Radishes: All Tops But No Root

Radishes: All Tops but No Root - Solution Guide

Healthy Top Greens with No Roots

This is one of the most common complaints from gardeners of all experience levels. It is a frustrating phenomenon, but the good news is that the gardener can avoid or prevent this disorder. There are several reasons this can occur, all due to abiotic factors.

The Soil is Too Rich

  • Especially in nitrogen. Higher phosphorus and potassium with less nitrogen is best.
  • When root veggies have more nutrients than they need, they are not interested in forming thick roots and only grow full foliage.
  • Have a soil test done. Nutritional imbalances can be frustrating to overcome, but having true soil test results gives you a place to start when adding or adjusting fertilizer to the garden. You never want to do this indiscriminately.

Lack of Thinning

  • Radish plants grown too close together can lead to big tops and no roots.
  • When each radish top gets so large, they compete for resources like sunlight, water, and nutrients. Big leafy plants can start shading one another out.
  • Thin radishes to at least 2 inches apart. If the radishes grow vigorously, thin them more to try and avoid this problem. If you thin them 3-4 inches apart and this problem continues, then you know it is one of the other causes.

Lack of Sunlight

  • Radishes require full sun.
  • Radish plants with limited sunlight due to structures, shade trees, or crowded plants can lead to big foliage with thin to no root development.

The Weather

  • Specifically, heat is a problem for radishes.
  • Radishes are a cool-season crop, meaning the optimal temperature for bulb production is between 50°-70°. Once temperatures go too high, radish plants can go from a vegetative state to a reproductive state, which prevents root development and ultimately favors flower production or bolting.
  • The most straightforward way to avoid this is to plant radishes sooner in spring. A second crop can also be seeded for a fall crop in late summer.

NOTE: Healthy greens with no root production, such as radishes, beets, carrots, or any other root-type vegetable, have nothing to do with the planted variety.

NOTE: These types of production issues NEVER relate to a seed issue. All a seed can do is germinate. That's it. All other physical, flavor, or yield qualities are ONLY influenced by environmental or cultural factors. This is true for all fruit and vegetable types.