When Do I Stop Feeding My Roses for the Season?

Care

• Mulch is often recommended for use around roses to preserve soil moisture. Mulch also has an insulating effect on soil, preventing it from getting too hot or too cold. But mulch may have a detrimental effect on soil as well. Organic mulches may change the way nitrogen is absorbed into the soil, requiring you to use more fertilizer as a result. Fertilizers used during the growing season help to enrich the soil, but as roses approach dormancy the nutrients need not be applied.

Fertilier Application

• Unless there is a nutrient deficiency in soil, a balanced, general purpose fertilizer will suffice for roses. Use a 10-10-10 or 12-12-12 mixture when applying fertilizer to the soil, approximately 1/2 cup per plant. Fertilizer may be applied to the soil by hand, in a ring around the plant. Spread the fertilizer starting 6 inches away from the base of the plant and lightly spread it around the ground in a circle approximately 12 inches wide. Water the soil thoroughly after applying fertilizer so it will soak into the ground.

Schedule

• Fertilize roses in early spring at the start of the growing season. Roses should be fertilized again in mid-June, which is the beginning of the summer season. Roses that continue to flower through the summer should be fertilized for a final time in mid-July. Do not apply fertilizer later than mid-August. Fertilizer encourages new growth; if any occurs in late summer it is sure to be damaged by cold winter weather. Instead, apply fertilizer in late fall after the plants have already gone dormant. Fertilizing roses that are fully dormant is not harmful, and helps to enrich the soil for the coming spring. Potassium-rich fertilizer even helps to strengthen the plant against the winter cold.

Secondary Fertilizer

• Slow-release fertilizers should be applied in spring around May. Fertilizers that release nutrients into soil slowly over time may still be active during the late summer if they are applied to soil after this point. Some gardeners use Epsom salts as a secondary rose fertilizer because it releases magnesium sulfate into the soil. Even secondary fertilizers may not be applied late in the summer season, and should only be applied in spring or early summer.