How to Grow Spanish Radishes

Till the planting site to turn the soil and expose rocks, roots and other debris near the surface. Cart them away. Root vegetables such as Spanish radishes require an underground free of obstacles.

Distribute a 2-inch layer of manure or compost over the planting bed and incorporate it into the ground with a shovel. The organic matter helps to create the well-drained and loose soil structure that radishes require.

Broadcast three pounds of a 5-10-10 fertilizer per 100 square feet on the seedbed. Work the nutrient into the soil with a shovel. Blend it uniformly to prevent fertilizer burn on the roots. Rake the planting surface to smooth it out.

Sow the Spanish radish seeds one to two inches apart, half an inch deep. Separate multiple rows by 18 inches. Thin the seedlings to four inches apart.

Irrigate the seedbed at planting and continue to maintain the soil hydrated through germination. Give the developing plants water sufficient to reach six inches deep. Irrigate whenever the surface begins to dry. Morning is the ideal time, as the moisture quickly evaporates off the foliage under the warming sun, preventing diseases.

Apply a 2-inch layer of straw or grass clippings around the Spanish radish plants to suppress weeds and slow water evaporation.

Harvest Spanish radishes 55 days after planting them. Pull the roots out of the ground by hand before the soil freezes.