Spring Feeding

• Roses need their first feeding in the early spring. When spring arrives, dig in the rose garden. As soon as the soil becomes soft and workable, it is time to provide the initial spring fertilizer application. Granular, all-purpose fertilizers work best for roses because these fertilizers feature a delicate balance between nitrogen (N), phosphorous (P) and potassium (K), recommends Spring Valley Roses. Mix 2 cups of fertilizer into the soil under the roses. Mix fertilizer in a circle around each rose bush.
  
  

Summer Fertilizing

• Spring fertilizing is sufficient for many roses, especially when roses are given the proper amounts of sunlight and water. However, a regular schedule of fertilizing throughout the summer helps elevate a rose garden from basic to beautiful, encouraging perfect blooms. One month after spring feeding, spray each rose with 1 gallon of liquid fish-kelp fertilizer. Repeat monthly throughout the summer. Stop fertilizing roses six weeks before the first winter frost.
  
  

Nutrients

• Proper rose fertilizing involves understanding the nutrients in fertilizer and how those nutrients affect rose bushes. Nitrogen, potassium and phosphorous are the most important nutrients for healthy roses. Nitrogen helps roses grow healthy canes and green foliage. Too much nitrogen can cause a decline in rose blooms, while inefficient nitrogen causes pale blooms and yellow leaves. Potassium promotes lush, thick growth and a lack of it will cause roses to develop brown leaves, weak stems and poorly-developed blooms. Phosphorous is important when roses are first planted. Mix bone meal into the soil when planting new roses for strong roots and flower production.
  
  

Warning

• Roses do not respond well when treated with a chemical-based, liquid fertilizer, according to Spring Valley Roses. Granular and organic liquid fertilizers are best for rose bushes. Chemical-based products sometimes cause fertilizer burn on the rose bushes, resulting in yellow, dry leaves. Most chemical fertilizers contain too much nitrogen for healthy roses.