All spinach is harvested mechanically. Spacing is often determined by the demands of the harvesting equipment and the width of the cutter on the harvester. Final stands should be 7 to 8 plants per foot, although 10 plants per foot is acceptable. Thinner populations will enhance control of foliar diseases because of better air circulation. The plants will also be thicker and blockier.
Spinach responds to lime.
It is important to keep the pH at 6.5 to 6.8. A soil test can evaluate the nutrient status of the soil and will indicate the proper fertilizer recommendations. While many nitrogen recommendations call for 125-150 pounds of actual nitrogen, extensive grower experience indicates that as much as 200 pounds is necessary for yield, color, and quality. Ammonium nitrate is the preferred nitrogen source because it does not drive down the pH as quickly as Ammonium Sulfate. To avoid burning the foliage, it is critical to make topdress applications when the spinach plants are dry.