Radish Soil Requirements

Soil Consistency

• Radishes grow best in friable soil that allows the roots to readily emerge. Friable soil is that which can easily crumble into small pieces and does not form clods. Sandy, sandy-loam or light mineral soils are ideal for radish growth and allow for quick production. Muck soils may also be used because they are rich in organic matter and have a high water capacity. Remove any large objects from the soil bed prior to planting seeds. Rocks, dirt clods or undecayed organic substances could interfere with root development and should be removed.

Soil Fertility

• Due to their rapid development, radishes need access to soil containing plenty of organic nutrients including nitrogen, phosphorus and potassium. One surefire way to achieve this is by working in dead leaves in fall, prior to spring planting, which incorporates organic matter into soil that quickly breaks down. For larger acreage, North Carolina State University horticulturalists recommend 50 pounds of nitrogen and 100 pounds each of phosphorus and potassium for every acre planted, unless that soil was heavily-fertilized previously. Test the soil before amending with nutrients. Add boron to soils which may be lacking in this substance.

Soil Temperature

• Radishes will germinate in a range of temperatures, from 45 to 90 F, but the best temperature for emergence is 85 F. Once radishes are growing, they prefer a soil temperature of 60 to 65 F for best results. Plant in winter if you live in a mild climate, or in early spring and fall if you live in a cold location.

Other Soil Conditions

• Radishes thrive in soil that is at a pH of 6.5 or higher and that is cool and evenly moist. Do not allow the soil to dry out at all after planting the seeds and distribute irrigation evenly. Any interruption to radish growth can harm development due to the speed with which the crops grow. For many radishes, including Cherry Belles, soil does not need to be very deep for adequate root growth. Some varieties, however, such as Daikon radishes, need deep, friable soil to send their long root.