All About Growing Radishes
Radishes are grown in just about every vegetable garden. They are quick to grow and the big seeds are ideal for gardening with kids.
When we hear radish, many of us think of small, round, red and tangy. By far, the most popular radishes eaten and grown fit this description. Although there are longer varieties and different color radishes, small round radishes are such quick and easy growers, they virtually define what a radish should be.
Even this humble globe-shaped radish offers a good amount of variety. They can be round or oblong, hot or mild, red, pink, purple, white or bi-colored.
The Asian radish varieties are often referred to as “winter radishes”, because they mature late in the season and can be stored over winter. Daikon is a Japanese word meaning “great root” and some of these radishes can indeed become great in size, although not all Asian radishes are long. The black radishes tend to be the hottest.
Don’t forget that the tops or greens of radishes are also edible, as are the pods. There are even varieties, like 'Rat's Tail' radish, that are grown specifically for their pungent pods, which grow all summer long.
Radishes are annual plants, and quick ones at that.
So they have no USDA Hardiness Zone rating.
Radish size varies widely. Small globe-shaped radishes are best when about 1 inch in diameter. The longer Daikon types can reach 8 - 14 inches in length and 2 - 4 inches in diameter.
Full sun to partial shade. The common, small radishes need to grow quickly, in cool weather, so they need plenty of sun.
Days to Harvest
This depends on the type of radish you are growing. Some of the smaller radishes mature in as little as 25 days. The larger winter radishes can keep you waiting up to 60 days.
Spring Radishes - The fast maturing, round radishes are ready for harvest in 3-4 weeks. You’ll usually see the top portion of the radish poking up through the soil. When it appears to be almost an inch across, it is ready to pick. Radishes can be harvested by pulling or by gently loosening the surrounding soil. Don’t let mature radishes sit in the ground or they will get either woody or spongy.
Winter Radishes - The long, Asian radish varieties take longer to mature, sometimes up to 3 months. They should be harvested before the ground freezes and can be stored for several months.
The thinned plants of all varieties can be used as salad greens or on sandwiches or floating on soups.
Remove the green tops and store the bulbs and tops separately. Leaving the leaves on will draw moisture and nutrients from the radish bulb. The globe-shaped radishes can be stored in the refrigerator, in plastic, for about a week. Winter radishes will last about 2 weeks in the fridge or several months in cold storage.
Radish Growing Tips
Radishes are a cool season vegetable that can mature very quickly. The small, round varieties will get woody if grown in hot temperatures.
Planting Radishes: Radishes, like most vegetables grown for their roots, are direct seeded in the garden. They can be started very early in the spring, as soon as the ground is relatively dry, and again towards the end of summer, for a fall garden, and even in late fall, with the protection of a cold frame. Since radishes grow quickly, they can be squeezed in between other plants, in the vegetable garden. The radishes will be harvested before the other vegetables need the extra room. Plus, radishes are good for loosening and cultivating soil for slower sprouting vegetables, like carrots.
Sow seeds 1/4 to 1/2 inch deep. You’ll want at least 2 inches between plants, but seedlings can be thinned and eaten when they are an inch or two tall.
Caring for Radish Plants
Since radishes are so quick growing, they don’t require fertilizing, although a rich well-draining soil is needed to begin with. Check size frequently, to harvest before they begin to decline. You can feel the size of the tops, just below the soil line, or go ahead and pull a few.
To have a continual harvest, succession sow a new crop every 10 - 14 days, until it gets too warm. Most radishes bolt to seed in hot weather. The edible podded radishes are a great substitute during summer, since you want them to go to seed.
Growing Radishes in Containers
The fast growing, spring radishes grow quite well in pots and growing them this way is a good option if you are plagued by root maggots. They will need at least 4 inches of soil depth and lots of water.
Suggested Radish Varieties to Grow
Early Spring Varieties
- 'Cherry Belle' - Round, Red (22 days)
- 'Early Scarlet Globe' - Round, Red (22 days)
- 'Easter Egg' - Oval, Mixed Colors ( (25 days)
More Heat Tolerant
- 'French Breakfast' - Oblong, Red / White Base (23 days)
- 'Icicle' - Long & Slender, White (25 days)
- 'Rat Tailed' - Grown for its edible pods, not its root. (45 - 50 days)
- 'China Rose' - Red Skin / White Flesh ((52 days)
- 'Round Black Spanish' - Black Skin / White Flesh ((55 days)
- Daikon - Long, White and surprisingly mild (60 days)
Pests and Problems
- Cabbage Root Maggots are more of a problem in northern gardens, where they will tunnel into radishes.
- Cutworms can also feed on radishes.
- Flea beetles will make Swiss cheese of radish leaves, but don’t injure the bulb.
Monitor to catch these insects before they destroy the whole crop. You can avoid them almost entirely by growing your radishes under row covers.
Radishes decline in quality when the temperature warms. They can get tough and woody or spongy with hollow centers. Once a radish bolts, or goes to seed, the bulb stops forming.