How to Grow Radishes: A Complete Guide

Ed Wike
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Radishes: Quick Care Guide

Straw-colored tops, cone-shaped and pungent roots. What makes radishes such a popular vegetable is their crisp, piquant bite. This sharp flavor finds its use in a variety of dishes, especially as a garnish. Radishes also go well with roast meats and cheeses … and perhaps a dollop of butter.

Radishes are a resilient vegetable crop, which is easy to grow indoors or outdoors. The key to growing radishes is to make sure that they get regular water in order to grow quickly. It is also important to plant them on time, which will help them get the size required to supply you with edible root.

Read on to discover the complete guide to growing radishes at home.

Some of the varieties popular for commercial production include: Red Meat, Cherry Belle, Black Spanish, Spicylent, White Icicle, White Wonder, White Icicle Laylo, All Season, Champion, Festival, White Icicle Wolf, American Flag, Sabel, Black Spanish Heat Wave, Allivette, Apollo, Champion, Cherry Belle, Osterly, and Regal.

Standard Radishes

Radishes have a crisp texture and a very pungent taste that may be a bit too strong for some people to consume.

If you have kids who like to crunch entire radishes, then buying these radishes might be more economical than letting the kids pick out a design, because whole radish seeds are cheaper than radish seeds that have elaborate patterns or designs on them.

However, if you have picky eaters that won’t touch radishes or prefer radishes that are milder, then getting the regular variety of radishes with no pattern or design will be the way to go. When you want to add an extra touch of color to your salad, there is nothing like a red or purple radish that you can grate and put on top, thus adding a very attractive color to your dish.

The basic design for radishes is the big round red radish that has a tiny little round green top on it. It is a very typical design, but there are other shapes and designs available as well.

You can find radishes that are long and thin in shape instead. Some radishes have their skin on the inside, which is good for picky eaters who don’t like the skin. You can also find varieties of radishes that have a green top. These radishes are called Easter radishes or Cinderella radishes.

Daikon-Type Radishes

Unusual Radishes

The most common radish cultivars sold in grocery stores look like small potatoes. If you're looking to grow radishes with a larger root, you can purchase them as well. The most common are the Cherry Belle radish, the White Icicle radish, and the Elephant Garlic. The Green Cherry Belle radish pictured on the left is ready to harvest in 35 days and peaks at 1.5 inches in diameter.

Planting Radishes

If you are growing radishes, you will have to handle them a lot. Your fingers will be in and out of the soil and the holes quite often, so wear gloves. And you will get dirty, so wear old clothes.

When you plant radishes, space the rows a bit bigger than the radish. They like a looser soil, so give them some room.

If you sow directly in the ground, be sure to wait until the soil temperature is at least 60 degrees.

When To Plant Radishes

Radishes are one of those garden vegetables that can serve as a perfect introduction to a young gardener. They are easy to grow, and provide great success for even the most novice gardeners. You don’t have to worry too much about whether they will grow or not, and they’re ready to harvest in about 30 days from planting.

To have the best possible results with radishes, make sure you plant them when the ground is moist. It won’t hurt to add a generous dose of compost or well-aged animal manure to the soil before planting. If you’ve ever worked in soil directly after a rain, you will know it’s the most perfect time to plant. Time your planting so you will be able to harvest radish roots just before they flower. Radishes will grow just fine in the cooler weather of fall or winter, but the tasty leaves can be a problem in the heat of summer.

Where To Plant Radishes

If you live inside temperate climate, most likely you have to utilize indoor gardening. If so, then low-tech options must be your way to go. This means planting seeds in the soil and grow them on the windowsill.

If you use soil as your main growing medium, then you need to put it in containers. Any kind of container will do, but plastic pots work wonders. Get the kind with holes at the bottom to improve drainage.

Since radish seeds are really small and because they need light to sprout, you will need to sow them very, very thinly. Don’t put more than two seeds per pot. And remember, the seeds you put in the pot should be germinated first.

If you want to get fancy and you have enough cash in your pocket, consider purchasing an indoor grow light such as the fluorescent tube lamps. This will make for high-quality plants, but they are pretty expensive.

The other option would be to purchase an indoor grow light such as the fluorescent tube lamps. This will make for high-quality plants, but they are pretty expensive.

How To Plant Radishes

Radishes grow best in the cool temperatures of spring and autumn.

Plant the seeds in a general purpose seed mix.

Radishes germinate quickly if you soak the seeds overnight in warm water.

Radishes have a shallow taproot, so they like loose, rich, well-drained soil.

Space the seeds 12" apart. Water them well.

Radishes are a cool-season crop and grow best in spring and autumn. They are especially good for fall planting.

To plant, start with a good seedbed and a light, sandy, fertile soil that's been worked and fertilized. Radishes can be planted in a variety of soil types, and you can plant them in containers, although they will need to be watered more often than if they are planted in soil.

Prepare the bed by adding the planting mix and working it throughout the bed, mixing in fertilizer and lime, as well. Radishes prefer a pH of 6.5 to 7.0.

It is easy enough to plant radishes by broadcasting them in prepared beds (see planting guide above); they'll grow well in that.

If you want to get a bit more controlled about it, you can sow your seeds in furrows 1 to 2 inches wide, and about 2 inches apart. Use your fingers to loosen the soil as you place the seeds in the furrow.

How To Care For Radishes

RADISHES RISE to the occasion. That's because radishes are super easy to grow and are often ready to harvest in as little as 28 days. Start the sow-the-seed process in cool weather, and you'll have baby red radishes for spring salads. Plant them in the late summer, and you'll enjoy a steady supply of crunchy roots during the cold months.

Growing radishes is an ideal project for beginning gardeners, children, and even the most casual of gardeners. These crisp, delicate roots are very nutritious and add an interesting, spicy kick to salads and stir-fries.

Fall is a good time to plant radishes in the Northern part of the country and very early spring in the South. Cool weather stabilizes radish flavor, and root development is faster during cooler months. The goal is a crisp, juicy radish that is uniform in size. If you don't have room or time to let your radishes grow in stages, plant quick-maturing radishes in sowings every two weeks from spring through fall.

Radishes typically take 21-28 days to mature, so keep that in mind when planning your crop. If you are using a seed packet to guide you, plant it at the earliest date possible. Radishes germinate quickly and are relatively hearty, so you can stagger your plantings to keep some of the radishes coming at all times.

Light

Radishes like plenty of light and warmth, two more reasons why they like a greenhouse or sun room. They will not grow at temperatures below 59 degrees, nor will they grow at temperatures above 85 degrees.

They like moist, rich soil with lots of nitrogen. If you are using commercial fertilizer, the best ratios are 8:7:8 or 10:8:7. The pH should fall between 5.6 and 6.8.

Check the soil condition with your finger about a half inch before planting. If it is too cool or dry, add some warm water or rich compost.

Apply your commercial fertilizer, wait about 2 weeks, and then start planting.

Temperature

Soil, Lighting.

Radish seeds are one of the most mature of all crops, and they are easily found for purchase. They are a staple for organic gardening due to their quick germination and fast growth. As these seeds are quite hardy, they are often grown in containers and raised indoors, especially during the colder months.

When you purchase your seeds, make sure you get only white or black coloured radishes. One interesting thing about these favourite gardening crops is their variation in colour. While most of these only come in white and red, there are some, such as the Shogoin black ones, which are rarer but considered to be sweeter.

You can get your radishes to germinate faster by pre-soaking them in room temperature for 24 hours or carefully drying your seeds and placing them in the refrigerator for about a week before sowing. Also, you can get your radishes to germinate even faster by soaking them in skin-tearing salt. You can make this solution by mixing one tablespoon of salt with about four cups of water. You should also make sure that you sow your seeds about an inch deep, and the best time for sowing is the fall when the soil temperature reaches 65 degrees.

Watering

Radishes are very sensitive to being over-watered. The crop does not like wet feet, even when growing in raised beds.

Optimal results: The crop likes compost infused with a reasonable amount of organic fertilizer. Amend the bed with compost. Radishes, like lettuce, are the consummate cool-season crop, and they grow best when soil temperatures run between 60 and 80 degrees F. Organic fertilizers like alfalfa meal are particularly useful for providing slow-release nutrients and moisture retention.

How-to watering: Water radishes using an end-of-season methodology. Do this by using your garden hose to water the soil and not the leaves. You get the best results by using 2-3 gallons of water per bushel of plants. Work the water into the soil. Finally, drench the soil with a continual water application.

Radishes prefer to be moist and do not like being wilted or overdrawn.

Soil

Radishes need rich, well-drained soil if you want them to grow quickly. Add several inches of compost to the soil where you plan to grow radishes. Organic matter is essential to keeping the soil loose, and will aid the radishes in accessing the water and nutrients that they need.

Fertilizing Your Radishes

Radishes are one of the easiest vegetables to grow in the garden. Whether you’re planting from seed or transplanting container-grown plants, radishes grow quickly in most soils. When using fertilizer, work it into the soil when you’re initially preparing to plant. Or fertilize once you’ve planted, if you use seedlings and there’s already a supply of nutrients in the soil.

For seedlings, make sure the seedlings are at least two to three weeks old before you fertilize. If you’re planting the seeds directly into the ground, wait until four weeks after the seedlings emerge.

Radish plants need a small amount of nitrogen and a regular supply of phosphorus, potassium, and calcium. The potassium and phosphorus are necessary for good root growth.

This means a regular application of a fertilizer high in phosphorus and potassium will work best.

As an alternative option, if you’re planting regular radishes, you can work aged chicken manure into the soil before planting. Nitrogen can also be added via fertilizer or manure, and potassium can be supplied by gypsum in the soil. The nitrogen and potassium will help the plants mature faster, but they also help the roots develop and the tops grow.

Propagation

You can begin to harvest radishes after only 30 days, but to get the most enjoyment of your crop you should wait it to mature for about two months. If left to grow you can harvest radishes nearly all-year-round, but you will need to thin the crop or they will grow very large and burst in the ground making it rather difficult to harvest.

There are three primary means for growing radishes, and they tend to have a unique taste to suit particular tastes. Radishes grown from seeds will usually produce a single large bulb, so you should plant them slightly deeper than normal, and a whole lot more.

Sow the seeds as soon as they are harvested, but do not keep them for more than two weeks because they will weaken, and any longer and their roots will start to rot. Seeds normally should be sown in shallow rows in good garden earth, albeit the hole should be deep enough that they are buried slightly more than they are tall.

Seeds should be lightly covered and you can make the surface of the soil smoother by lightly treading it down afterwards, however you should do this very gently. A newborn radish cannot withstand even the slightest injury, which is why it is important to ensure the soil is smooth, and to tread on it carefully.

Pruning For Radish Greens

Radishes are grown for their root, but they can also be eaten from the tip. If you want to plant them for a tasty green, you should consider radish greens if you live in a temperate climate. Although they are still harvested in the spring, you can keep harvesting the greens until the fall. Out of all the different types of radishes, the daikon is the best variety for harvesting greens.

If you’re not planning to eat the greens, you should keep the roots to a diameter of 2.5 inches in size so that the radish will keep developing. If you keep to this size, you can harvest greens for almost six months.

The trick to getting the greens to grow is pruning the flowering stalk once it blooms. If you don’t prune it, the leaves will turn yellow. Most radishes will start flowering when they are two weeks to two months old. You should wait until it has reached that age before you start harvesting your first bunch of green leaves.

As your radish grows, the flowering stalk will brighten up and turn the radish green. When it is fully developed and bright green, you should remove it to get the best and most tender radish greens.

Using Radishes As A Cover Crop

Radishes grow quickly and even in cold weather. They are also very easy to grow.

Radishes are referred to as a “bridge crop” because they are planted between longer growing seasons and harvested before the next crop begins. This is important because radishes compete poorly with longer growing plants. If the space is left vacant, the radishes will interfere with the next growth. Therefore, they make the most sense as a cover crop.

Use radishes as a quick bridge crop or a catch crop to avert insect damage to your long crop such as legumes. Radishes can also be used as a main crop. They make a great addition to your garden planting as a companion for lettuce, cauliflower, broccoli, cabbage and other greens. If you grow your own lettuce for the harvest table, you can plant a quick crop of radishes to help ward off cutworms.

Radishes also make an excellent choice as a companion crop to tomatoes. If frost threatens your tomato patch, plant radishes nearby so the radishes will come up any time before then. They'll be a great early food for pollinators.

When you use radishes as a companion plant in your garden, you will have earlier harvests of lettuce or other greens. Planting radishes and greens together also creates a beneficial rotation leaving less pest problems in your garden.

Radishes as a Sprout or Microgreen Crop

Radishes are a common addition to many home and urban gardens. When grown as a microgreen or sprout, they are not only a great addition to the home garden, but also a great way for beginner gardeners to get started with seeds on their very own windowsill.

The radish is similar to the aspect of other sprouters, where they are generally quick to germinate and grow. This helps to take stress off of the sprouting window as the radishes germinate and grow at the same rate. Due to their quick germination period, radishes, when used as a sprout, can be planted again in just a few days, which means radishes can be used for a fast crop, to add variety, or even to be harvested for use immediately. This is a great way to add a familiar crop, to boost a diet.

Radish greens are also edible, and, much like other sprouts such as alfalfa, are very nutritive. Radish greens are very rich in Vitamins A and C and are very high in calcium. This is a large plus to being able to grow them yourself, as radish greens tend to be much cheaper than many other greens or sprouts that your local grocer carries. The radish plant is also very high in potassium.

Harvesting and Storing Radishes

Fresh radishes are available in supermarkets year-round, but they are in season in the warmer months. You can increase the half-life of radishes (both pickling and non-pickling varieties) by keeping them refrigerated with their greens attached to prevent them from becoming too root-bound. If the radishes are fresh (still slightly firm to the touch) rather than ones that have been stored a while, then they should be good for at least another week in the refrigerator.

As long as you stop trimming the greens and choose ones with smaller roots, the radish leaves will continue to grow, becoming larger and greener as the roots get smaller and more mature. Eventually, both the greens and the roots will reach the maximum size- which is a root similar in size to the greens. At that point the greens will turn yellow and start to wither away, and the radish will begin to develop thicker skin along with smaller and less firm roots.

To continue storing radishes after the greens start to wilt, take the radishes out of the refrigerator and let them sit on your counter. As you’re ready to prepare them, trim off about a third of the greens and then use a vegetable peeler to remove the layers of the root to expose the most mature layers.

Harvesting

When your radishes have reached the size you want, harvest them. The easiest way to pick a vegetable is to just bend the stem and gently pull. I do this from the bottom side so that it doesn’t break the roots.

If you want to prevent them from growing out of hand or becoming woody, you can start the harvesting process early by harvesting the outer leaves. This will encourage the plant to grow more leaves and smaller roots.

Harvest time will vary based on variety – some radishes can grow to a pound. In general, harvest radishes when they have reached about half the size you want them to be.

Storing

You have finally grown and harvested your radishes, and you are now looking for ways to store them. You should not store them in the fridge or freezer. That will cause the radishes to become bitter. You should store them in a cool, dry and dark area. Some gardeners like to keep them in a root cellar, which is ideal. You can also simply keep them underneath your bed or in a cupboard in your home.

The key is not to store them where sunlight can easily get to them as this will cause them to wither. To keep them from drying out, feel free to wrap them in paper and then store them in a paper bag. In this way, the paper will help to keep the humidity levels up, keeping your radishes fresh.

Longer Storage Options For Radishes

If you grow your radishes from seeds and buy the tiny seedlings of radishes, you can grow them in a container or in the ground and enjoy them when you want to. The season for radishes is springtime, so they are plentiful at farmer’s markets and grocery stores at that time of the year.

If you grow your radishes when the weather gets warm, you will have an easy time storing radishes for as long as you want. Just like with other vegetables, the more specific the temperature is, the more likely the radishes will last you a longer time. Try to have your radishes at a temperature around 40 degrees F or lower.

When storing radishes in the refrigerator, you can just dump them in a Ziploc bag and seal it. You can also put them outside the refrigerator in a plastic bag and place them in the coldest part of the refrigerator. Be careful when handling radishes after storing them, though: they are easily bruised and picking out a single radish from a pile in the fridge can damage others.

Troubleshooting

Radishes don't taste sharp even after they are the right size!

"Younger radishes have a more pronounced taste than those that are older. You might need to try some to find out which one works for you. If you're getting the smaller ones, use two at a time for flavor or try combining them with a tasty herb salsa."

I don't have room for planting them indoors!

"There are several different ways to grow radishes. They can be grown in the garden, in containers, in a planter — you name it. It's important that the radishes have at least an inch of space between them. They will grow the most if you give them a few inches of the space to grow. If space is a concern, a rack of the vegetable can be placed over your garden bed and will give them enough room to grow."

They are taking too long to grow!

"When growing them indoors, the time from planting to harvesting may take longer. Take your time and enjoy watching them grow."

Growing Problems

Radishes develop rapidly, so be ready to harvest them a day or two after their tops have appeared from the soil. If you notice that your crop is falling over or leaning to one side, it is time to pick them.

As with raising all edible plants, growing radishes can be a challenge. Though many gardeners have problems growing these common salad fixings, the problems are usually easy to solve. Here are a few of the mistakes you could make while trying to grow radishes and a few ways to avoid them.

Don’t expect your radishes to be ready a day after you plant them: It takes about four to six weeks for a radish crop to grow to maturity. You should plant radish seeds a few weeks before your last spring frost date, or you can plant them in fall for a winter crop. If you plant them too early, you run the risk that the ground will warm too much and the seed will not germinate. If you plant them too late, you risk planting them right before a frost. A quick test to see if your radishes will germinate is to soak the seeds in a bowl of cold water. If they sink, they are dead and won’t germinate.

Pests

And Diseases Radishes prefer full sun. The soil should be loose and well drained. Thoroughly mix aged compost, leaf mold, or manure, with the soil prior to planting if possible. These provide the essential nutrients that radishes love.

Radishes are best grown in narrow rows, about 18-24 inches apart. This gives the best results. Once the leaves are developed and fairly large, you should thin out every other plant. This promotes a strong, healthy root and makes harvesting easier. If you choose to grow radishes in containers or window boxes, you will need to thin them to about one per container.

Diseases

Radishes are not affected by many diseases, which is a blessing for the gardener who has so little growing time. One important disease to watch out is verticillium wilt. This disease causes gradual wilting of the plant. If you see yellow patches in the leaves of the plant before the first bulb has formed, this is an indication of verticillium wilt.

Other diseases to watch out for are:

  • Alternaria blight: It is a common fungal disease that affects young leaves and causes small brown or black spots on them.
  • Rhizoctonia: This disease causes the leaves of the plant to wilt and drop early. However, if you do not remove infected leaves early enough, they can cause infection that is spread to the rest of the plant.

Frequently Asked Questions

Here are the most frequently asked questions that I get about growing radishes.

Q. Will the leaves on a radish plant affect the taste of the radishes?

A. No, the leaves on a radish plant (or any plant for that matter) will not affect the taste of the radishes.

Q. Can I eat radish leaves?

A. Yes, you can eat radish leaves in different ways, like you can with carrot tops. You can enjoy raw radish leaves as a salad, or cook them with a little oil and a sweetener and use them as a side dish.

Q. Do radishes need lots of work to grow?

A. Some types of radishes require more work because they are not very resistant to disease and insects, so they have to be carefully managed in order to prevent infestations. I recommend using the Asian variety in order to avoid this problem.

Q. Can I use the seeds radishes to grow or are they simply for decoration?

A. You can definitely use radish seeds to grow radishes. However, you will get different tasting radishes if you plant to seed versus if you buy plants for harvesting.

Q. Should I remove the bottom leaves of a radish plant?

A. No, you should never remove the bottom leaves of your radish plants because they are extremely important for the plant's survival.

Q: Are horseradishes also radishes?

A: Horseradish is a pungent root grown for its hot flavor. It's a member of the mustard family, so it's not related to radishes, although all have about the same growing requirements.

Radishes (Raphanus sativus) are a cool-weather crop grown from seed that come in a wide range of both root shapes and colors. They do well spring through fall in all zones.

Radishes are usually long, red root, but they can be white, yellow, purple, black, and even golf ball-sized.

Growing radishes isn't hard, but making sure they form their leaves and roots properly is important. You've probably noticed that radishes in the grocery store are small, but at the farmers market they may be in the golf ball range, or even larger.

The only key difference between the different radishes is the growing conditions, and it's relatively easy to replicate those conditions in any home garden.

Q: Is wasabi a type of radish?

The wasabi plant is a plant in the Brassicaceae family. Its leaves are used to make the wasabi consumed as a spice. Its leaves are also known as Japanese horseradish.

The wasabi plant is part of the cabbage family, which is made up of Brassica species.

The wasabi plant has four major subspecies the Japanese wasabi or Eutrema japonicum, the Horseradish tree or Moringa oleifera, the Water wasabi or Coptis teeta and the wasabi plant or Eutrema japonicum.

Q: Are radishes good for weight loss?

A: Radishes are a wonderful addition to your diet. They help with weight loss in a number of ways. The first way experts think they help with weight loss is by their high fiber content. Why is fiber important? It has been found to increase feelings of fullness. A full feeling can lead to fewer calories consumed throughout the day. A second reason radishes are thought to aid in weight loss is because of their low calorie content. With only about 20 calories per serving, they can add another low-calorie side dish to your meals.

A third way radishes can aid in weight loss is because of their high water content. Over-eating can cause to many calories to be consumed. Drinking enough water can help individuals feel full and can help reduce over-eating.