Uniform seeding depth is important for uniform maturity. Fertilization Apply according to soil test. Radishes require high levels of nutrients due to the short growing season and small root system. Apply Boron at 2 pounds per acre. Irrigation Anything that restricts the rapid growth of radishes results in pithy, cracked, harsh-tasting roots.
Ample moisture is the most easily controlled factor in growth.
Radishes require 1 inch of water per week. Weed Control Dacthal and Roundup are the only herbicides labeled for use on radishes. Generally, no chemical weed control is used due to the short growing season. Mechanical cultivation is kept shallow to avoid root damage. Nematodes Radishes are susceptible to nematode damage.