Growing radishes in home gardens (2024)

• Have your soil tested.
• Any well-drained, slightly acidic to neutral soil with pH 6 to 7 will do for radishes, as long as the soil is not compacted.
• Although daikon can penetrate heavy soils to depths more than one foot, the roots will not be as smooth, uniform and tender as those grown in lighter, prepared soils. If your soil is stony or very heavy, choose shorter daikon varieties.
• You can improve your soil by adding well-rotted manure or compost in spring or fall.
• Do not use fresh manure as it may contain harmful bacteria and increase weed problems. The readily available nitrogen can stimulate branching of the roots.
• Do not use any fertilizer containing a weed killer ("Weed and Feed"), as it may kill your vegetable plants.

1. Prepare the radish bed by loosening soil at least six inches deep, a foot or more for long types. For daikon, create raised beds to ensure loosening of the soil and to make harvest easier.

   

2. Plant radish seeds from early April through early May for a spring crop, and again August 1 through September 1 for a fall crop.
3. Allow about one inch between seeds in the row.
4. Plant the seed of smaller varieties shallowly, one-fourth to one-half inch deep. Plant larger varieties deeper, up to one inch deep. Seedlings will emerge within ten days.
5. Heavy rains or excessive irrigation can cause soil crusting, which may weaken seedling emergence. If the soil surface has crusted, lightly sprinkling it to moisten and soften the crust may help.
6. Thin radishes to about two inches between plants as soon as they reach a small, edible size. For larger varieties, such as daikons, allow four to six inches between plants. Pull any weeds in the row when thinning occurs.

Like other seedlings in the cabbage family, radishes have a distinct appearance: two fleshy cotyledons shaped like capital Bs, followed by true leaves that may be somewhat hairy and toothed.

• Radish taproots can be large, but the horizontal roots do not extend far into the soil. Make sure they receive enough rainfall or deep watering.
• Drought stress can cause the roots to develop poor flavor and a tough texture.
• If the planting does not get one inch of rain each week, soak the soil thoroughly at least once a week.
• If your soil is sandy, it is important to water more often than once a week.
• An inch of water will wet a sandy soil to a depth of ten inches, a heavy clay soil to six inches.
• Use a trowel to see how far down the soil is wet. If it is only an inch or two, keep the water running.

• Radishes germinate and grow quickly. By the time you harvest garden radishes, weeds do not have a chance to become a problem.
• If you grow daikon, good weed control will be important for good yields and quality.
• Mulching with three to four inches of herbicide-free grass clippings, weed-free straw, compost, or other organic material will keep soil moisture and contain weeds, decreasing the need for frequent cultivation.
• Start cultivating with a hoe or other tool to remove weed seedlings while they are still small.
• Do not cultivate too deeply or you may damage the roots. Use a hand tool or a hoe, and cultivate just deeply enough to cut the weeds off below the surface.

Garden radishes are usually ready for harvest three to five weeks after planting. You can pull them any time they reach a usable size. They will get fibrous and develop a strong taste if left in the ground too long. Remove greens and wash roots well.

The daikon’s shoulders, or the top of the vegetable, typically stand up out of the soil, so the width of the root will be obvious. Spade or fork underneath the planting to harvest long daikon roots without breaking them. Remove the greens and wash the roots.

Daikon and garden radish will only keep for a week or two in the refrigerator. They lose moisture and become shriveled.

• Flea beetles chew small, round holes in leaves. They tend to be a bigger problem early in the spring when radishes are young.
• Cabbage maggots feed on the roots, tunneling into radishes.
• Wireworms can burrow into radishes, creating tunnels.

Many of the same cultural practices help prevent a wide variety of radish diseases.

• Alternaria is a common disease that causes spots on leaves.
• Black rot causes yellow triangles on the edge of leaves, and can cause plants to rot.
• Clubroot attacks the roots, causing roots to become stunted and small.

• If radishes are planted too close together, roots and harvestable radishes do not develop.
• Radishes can develop an overly hot taste when they grow slowly.
• Uneven moisture can cause radishes to crack or split as they grow.