Ever wanted to know how to grow radishes? Radishes are one of the most popular ingredients in most salads and veggie trays – and for good reason. They’re extremely nutritious and quite easy to grow. Some of the fastest-growing radish varieties can mature in as little as three weeks.
Because they’re quick growers, they make a good crop to plant to mark areas where you’ve planted slower-germinating vegetables like carrots or parsnips.
Today, we’ll talk all about Raphanus raphanistrum subsp. sativus, the radish plant. Everything you ever wanted or needed to know about these delicious little roots is right here!
Radishes: Quick Care Guide
|Common Name||Radish, daikon, and an extremely wide variety of individual cultivar names|
|Scientific Name||Raphanus raphanistrum subsp. sativus|
|Germination Time||5-14 days depending on cultivar|
|Days to Harvest||25-100 days depending on cultivar|
|Water||Even watering, about 1” per week|
|Temperature||55-65 degrees Fahrenheit optimal, can take 40-70 degrees depending on cultivar|
|Humidity||Moderate to high|
|Soil||Well-draining, prefers sandy loam, 65-70 pH|
|Fertilizer||None. No, really, none is needed.|
|Pests||Aphids, cabbage loopers, flea beetles, some nematodes|
|Diseases||Downy mildew, bacterial (septoria) leaf spot, white rust, club root|
Recommended Radish Varieties
There’s plenty of varieties of radish out there. Really, the most difficult decision is in terms of what color of radish you’d like to grow, as there’s a surprisingly wide number. Size may also be a factor, especially if you consider growing daikon varieties – they can become incredibly huge!
Here’s a list of some of the most popular varieties today and where you can find them.
These are what most Americans think of when they consider radishes. Typically either round or oval in shape, these are the small radishes used most commonly for salads and snacking.
|Variety||Growing Time||Description||Where To Buy|
|Cherry Belle||25 days||Round and red with a crisp white core. Tolerant of poor soil, grows in dry, hot weather.||Buy Seeds|
|Burpee White||25 days||Pure white radish, best eaten at 1″ across. Quick and easy to grow in cool weather.||Buy Seeds|
|Pink Beauty||26 days||Uniform, round roots. Crisp texture and taste. Pastel pink coloration.||Buy Seeds|
|German Giant||29 days||Large, 1.5″ across round radishes. Crimson skin, mild white flesh. Grows quickly!||Buy Seeds|
|Bacchus||30 days||A round and vibrantly purple radish. Can get quite spicy in hot weather.||Buy Seeds|
|French Breakfast||30 days||Purplish-red at the top, gradually lightening to white at the root end. Best grown spring through summer.||Buy Seeds|
|Helios||32 days||Bright yellow radish with great flavor. Quick grower, looks good in salads.||Buy Seeds|
|White Icicle||32 days||Snowy white, this heirloom radish can grow to be 5-6″ in length and about 1″ in diameter.||Buy Seeds|
|Black Spanish||55 days||Snow-white interior, jet-black skin. Extremely old heirloom variety.||Buy Seeds|
These Asian radishes can grow to extremely large sizes. There have been reports of some daikon radishes that have reached a yard in length! Commonly used to make kimchi, made into a pickled slaw of daikon and carrot, or cooked with traditional Asian foods, this somewhat sweet radish is popular. They can be eaten raw as well.
|Variety||Growing Time||Description||Where To Buy|
|Mini Mak||50 days||Miniature daikon, grows to 4″ long x 1.5″ wide. Good alternative when a full-sized daikon is too big.||Buy Seeds|
|Miyashige||50 days||Fall harvest daikon variety. Green and white in coloration. Can reach 18″ long and 3″ wide.||Buy Seeds|
|Green Luobo||60 days||Sweet, crispy green flesh. Grows up to 10″ long, but can be harvested at 6″ lengths.||Buy Seeds|
|Daikon Long||60 days||Averages about 14″ in length. White with a green neck. Good standard variety.||Buy Seeds|
|Minowase||60 days||Popular Japanese hybrid radish. Can reach 16″ long and weigh close to 2lbs.||Buy Seeds|
Wild colors, extreme size – these are some of the crazier and more unique radish varieties available right now. Great to grow if you want something truly unique in your garden!
|Variety||Growing Time||Description||Where To Buy|
|Dragon||40 days||Fiery red skin, white interior. Best harvested at 4-5″ long. Great slicers.||Buy Seeds|
|Bravo||49 days||Pale purple to white with purple streaks, 5-6″ long by 2.5-3″ wide. Sweet flavor.||Buy Seeds|
|Rat-Tail||50 days||This radish is grown for its edible seed pods, not its root! Seed pods grow to 6″ in length.||Buy Seeds|
|Watermelon||50-60 days||With roots growing 2-4″ in length, this white-skinned radish has a vivid purple-pink interior.||Buy Seeds|
|Sakurajima Giant||100 days||Grown in Japan as the “largest radish in the world”, commonly reaches 15 pounds weight in that country. One specimen was nearly 100 pounds!||Buy Seeds|
|Schifferstadt Long Black||Not stated, estimated 70 days||1700’s era Pennsylvania Dutch variety. Can reach 16″ in length and weigh several pounds. Black skin, white flesh.||Buy Seeds|
Of all the vegetable types, radishes are some of the easiest to grow. In fact, they’re a great first crop for children because of how quickly some varieties are ready to eat! It’s about as close to instant gratification as a plant can achieve. Here’s how to get started.
When To Plant Radishes
Like many other plants, there are different radishes which flourish in different seasons. However, most radishes fall into two varieties: spring/summer, or fall/winter.
Spring/summer radishes can be planted as soon as the ground is workable in the spring, and grown sometimes well into the summer. Most heat-resistant varieties of radish fall into this category. Early varieties are less heat-tolerant, but you can still get a reasonable crop of radishes from those before switching to a more heat-tolerant type.
Fall/winter radishes include many of the larger radish varieties as well as some of the sweeter radish types. These can take a while to mature, but tend to be quite cold-tolerant. While a hard freeze will be a problem, occasional light frosts do not seem to bother most of these plants.
To have a continuous harvest, begin planting at the earliest point of the spring, and sow more seed weekly to keep plants in all stages of development. When you near the hottest part of the year, stop sowing until the weather begins to cool again, and then switch to fall/winter varieties. If you have hard freeze conditions, protect your plants with a cold frame.
Where To Plant Radishes
You can plant radishes almost anywhere. However, as with any root crop, you’ll need to be sure that the soil is loosened up to enable easy root growth.
For fast-growing small radishes, loosen the soil at least six inches deep. For larger radishes like daikons, or winter-growing varieties, loosen the soil to two feet.
You can grow the spring-summer varieties indoors under grow lights easily in the dead of winter, as long as the ambient temperature is around 40 degrees or higher and the soil is warm. Container growing is just fine for these varieties.
Larger-rooted varieties will need a lot more space to grow. It’s advisable to grow these directly in the soil or in a raised bed environment. A 24″ tall raised bed is perfect for most varieties of daikon, for instance.
These crops make great companion plants for squash varieties or cucumbers, as they deter cucumber beetles. Similarly, if you’re growing spinach, they will distract leafminers from your spinach plants. They can also be planted with beans (both bush and pole varieties), melons, lettuce, beets, tomatoes, carrots, or peas. They enjoy the company of nasturtium plants as well.
Do not plant radishes with potatoes or hyssop plants, as they do not get along with these plants and may actually suffer poor growth near them.
How To Plant Radishes
Once you have prepared the soil for your radish variety (loosened to 6″ for smaller radishes, 24″ for larger types), plant your seeds. Generally, radishes like to be planted a half-inch deep and about an inch apart. After you have planted your seeds, pat the soil firm overtop and gently water.
Once your seeds germinate, thin them to 2 inches apart (or 3-6″ apart for larger varieties, depending on the type). Begin sowing new seeds weekly to maintain a steady harvest of radishes.
Lay down a layer of mulch around your plants to prevent weed growth. Water regularly for best growth and flavor.
How To Care For Radishes
Honestly, radishes are pretty easy to maintain, but let’s go over the basics for the best possible conditions for your radish crops!
Radishes need full sun conditions. Too much shade, and they’ll put all of their energy into producing leaves instead of the roots. Be sure your radishes get at least eight hours of sun.
Root crops like radishes experience their best growth at 55-65 degrees Fahrenheit in humid conditions. Depending on variety, they can handle colder or warmer conditions as well. Generally speaking, if the weather is between 40-70 degrees, you should be just fine for most radishes.
Winter varieties can easily handle weather down into the 40’s, as long as the soil temperature remains consistently warmer than the air temperature. Some can handle light frosts, but not repeatedly.
If the temperature is higher than 90 degrees, most radish seeds will not germinate. Radish plants will struggle in 80 degree conditions, and may bolt to seed at that point.
Consistent, even moisture is essential for radishes. They don’t like muddy conditions, but they do want lots of moisture regularly. Be sure your soil remains moist, yet not soggy.
The peak demand for water is going to be while your plants are developing and building large roots. Once they’ve started to develop that large root, just keep the moisture regular and they’ll handle the rest.
A well-draining, light sandy loam with a pH between 6.5 and 7.0 is perfect for your radishes. However, most radishes will take a wide variety of soil types, just as long as they’re well-draining and don’t turn into mud puddles.
Fertilizing Your Radishes
Radishes really don’t need much fertilizer, if any. To be quite honest, it’s far too easy to overfertilize your radishes.
If you wish to use fertilizer at all, use a low-nitrogen option. Often gardeners offer as much nitrogen as they can to their plants, but nitrogen spurs leaf development instead of root development, and we want the radish roots to be plump and tasty! Something which is higher in potassium and phosphorous will help encourage the root growth rather than the greens.
Radishes can only be propagated by seed. As they are a fast-growing root crop from germination to full development, you can harvest most of your radishes for the roots, and leave a few to develop seed pods.
To harvest radish seed, allow the pods to dry on the plant. Once they start to turn brown, pull the entire plant up and knock off any dirt clinging to the roots. Place it in a paper bag upside-down. Allow the pods to finish drying out completely. When they have totally dried, the pods will pop open and the seeds will drop into the bag.
Pruning For Radish Greens
Most radishes have developed spiky hair-like protrusions on their foliage to protect the plant. However, if you have a “hairless” variety of radish leaf, you can harvest and eat the radish greens. White Icicle is a good example of a hairless variety.
There are some varieties of radish that are actually grown more for their greens than for the root, in fact! These are referred to as “radish leaf” types, and are commonly found with other Asian seed varieties.
If harvesting radish greens, pick them when they are young and tender and the roots are just forming. You can snip a couple leaves off of a given plant at ground level and allow the rest to remain to keep the root alive. Alternately, simply harvest the whole plant to eat all of the greens and the young, small root.
Using Radishes As A Cover Crop
In recent years, the use of radishes as a cover crop has become much more popular, especially in areas which get hard freezes. Planting long varieties like daikon in the fall gives the extended roots plenty of time to bore deep into the soil. When freezing weather occurs, the radishes die off. However, their roots retain nitrogen, and release it slowly as they decompose. By spring, the soil is not only loosened for planting, but it is nutrient-dense.
While crop rotation should be practiced if using this method, so as to not develop radish pests in a given area, this method is proving to be quite useful to many large-scale farmers.
Whether this method will work or not in a home garden is less known, but it should work just as readily on a small scale as on a large scale. In addition, as the radish roots decompose quickly, it adds lots of organic matter to the soil fast. It’s slowly gaining popularity among gardeners who practice no-till methods of growing.
Radishes as a Sprout or Microgreen Crop
You can easily grow radishes as sprouts or microgreens for salads and sandwiches!
Daikon, China Rose, White Icicle, and some other radishes make excellent sprouts. You can make a sprout jar out of a large mason jar, in fact. Place a tablespoon or two of radish seeds into the jar and soak them overnight, then thoroughly drain all of the water out. You can use the ring from the jar with a piece of fine mesh or cloth over it to keep the seeds inside while you drain. Then, remove the top and place in a dark place.
Rinse the seeds with fresh water every 8-12 hours, being sure to drain them off completely each time, and be sure to keep them in a dark location like a cupboard. Within 2-5 days, you should have a crop of radish sprouts ready to eat.
Remove them from the jar and place them into a large bowl, and fill with water. Swish them around to remove any hulls, which should float away from the sprouts easily. Then drain them completely once more and store them in the refrigerator. Your sprouts should keep for up to a week, but you’ll probably eat them before that time is up!
As for microgreens, I recommend watching this video, which will teach you the process of how to get a batch of radish (or other) microgreens started!
Harvesting and Storing Radishes
Harvesting big radishes can be a little tricky. Also, most people don’t think about storing radishes for long — they’re so good when they’re fresh! But with a few tips, you can harvest and store your produce like a pro.
Radishes are best harvested sooner rather than later. Harvested too late, they may begin to crack or lose their flavor.
For smaller radishes, keep a book with estimated harvest dates, based on the estimated time of growth. About a week before the estimated full growth, pick a good-looking radish and pull it out. Check the size of the radish. If it’s full sized, you can begin to harvest then. If it still has a bit of time to go, wait for another week to pass and then check another radish.
The process is similar for larger radishes, but wait until the actual estimated date to begin checking their status. These can be harvested at any point up until the first frost date in the fall. (You can extend the harvest period with the use of a cold frame.)
Daikon radishes or other large varieties can be difficult to harvest, as the greens may break off in your hand. Use a digging fork to loosen the soil around your large radishes gently, and then grasp the greens and top of the radish to pull it from the soil. Be careful not to bend the longer radishes as you pull them out, as you may break them in half. You should pull them straight up from the soil for best results.
If you are harvesting edible-pod radishes, watch for the blossoms to appear, then begin checking your plants every 2-3 days. Edible pods will look similar to green beans, and will be ripe and ready to pick when they’re about the thickness of a pencil. The lowest pods will be ripe first.
Harvest the pods by grasping the small stem at the end of the pod and bending it sideways. It should snap off from where the stem attaches to the branch.
If you are going to use your radishes within a few days’ time, consider water-storage. Place your radishes in a shallow bowl with 1-2″ of water, greens still attached, and place it in the refrigerator. The greens and roots will last for 5-7 days easily this way.
You can jar-store your smaller radishes. Remove the greens entirely, wash the radishes off thoroughly, then place them in a jar and cover them with cool water. The water helps the root stay hydrated and preserves them for longer. You can store the jar in the refrigerator for up to a couple weeks.
Alternately, remove the greens, then place the unwashed radishes in a ziplock bag with a moistened paper towel in the bottom to keep their humidity up. Place them in a dark crisper drawer in the fridge. They can last up to a month this way, as long as they have enough moisture. Check them at least once a week to be sure no mold or rot is forming, and dispose of any which are doubtful.
Winter varieties can be stored in a cold root cellar or basement at between 34-42 degrees Fahrenheit, and with high humidity of 90-95%. To do this, prepare a box with layers of moist sand separating the unwashed roots. Be sure that none of the roots are directly touching one another to avoid the spread of any rot, should it occur.
Check your radishes every week to make sure none are developing mold or rot. If any have developed rots or mold, remove them and get rid of them. Well-stored winter radishes can last for up to three months if maintained in this environment.
Winter varieties can also be stored directly in the soil they grew in! A thick layer of straw or hay, about 4-5 inches deep, will help insulate your plants. Alternately, use a cold frame to keep your plants warm.
Edible radish pods do not store as well as root radishes. Use them quickly after harvesting. You can store them in a ziplock bag in the refrigerator for up to one week.
Radish greens do not store well at all. It is best to use them the day of harvesting them so that they’re fresh.
Longer Storage Options For Radishes
You can pickle most types of radish to extend their preservation time. There are a number of recipes out there for a radish-pickling brine, but usually it’s a mix of vinegar, salt, sugar, and herbs. Occasionally some wine is added for flavor. Depending on the brine used, these can store for anywhere from a month up to six months in the refrigerator, although most varieties are best used within 1-3 months after pickling.
Radishes can be dehydrated or freeze-dried. Either method works quite well to produce crispy little radish chips. However, be forewarned that, like other cruciferous vegetables, freeze-dried or dehydrated radishes can still emit a gas that can compromise a vacuum seal. It’s best to store these in a glass mason jar with some dessicant packets, in a dark cupboard or other dark storage space.
You can also use those dehydrated or freeze-dried radishes to make a radish powder that can be added to soups, stews, or other dishes to give an added burst of radish flavor. This can also be used to make a radish sauce that’s like a milder horseradish flavor.
Radishes do not normally freeze well, so I do not advise freezing most varieties. The one exception is daikon. To freeze daikon radishes, scrub them off thoroughly in water to remove any dirt. Cut them into small pieces or grate them. Blanch the radishes in boiling water for 2-3 minutes, then put them into an ice bath to stop the cooking process. Drain well, then place into a plastic bag and freeze.
Freezing will change the daikon texture slightly, but the blanching process will stop them from becoming rubbery like other radish varieties might. This blanching does not work as well on smaller radish varieties.
While radishes are easy to grow, there can always be problems. Let’s go over those now.
In hot weather, radishes are prone to bolting, sending up a seed stalk as quickly as possible. Once that seed stalk starts to form, your radish root is no longer viable. It loses its flavor rapidly and starts diminishing in size, as the plant will be using all the nutrition in its root to develop seeds.
To prevent bolting, harvest as soon as the radish has reached a reasonable size. This is true of virtually every radish type that’s out there – an early harvest is best! Also, don’t plant seeds when the weather is consistently over 75 degrees. At that point, your radishes are simply going to have a hard time developing good roots.
If your radishes are cracking, that is usually a sign of uneven watering. Be sure your radishes have regular, even watering.
Woody radish roots can be caused by a combination of warmer weather and underwatering. They really prefer the cooler temperatures and regular watering that promotes good root growth. If you ensure they have optimal conditions, you’ll have a great crop.
Finally, if all you seem to be growing is radish greens and no root is developing, you may have too much nitrogen in your soil. Radishes do surprisingly well in poorer soil quality. Adding a little phosphorus or potassium may help boost root development in your radish bed, too. You also may not be thinning them out enough – radishes need room to grow!
Some forms of nematode, such as root-knot nematode, will cause problems with the radish roots. You can combat this in one of two ways. Adding beneficial nematodes to the soil is known to reduce the population of root-knot nematode, as the beneficial forms will seek out and kill the harmful ones. Alternately, you can use an azadirachtin drench on the soil made from a product like Azatrol EC. However, this will kill all nematodes, whether beneficial or pestilent.
Aphids are a very common pest on radish greens, and can cause the greens to wilt rapidly. To prevent aphid infestation or to eliminate them if they are already there, use a thorough coating of neem oil across all surfaces of the plant’s leaves. A pyrethrin spray such as Safer Brand Yard & Garden Spray can also be used.
Cabbage loopers will not only chew holes through radish leaves, but they may gnaw on the emerging tops of radishes and open them up to disease. Bacillus thurigiensis, or BT, is effective on all forms of caterpillars. I recommend Monterey BT spray, as it’s quick and effective.
Flea beetles can also wreak havoc on the greens and eat into the roots of the radishes. Azatrol EC is useful against these as well. To prevent flea beetle infestation, you can use a dusting of kaolin clay (I use Surround WP) over all surfaces of the radish to deter them.
Downy mildew can become a problem on radish greens. While this doesn’t necessarily hurt the roots themselves, if it starts too early, the roots may never have the chance to grow to a reasonable size. You can treat downy mildew with neem oil as a fungicidal agent. It may take a few treatments, but it will eliminate the mildew on the leaves.
Bacterial leaf spot can also form on radish greens. This, too, can be treated with neem oil, but it may take a bit longer for it to be effective.
White rust can develop on radishes, wild mustards, and other plants such as spinach. This can cause small, light green spots to form on the leaves. Gradually, the spots will turn white and form a blister-like pustule. This fungus-like microorganism can be treated using Bonide Copper Fungicide.
Finally, club root is another fungal infection which plagues many types of brassicas. This fungus cannot be treated by fungicidal sprays or drenches. It can be incredibly hard to eliminate, and often plants that are impacted must be destroyed, and not replanted in that area. You may be able to sterilize your soil by placing a clear plastic sheet over it for a few months during the heat of the summer, but this will also kill off any beneficial nematodes and other beneficial organisms in the soil.
Frequently Asked Questions
Q: Are horseradishes also radishes?
A: While horseradishes and radishes are both brassica plants, they are two different species. They grow similarly, and both have a spicy flavor, but they aren’t the same!
Q: Is wasabi a type of radish?
A: Also related to radishes, wasabi is another brassica family plant. It is not the same as either horseradish or radish, but it’s related to both and can have similar problems. Wasabi also prefers much wetter growing conditions than either horseradishes or radishes.
Q: Are radishes good for weight loss?
A: While a nutritionist can answer that question far more thoroughly than I can, it should come as no surprise that radishes contain quite a lot of fiber. Fiber can help you feel as though you’re full, which can aid in weight loss. They’re also low-calorie foods, and make a great light snack!
Are you ready to start your next batch of radishes? I know I am! What’s your favorite kind of radish? How do you enjoy eating them the most? Tell us all in the comments!
Article updated on 1/22/2018.
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