Growing Tillage Radishes

New research continues to support using certain radish types to condition fields during winter, after cash crops are harvested.
radish carrots

radish carrots

white and red radish and carrots

Photo by: totalpics

totalpics

By: Nan Chase

Botanical Name: Raphanus sativus Longipinnatus

Imagine a plant that tills the soil by itself: breaking up compacted ground, helping control pests biologically, and making more moisture and nutrients available for the next year’s cash crops.

The long and robust daikon radish – also known as oilseed radish or forage radish – is that plant. Today it also referred to as tillage radish, and it does even more:

  • Protects topsoil from erosion
  • Controls weeds
  • Adds organic matter to soil
  • Reduces dependence on chemical fertilizers
  • Helps warm the ground in spring

In northern climates especially, sowing fast-growing tillage radish seeds in fall after cash crops are harvested allows the plants to grow to maturity before heavy frosts shuts down all agricultural activity.

Especially in the coldest climates, winter “kill” will make the radish roots disintegrate. The holes that remain in spring have an effect like tilling: moisture and new crop seeds can find places to settle in.

The oilseed radish can actually break hard packed soil apart organically. These radishes grow a slender taproot that penetrates the soil as deep as six feet. Meanwhile the plump upper part of theradish root can grow several inches in diameter to a depth of nearly two feet. That’s why tillage radishes are sometimes called “bio-drills.”

Growing tillage radishes as a form of “conservation tillage” takes extra time and work in the farming cycle. For one thing, timing must be right to plant the tillage radish seeds; tillage radishes need about 60 days to mature and produce their big, beneficial roots. And in low-frost zones the radishes must be “terminated” several weeks before planting new crops, so that no roots or seeds are present to resume growing.

Researchers are starting to study tillage radishes in detail. So far they are finding that growing radishes for tillage probably doesn’t affect the ability of cash crop seeds to sprout. That’s good news. And breeders are exploring ways to produce the most useful tillage radish seeds. Farmers will find several patented hybrids for tillage radishes.

Some growers are also experimenting with mixing tillage radish with other over-wintering cover crops, notably oats. The results are promising.

Tillage radishes are proving effective at weed suppression in fields. To achieve best results, plants should grow at a rate of five seeds or more per square foot. And seeds should be planted asearly as possible in fall.

An important benefit of growing tillage radishes is that the roots can draw up, or “scavenge,” nitrogen from surrounding soil, preventing it from leaching away and making more nitrogen available for crops to follow.

Two notes of caution: tillage radishes don’t grow well where the soil it too wet, so make sure that there’s enough drainage where you want to plant. And radish roots decomposing in a late-winter field can produce strong rotten egg smells.

Keep Reading

Next Up

Growing Turnips

For thousands of years, colorful turnips and their leaves have been an easy-to-grow staple cool-weather vegetable with few pests or problems.

Growing Red Radishes

The red radish is a garden classic: early to sprout in spring, fast to mature, delicious and nutritious. The greens are good too.

Growing Purple Radishes

Purple radishes have bold flavor, rich color, and greens that beg to be used. Include them in any sunny, well-watered vegetable garden.

Growing Radish Sprouts

Growing radish sprouts brings fresh flavor to salads, sandwiches, and more. Proper sanitation and handling are crucial for safety.

Growing Radishes Indoors

If your outdoor space is limited, learn how to grow radishes indoors.

Growing Turnip Greens

In many cultures, including the Southeast US, turnips are grown as much for their tasty, highly nutritious leaves, called “greens” as for their roots. Here are a few tips to get the most out of turnip greens.

Growing Rapid Radishes

Radishes are quick to germinate and grow to maturity, hence the nickname “rapid radishes.”

Growing Icicle Radishes

Looking to keep your cool in summer? Try heat-resistant icicle radishes, known for their ability to thrive in many garden conditions.

Growing Cucumbers Vertically

Cucumbers feel right at home growing vertically, either on a trellis or in a tomato cage.

Growing Spring Radishes

Spring means time to plant radish seeds, but there are many variables to determining just when springtime comes to your area.

Get Social With Us

We love to DIY. You love to DIY. Let's get together.

Consult Our A-Z Guide

Everything You Need to Know

Browse a full list of topics found on the site, from accessories to mudrooms to wreaths.  

How-To Advice and Videos

Get video instructions about kitchens, bathrooms, remodeling, flooring, painting and more.

Watch DIY Downloads Now

Watch DIY Network LIVE

Don't miss your favorite shows in real time online.