It's Radish Growing Time!

Radishes are one of the easiest plants to grow in the kitchen garden. They're the fastest and least-demanding of all the root crops, and that's saying something since root crops are mostly a plant-them-and-forget-them bunch. Some gardeners even claim radishes are the easiest plants to grow period, mostly because of their speed. 

If you're looking for a plant to increase your gardening success or to grow while you're dealing with a particularly busy calendar, radishes will give you a harvest without a whole lot of tending. Once they're planted, watered in, and thinned if needed, these little gals will mostly take care of themselves.

Plant radish seeds now and look forward to a quick gardening win in about a month!

My Favorite Radish Types to Grow

There are at least 100 different radish varieties (which is about 99 more varieties than you'll find available in the produce aisle of your grocery store), but here are my top picks to get you started.

French Breakfast Radish

This is, hands down, my favorite type of radish to grow. I had a couple disappointing seasons with radishes until I discovered this type, so if you're looking to grow radishes too, I highly recommend starting here. The roots don't grow very large, and they're ready in under 30 days.

Daikon Radish

I grew daikons in the fall in my raised beds, and they did really well. Size-wise, this type is on the opposite side of the spectrum from French breakfast radishes, so make sure you give them plenty of space to develop their long, white, carrot-like roots. They're also on the longer end of the time spectrum, requiring as many as 50 days to mature. Personally, I don't love the daikon radish taste—it's a little too peppery, but growing daikons is actually a great way to break up soil that's become too dense.

Watermelon Radish

This type wins the award for the prettiest to cut into. Watermelon radishes are sweet with only a mild pepper flavor. Instead of growing long like daikons, they'll grow wide, maxing out at about 4 inches in diameter. It'll take them 60 days to grow these delicious baseball-sized roots.

Cherry Belle Radish

This is your classic radish, the type you'd expect to find at the grocery store. In ideal conditions, you'll be able to harvest crunchy little roots that are about 1 inch wide in just 24 days.

Where to Sow Radish Seeds

Smaller radishes do really well grown in a container that's at least 12 inches deep. If you're wanting to grow a larger variety like daikon radishes, then you'll need a raised bed or container that's several inches deeper than the mature length of the radish root. Make sure your container has drainage holes so the roots don't sit in water.

Fill your raised bed or container with loose sandy loam soil (think equal parts organic topsoil, compost, and construction sand).

Make sure your radish plants will receive about 6 hours of direct sunlight each day. Radishes are pretty small plants that don't grow very tall above the soil, so avoid planting them somewhere they'll be in the shade of taller plants. If radishes are growing in shady spots, you might still get radish greens but not much by way of the actual root. And I'm guessing it's the root part you're most excited about.

I like to grow radishes as a border crop along the edge of my raised beds. I'll also plant an entire raised bed with fast-growing radishes.

When to Sow Radish Seeds

Radishes love cool weather and shorter days, which is why they're typically grown in the early spring and fall when temperatures range between 50 and 65 degrees Fahrenheit. If you live in a warmer climate, the best time to grow root crops like radishes might actually be during your winter months.

I plant mine when I have a period of temps between 35 and 65 degrees Fahrenheit. My goal is to plant radishes by seed 45 to 60 days before my last frost date in the spring and then again about 45 to 60 days before my first frost date in the fall. Radishes are pretty frost hardy (not like polar-vortex hardy, but a little frost or snow won't kill 'em), and I've even left mine uncovered during late snows in Chicago.

Root crops as a whole don't transplant well, so you'll wait to sow these seeds directly outdoors when the temps are right instead of starting radishes by seed indoors.

Let's get into the steps to sow radish seeds in your garden.

Check Your Soil Temperature

Use a simple temperature gauge to ensure your soil temperature is between 50 and 75 degrees Fahrenheit—the ideal soil temperature range for radishes. You can try to plant radishes outside of this range, but know that their days to harvest on the seed packet is for when they're grown under their preferred conditions.

Using a soil thermometer is a great way to determine whether it's too late or too early to plant something, but you also have a couple tools at your disposal to help regulate your soil temperature and extend your growing time a bit. During the transition from cold season to cool season, for example, you could use a frost cloth or cold frame when you first plant to protect young seedlings from frost.

If you're hoping for seeds to germinate at the end of your warm season before the transition into your cool season, you could use a shade cloth to protect your roots and cool the soil. Once the temperature drops a bit, you can remove the shade cloth and allow the plants to grow in the open air. 

Prepare the Planting Area

It's time to do a little something I think of as texture control. Basically, you want to loosen up your soil a bit but also grab any soil clumps and break them up by rubbing them in your palm. Use a hand rake to help you clean (as clean as soil can be, that is) and loosen the top couple inches of your soil. Remove any plant debris, rocks, and twigs—even small items can present challenges to baby radishes in the soil.

Ideally, your soil will hold most of its shape if you scoop up a handful but not feel too dense.

Radishes aren't heavy feeders, but I do like to add some compost and a little bit of earthworm castings to the top of the soil before planting for a little nutritional boost.

Avoid adding nitrogen-heavy fertilizers to the planting area. Too much nitrogen will encourage lots of leaf growth above the soil and not enough root growth below. On more than one occasion, I’ve watched lush, beautiful radish greens grow, only to pull my radishes and be thoroughly disappointed by the tiny roots underneath. 

Once you've added your amendments, use your hand rake to level the soil surface as best you can. You don't want your soil to be uneven when you're direct seeding, or one good rainstorm could displace all your seeds.

Sow Radish Seeds

You don't need any special tools to sow radish seeds, though certain tools can certainly help. In the picture, I'm using a dibber with 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.

Alternatively, you could use a trowel or hori hori to dig a little trench that's just 1/4 inch deep in the soil. I like to use stakes and twine to create a nice, straight line that I can trace with my hori hori so that my radishes will be planted in rows.

Whenever you're sowing seeds for a root crop, it's critical to space those seeds far enough apart to give each root room to grow to its full potential. Radish seeds are pretty small, and it's all too 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 to three inches (unless, of course, you're growing a larger radish). I often ignore the spacing guidelines on the back of seed packets, but here's an instance where it's a good idea to follow directions.

Do your best to place only one radish seed in each hole or every two inches or so down your trench. When you're planting the next row, place the seeds in the windows between the first set of seeds so that your rows are staggered.

Taking the time now to get your spacing right means you won't have to return and thin when you have too many baby radishes trying to grow in the same spot. I find thinning to be such a pain.

Cover Radish Seeds

Wait until all your seeds are sown to cover them up. That way you can make sure you haven't double-planted or skipped spots—though, to be honest, radish seeds are brownish and pretty hard to see against the soil.

Radish seeds are tiny, and the rule of thumb is the smaller the seed, the shallower you'll plant it. That means you barely need to cover them with soil. Buried too deep, they’ll struggle to reach the surface and might even die on their way to sunlight. I usually just pat the soil around them and sprinkle a little more compost or earthworm castings on top like fairy dust.

Water Your Radish Seeds

Keep your seeds well-watered. Basically, don't let the soil ever feel completely dry to the touch. Seeds for cool-season plants like radishes really like to stay moist as they begin to germinate. That means watering once a day until you see little green shoots pushing their way up. Once your radishes have sprouted, aim for about one inch of water a week.

Water carefully. Think gentle rainfall, not torrential downpour.

Come Back and Sow More Seeds

Radishes typically sprout in three to six days, which is pretty fast. After about ten days, you can replant areas where a seed failed to germinate.

Something you can also do is plant in stages so that you don't end up with a huge radish harvest all at once. Unfortunately, radishes don't keep as well as other root crops.

About two weeks after you've sown your first radish seeds, come back and plant another couple rows. This is called successive sowing. This method won't result in more crops to harvest overall, but it does result in a steady supply of roots over a longer period of time so that you don't have to figure out what to do with 200 radishes ASAP.

How to Care for Radish Plants

If you notice your seedlings are growing too close together, you'll need to thin them a bit. Learn more about how to thin and (potentially) replant your radish seedlings so that each and every baby radish has enough space to develop the part you want to eat. You can either pull the entire seedling up (and try to replant it) or cut the seedling at the base of the soil and eat the radish tops as you would microgreens.

Radish plants rarely need to be fertilized, but I like to add a little side dressing of fresh compost along the roots of my plants about two weeks after planting. This not only gives them extra nutrients, it also keeps their growing roots covered up, just the way they want to be until they're ready to be pulled.

You might notice that the radish greens resemble arugula leaves. They even have a similar peppery flavor. Radish tops are 100 percent edible, and you can actually harvest individual radish leaves as you wait for the roots to form.

If the weather gets too warm and your radishes bolt, here's how to save your own radish seeds for next season.

Mark Your Calendar for Radish Harvest Time!

Most radishes are ready around 45 days or so after planting by seed, but some need just 18 days! (Radishes are truly the garden's version of fast food.) Check the back of the seed packet for the radish variety you're growing to see how many days you'll have to wait before you can pull these little roots from the ground, and then set yourself a phone reminder or mark your calendar to hop outside and start checking on their progress.

Remember that if your weather hasn't cooperated, you could be looking at a little bit longer. Here are three signs that your radishes are ready to be harvested from the garden. You can always pull one radish and see if the roots have had time to form.

If you wait too long to harvest your radishes, they can become a little too big and either peppery or starchy. I've got three ways you can salvage them and still enjoy what you've grown.

Don't forget that you can eat the leafy tops too. When you grow your own veggies, you get to enjoy more parts of the plant than when you only eat what's stocked at the grocery store.

Try to enjoy both the radish roots and the leaves right away. Homegrown radishes wilt and lose their crispness pretty quick. Slice them up and eat them fresh, pickle them, or roast them in a little olive oil and salt just like you would a potato. So yummy!

One more thing: If you're craving radishes when the weather isn't right to grow your own, consider growing radish sprouts or radish microgreens indoors.

Thanks for helping me make gardening ordinary again!