Fact Sheet Fertilizing Roses

Fertilizing RosesThroughout history roses have captivated the hearts and minds of gardeners and non-gardeners alike, inspiring the creation of numerous poems, legends, and books on their uses and care. They are one of the most popular garden flowers grown on the face of the earth as evidenced by the several garden clubs, societies, organizations, and businesses devoted to them. There are countless species and cultivars available in a wide range of colors and forms, with new cultivars being introduced each year to improve on the previous year's selections.With the abundance of information available on roses and rose care, there is still some mystery about their proper care and maintenance. For every different type of rose available, there is probably a gardener with a different approach to caring for roses. It is as much of an art as it is a science to growing beautiful roses, but the following information will give you some important basics to help demystify the process. This fact sheet will discuss fertilizing, pruning and winterizing roses.FertilizingBecause roses are heavy feeders, a routine fertilization program is important for plant health and vigor. To provide the proper nutrients for your roses in the amounts needed for optimum growth, it is important to first test your soil to determine its pH, texture (i.e., clay loam, sandy loam), and existing mineral nutrient content before adding fertilizer. A soil test kit can be obtained by calling your county Extension office. The amount of fertilizer and types of amendments you apply will be determined by the results of the soil test. Following the recommendations will assure you will neither over nor under fertilize your roses. A soil test should be done prior to planting and every two to three years thereafter.Roses grow best in the pH range of 5.5 to 7.0. Soils testing below 5.5 will need an amendment of dolomitic lime, 7 to 8 pounds per 100 square feet, to raise the pH into the desired range. Powdered sulfur can be used to lower the pH. For soils with a pH between 7 and 7.5, add one pound of sulfur per 100 square feet; for a pH between 8 and 8.5, add two pounds of sulfur per 100 square feet; and for soil with a pH over 8.5, add three pounds of sulfur per 100 square feet. Ohio soils are often deficient in iron when the pH is above 6.5. Iron sulfate can be used instead of powdered sulfur to decrease the pH and provide the needed nutrient. Also, chelated iron products are available for foliar feeding or soil application.Soil texture, which is the relative percentage of sand, silt and clay composing soil, will influence the amount and frequency of fertilizer application. Sandy loams, for instance, will require more frequent applications because they drain rapidly, leaching essential nutrients. They contain little clay (and possibly organic matter) that would normally hold nutrients.It is always a good idea to amend your soil with organic matter, such as humus, peat moss, manure or composted sewage sludge for an added source of slow release nutrients. The addition of organic matter will also improve the soil's drainage and nutrient holding capacity. It is recommended that two to four inches of organic matter be added and worked into new beds to a depth of 12 inches. Many gardeners find the combination of organic materials and a fast release, complete, inorganic fertilizer, such as a 5-10-5, 10-10-10 or 12-12-12, works best to produce beautiful roses.In general, roses do well with an application of 3 pounds of actual nitrogen per 1000 square feet (or 0.3 pounds of actual nitrogen per 100 square feet), divided into three applications per year. Call For Price 440-320-7854