Growing Radishes from Seed, Everything You Need to Know

If you are a new at gardening or you want something your kids can grow, try growing radishes from seed. They are easy to grow perfect for the new gardener. And they grow quickly making them the perfect first vegetable for kids to grow too.

Growing radishes from seed is fairly easy, but here’s everything you need to know to successfully grow them in your backyard garden.

Growing radishes from seed

The Easiest Varieties of Radishes to Grow in Your Backyard Garden

I’ve tried a few different radishes to grow, and some grow easier than others. Or at least it seems that way. Here’s a few of the easier ones to grow if you are new to gardening.

Scarlet Globe, I’ve had good success with this variety of radishes. It makes nice red globe radishes. Perfect for salads.

French Breakfast is another variety I’ve had good success with too. They are elongated in shape and have a more peppery flavor too. They are really quite tasty.

One Variety I Wanted to Grow But…

Watermelon Radish is a variety that takes longer to harvest and I was really hopeful about. But every time I’ve grown it we’ve never gotten an edible one.

Now that could have been because of the warmer weather or I left them too long. But I’ve tried three separate times and never got a good radish.

It is a pretty radish white on the outside and pink on the inside. If you live in an area with a nice long spring, this might be perfect for your garden. In our garden it has been a flop.

Maybe because we can have unpredictably warm spring days off and on.

Radish seedlings growing good

Growing Radishes, When and Where to Plant

What is the growing season for radishes?

The best time to grow radishes is in the spring when the ground can first be worked. To keep a consistent harvest of radishes coming be sure to plant more every 10-14 days, until the weather warms to about 65 degrees.

Once it gets that warm it’s time to quit planting radishes until late summer when the weather cools off again.

You can plant spring and winter varieties of radishes in late summer for a fall harvest.

Best Location to Grow Radishes

Where should I plant my radishes?

Radishes should be planted in light, well-drained soil in an area that gets at least 6 hours of sun a day. If you are planting longer varieties of radishes be sure to till the soil to about 8 inches deep.

Radishes growing in our backyard garden

Planting Radishes, What You Need to Know to Help Them Thrive

Planting Radishes

You can plant radishes in rows or if you are square foot gardening, you can plant 16 seeds per square foot. If planting in rows thin so there is about 1-2 inches between plants for plenty of room for bulbs to form.

There is no need to have a full section of the garden for radishes. You can plant them in empty spaces around the garden beds.

You can tuck them in around slower growing vegetables like, broccoli seeds. Since the radishes will grow more quickly and then harvested that will leave the room for the slower growing vegetables.

What do you plant after radishes?

If you have a full section in the garden for radishes, you can grow a warm weather crop after them. Good vegetables to plant after radishes are beans, tomatoes, squash, or melons.

How long does it take to grow radishes from seed?

Radishes grow fast. They are one of the fastest growing vegetables. They are great for kids to grow because from seed to harvest is only about 4 weeks. Some varieties can be ready in 21 days. Perfect for kids or beginner gardeners.

Watering Radishes

How much water does a radish seed need to germinate?

The seeds need to be kept moist until they germinate about 5-10 days. Once the seedlings are up, thin to 1-2 inches part.

Once the plants are growing consistent watering is needed at about 1 inch per week. Try to not give a bunch of water at one time as it can make the bulbs split.

Feeding Radishes

Radishes need little in the way of fertilizer. In fact, too much nitrogen can cause thin, spindly radish roots, less flavor, and overgrown tops.

If you need to add anything add a small amount of all purpose fertilizer to the soil and work it in before planting.

One of the radishes grown from seed from our garden.

Harvesting Radishes

When should you harvest radishes?

You should harvest spring planted radishes when they become an useable size. Don’t let them sit in the ground that will only result in spongy and spicy radishes. For spring planted radishes it’s best to pick them before the root is 1 inch in diameter.

For radishes planted in late summer, they should be harvested in the fall. The late summer radishes grow more slowly and can tolerate being in the ground longer without becoming spongy and spicy. You can let the fall-planted radishes get a little bigger before harvesting them.

How to Harvest Radishes

When harvesting radishes pull them up and out of the ground straight up. So you don’t disturb the remaining radishes nearby.

Radishes grown from seed in our garden

Growing Radishes Problems

Why are my radishes growing long and thin?

If your radishes are growing long and thin there could be a couple of things happening.

It could be the weather is just too hot. This has happened so many times.

When the weather turns warm, the radishes won’t form bulbs, instead they go to seed. Unless you’ll be harvesting the seed, it’s better to pull them and move on.

Another cause could be the radishes are planted too close together, and the overcrowding is preventing the bulbs from forming. Be sure to leave about 1-2 inches between each plant. To ensure each plant has enough room to form a nice bulb.

Why are my radishes spicy?

Radishes that are left to grow too long, or they grew too slowly will get spicy.

Radishes like cool weather and need time to fill out before the weather gets too hot. Planting in early spring and harvesting them as soon as they reach a mature size will help to keep them from getting too spicy.

Why do radishes crack open?

This is something we deal with here in the Pacific NW, split radishes and carrots. It’s from uneven watering. Because of the amount of rain we get at one time in the spring we can end up with split radishes.

To prevent cracked radishes, it’s best to water about 1 inch of water a week. Add a little of water at a time over the full week. Too much water at one time can split the radishes.

Why do radishes get tough or woody?

This is something I deal with often. Just when I think we will have a nice cool spring so I can grow radishes the weather in May turns and feels more like August than May. Which can affect radishes.

Radishes need to grow quickly and need cool temperatures with regular water. If they don’t get what they need, they won’t grow properly. Which can make a gardener leave them in the ground longer hoping to salvage them. But that only leads to them getting tough and woody.

The longer they are in the ground the tougher they can get. It’s better just to pull them because once they turn woody or tough there is no going back.

A bundle of radishes grown from seed.

Those are all the facts you need for growing radishes from seed. They are easy to grow and fast growing too. A perfect vegetable to get you started on a backyard vegetable garden.

Now you know how to grow radishes here are a few ideas on how to prepare them for eating too.

More Growing Guides to Help You Grow More in Your Backyard Garden…

How to Grow Lettuce
How to Grow Peas
How to Grow Tomatoes

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