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 while they are fast growing, getting the timing right for transplanting radish seedlings is important to ensure you get a good crop. Transplant too early and the tender seedlings may struggle. Leave it too late and your radish roots may end up woody and inedible.
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. Once true leaves appear in 7-10 days, your seedlings will be ready for transplanting in 2-3 weeks.
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.
Wait until the radish seedlings are around 10-15cm tall and have developed their second true set of leaves. This is a sign the seedling taproot is nice and strong, and able 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
While you are waiting for the seedlings to be ready, prepare the garden bed. Dig over the soil, removing weeds, stones and clumps. Mix in aged compost or manure to improve nutrients and drainage.
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!
Thinning Radishes Is a Pain
Thinning plants is one of those tasks that feels so hard. Here youve gone through all that effort to plant something, youve watched these little plant babies grow, and now youre just supposed to, what… pull some of them up?
I dont know about you, but thinning plants to me feels like a moral dilemma: the plants you pull will die, but if you dont pull some, none of your plants will have the room they need to grow to their fullest potential.
Fortunately, Ive found a way around this dilemma. I just replant the little guys Ive thinned, even though most professional gardeners will tell you not to do that. Its a gamble, but Ive had pretty good luck saving my plants that have fallen victim to thinning.
Lets explore how to make the most of every single one of the seeds youve planted. With any luck, youll get extra radishes out of the deal!
How can you avoid having to thin radishes in the first place?
Whenever youre sowing seeds for a root crop like radishes, its critical to space those seeds far enough apart to give each root room to grow to its full potential. Radish seeds are fairly small, and its easy to go the lazy route and scatter them about or plant them in rows too close together.
The ideal spacing between each radish seed is about two inches (unless, of course, youre growing a larger radish like a daikon). Its a good idea to check the back of the seed packet for how large each taproot is expected to grow and what the seed companys spacing recommendations are.
There are a couple gardening tools that can help you follow the seed spacing guidelines. In the picture below, you can see the dibber I use to help me plant radish seeds. It has 4 points spaced perfectly for planting small radishes (2 inches apart). You can use a similar tool to press very lightly into the soil to create shallow holes.
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FAQ
Do radish seedlings transplant well?
The perfect time to transplant radish is during early to mid-spring, as it ensures a thriving growth in optimal conditions. Choose a sunny, well-drained location and provide ample space. If needed, consider transplanting under protection, such as cloches, for best results.
When to transplant radish seedlings in pots?
Once seedlings reach 3-4cm tall, fill chosen pots with quality potting mix, such as Yates Potting Mix with Dynamic Lifter. Transplant seedling into pot and water in well with Yates Thrive Vegie & Herb Liquid Plant Food.
When to separate radish seedlings?
Radish seedlings should be thinned when they are about 2 inches tall, or approximately one week old. This allows for proper spacing and prevents overcrowding, which can lead to small, inedible roots.
What should you not plant radishes next to?
They could have a difficult time germinating and growing near other brassicas, so avoid planting radishes near broccoli, cabbage, cauliflower, turnip, and mustard. Avoid hyssop, a flowering plant that attracts many pollinators and beneficial insects, as it inhibits the growth of radishes.