Turn the soil 12 inches deep with a spade. Incorporate 1 1/2 pounds of an all-purpose balanced granular fertilizer, such as 5-10-10, 6-12-12 or 10-10-10, per 50 square feet of space. Do this just before planting your tulips, typically in the fall.
Spread 1 pound of the same all-purpose balanced fertilizer per 50 square feet around newly emerging tulip foliage in the spring. Then, gently scratch into the surface with a rake, brush off any fertilizer that landed on the foliage and provide 1 inch of water. Reapply the same amount of fertilizer in the same manner after your tulips are finished blooming.
Apply 2 or 3 inches of compost on top of the tulip bed each fall after you cut back the foliage. Compost not only helps insulate the soil, it also supplies the soil with a regular dose of nutrients as it decomposes throughout the year.