too acidic.
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Soil: Loose, crumbly, nutrient rich soil high in organic matter for good drainage and root expansion.
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Watering: Keep soil moist but not waterlogged. Around 1 inch of water per week.
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Fertilizer: Apply balanced organic fertilizer every 2-3 weeks. Avoid excess nitrogen.
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Companion planting: Plant with carrots, beets, lettuce, peas, beans, cucumbers.
Follow these simple tips on when to transplant radish seedlings, and you’ll be rewarded with a bountiful harvest of sweet, crispy radishes in no time at all! Pay attention to seedling size, hardening off, and planting depth for the best results. And provide optimal sun, soil, water and nutrients as the plants mature.
With their speedy growth, radish are a fun, easy and fast-rewarding crop for kids and new gardeners. Not to mention a tasty addition fresh from the garden. So don’t delay – go out and get sowing and transplanting those radish seeds today!
