Photo by Rachael Brugger
Radishes are among the fastest-maturing garden crops. They’re fairly simple to grow, and with regular spring and fall sowings, gardeners can fill their salad bowls with the crisp crunch of radish roots for months on end. But the trick to prolonging the harvest of this nutritious vegetable lies not just in extending the planting season, but also in extending the storage time of harvested roots. Keep these tips in mind during radish harvesting so they’ll keep until you’re ready to eat them.
1. Harvest from dry soil.
Dig or pull radishes after a few days of dry weather. Excessive moisture can cause the harvested radish roots to rot. Plus, harvesting after the fine root hairs dry out a bit allows the plant to shift into a sort of dormancy, extending the shelf life by a few extra days.
2. Hydro-cool for short-term storage.
If you plan to eat the radishes within a week, simply fill a shallow bowl or baking pan with 1 to 2 inches of water, and set the harvested radish plants in it. (It should look like they are growing out of the water rather than out of soil.) At room temperature, the greens and roots will stay fresh like this for several days. If the bowl is placed in the fridge, you can expect five to eight days before wilting occurs.
3. Chop off the greens.
Once harvested, cut off the radishes’ leafy green tops just above where the stems meet the root. Keep the roots unwashed and in the fridge until you’re ready to use them. They'll last one to two weeks in a sealed plastic bag. Radish greens are excellent braised or sautéed in olive oil with a touch of roasted garlic, salt and pepper.
4. Store radish roots in water.
As an alternative to hydro-cooling, wash and trim the roots, removing both the greens and the small tap root extending out the bottom. Drain excess water and stuff radishes in a large canning jar with layers of trimmed radishes. Fill the rest of the jar with water, put on the lid, and keep it in the fridge. The roots will stay crisp for five to eight days.
5. Zip and seal.
For longer storage, put unwashed radishes with their greens removed in a plastic zip-top baggie with a slightly damp, folded paper towel at the bottom. Put the bag in a cool, moist, dark place, like the crisper drawer of the fridge. They'll last several weeks stored in this manner.
6. Go the cellar route.
If fridge space is limited at your farm, store harvested radishes in a root cellar or basement between 34 and 42 degrees F, with high humidity (90 to 95 percent). Fill cardboard or wooden boxes or crates with slightly damp sand and spread the unwashed roots between layers of sand, being sure none of the roots touch to avoid the spread of rot, should any occur. Check the roots every week or two for signs of mold or rot. Remove roots showing signs of rot.
With proper sand storage, radishes should last up to three months. This technique works best for fall and winter radishes, as well as daikon radishes, which have thicker skin and are less likely to desiccate. Winter varieties include Miyashige, Misato Rose, China Rose and Black Spanish Round.
7. Store in the dirt.
It's also possible to store fall-grown radishes in the ground. Plant a late-season sowing of salad radishes 30 days before your first expected frost. When the weather turns cold, the roots will stop growing, and you'll need to protect them with a thick layer of straw or hay—4 to 5 inches should suffice. As long as the ground remains unfrozen, the radishes can be harvested a few at a time. Another option is to cover the plants with a double layer of floating row cover or erect a mini-greenhouse over them.
8. Store in a cold frame.
Another in-ground storage option for fall-sown radishes is a cold frame. In fact, with a cold frame in place, gardeners in many parts of the country can enjoy freshly harvested radish through most of the fall, winter and spring. Sow a handful of new seeds every few weeks and rejuvenate the cold frame's soil with a few inches of compost or well-aged manure twice per season. To make the best use of winter's elusive sunlight, be sure your cold frame faces south to maximize the amount of light reaching your plants. Having a sloped frame also aids in light and heat absorption—a 45-degree, south-facing slope is ideal.
About the Author: Horticulturist Jessica Walliser is the author of Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control (Timber Press, 2014) and three other gardening books. She is the gardening columnist for the Pittsburgh Tribune-Review and co-hosts "The Organic Gardeners" on KDKA Radio in Pittsburgh.