Roses are somewhat picky about soil nutrients, so fertilizer is usually necessary for healthy rose plants. Organic fertilizers tend to cost more than inorganic ones, but they have the benefit of improving soil texture along with adding nutrients to the soil. They also have lower nutrient concentrations, reducing the occurrence of polluted runoff. Many gardeners could stand to have the better soil texture that comes along with compost; coastal areas tend to have overly sandy soils while many inland areas have heavy clay soils.
Basic Organic Fertilization
Prepare the soil before planting new roses by adding some compost, composted bark and manure to the planting holes. Add a couple handfuls of manure, and amend the topsoil so it is a quarter compost and a quarter composted bark. This step is especially important for gardeners with heavy clay soils.
Water deeply after planting the roses.
Fertilize the roses during spring using a balanced organic fertilizer. Some balanced organic fertilizers include compost and alfalfa meal. Alternatively, you can try another type of organic rose fertilizer from a gardening store. Apply the fertilizer when the plant first starts growing new leaves in spring. When using compost, you can apply a couple inches of compost to the top of the soil around the base of the plant, starting about 8 inches away from the stem.
Water to help the nutrients settle into the soil.
Repeat steps 3 and 4 two more times, once in early summer and once in late summer. Fertilize for the second time after the roses bloom in spring, and then fertilize again one month to six weeks later.
Soil Testing and Specialized Fertilizers
Consider performing a soil test using an at-home testing kit or by sending a soil sample to a local nursery or university for testing. Soil tests are especially helpful before planting roses in a soil of unknown quality or if roses are growing poorly. A soil test will reveal which nutrients the soil lacks, so you can add an organic fertilizer that contains more of those specific nutrients.
Add an organic fertilizer, depending on the soil needs. The primary nutrients that roses require are nitrogen, potassium and phosphorous. Fertilizers have an N-P-K ratio that explains how much of each element the fertilizer contains. Blood meal has a 13-2-0 ratio with plenty of available nitrogen, and fish meal is also high in nitrogen. Bone meal provides readily available phosphorous, and Sul-Pol-Mag is an organic fertilizer with readily available potassium.
Water the roses after applying the fertilizer.
Things You Will Need
- Composted bark
- Aged manure
- Alfalfa meal (optional)
- Soil testing kit
- An organic mulch around the base of rose plants helps provide consistent soil moisture as well as some soil nutrients.
- Use aged manure, because fresh manure can burn rose plants.
- National Gardening Association: Planting Roses
- National Gardening Association: Growing Roses the Natural Way
- Rose Magazine: Organic Rose Fertilizer
- University of Missouri Extension: Fertilizing Roses
- University of Illinois Extension: Water, Mulch & Fertilizer
- University of Missouri Extension: Roses: Care After Planting
- Jupiterimages/Comstock/Getty Images