Roses are one of the most timeless, beloved flowers. They are stunning as cut flowers or as focal points in the landscape. Not difficult to grow, these gorgeous plants just need regular care. Roses will thrive with a regular feeding program and produce loads of beautiful, fragrant blooms. Many different types of fertilisers made specifically for roses are available, including water-soluble, granular, organic and inorganic forms.
Start your roses off with organic food in the spring. According to Jill Barnard with the American Rose Society, this slow-release recipe will ensure healthy plants as the soil warms up. She suggests mixing 200 g (1 cup) bone meal, 200 g (1 cup) cottonseed meal, and 100 g (1/2 cup) each of blood meal, fish meal, and Epsom salts for each plant. After watering, apply this mixture to the soil in a band starting about 15 cm (6 inches) from the base and going out to about 45 cm (18 inches) from the base. Work the fertiliser into the first 5 cm (2 inches) of soil and then water again. If mixing up your own rose food isn't your thing, other premixed, commercially produced amendments are available. Paulette Mouchet, former editor of "The Rose Garden" newsletter, suggests using fish hydrolysate to fertilise roses. Fish hydrolysate is liquid and can be applied to the foliage or used as a soil drench. This byproduct of the fishing industry boasts proteins, vitamins, amino acids, enzymes and necessary micronutrients that are readily absorbed by the plant's roots.
Balanced rose food
Balanced rose food is a granular fertiliser that has a blend of nitrogen, phosphorus and potassium, sometimes referred to as "NPK" on the package. A casual rose grower should look for an NPK ratio of 10-10-10 and apply this formula every four to six weeks until late August. A 10-10-10 formula means that the fertiliser contains 10 per cent nitrogen, 10 per cent phosphorus and 10 per cent potassium. The rest is filler material. Roses require a constant supply of nitrogen (N) for green leaves and vibrant blooms. A nitrogen-starved rose will often exhibit yellowed leaves and stunted, pale blooms. Phosphorus (P) is an important element needed for a rose to develop strong roots and an abundance of flowers. Potassium (K) ensures strong stems, vibrant growth and well-developed buds. Although the flowers are the focus of any rose plant, it requires 25 to 35 leaves to produce one rose bud so it's important to keep the leaves healthy as well.
Liquid fertilisers, such as Miracle Gro, are convenient for homeowners that have a large number of plants to feed. This plant food can be applied using a hose-end sprayer. The sprayer has a dial on it so homeowners can adjust the concentration of the fertiliser. Follow the instructions from the manufacturer when mixing up and applying liquid fertilisers. If you only have a few plants to feed, 1 tbsp of the liquid fertiliser is generally dissolved in a gallon of water for each plant. Miniature roses should receive a more diluted version -- 1 tsp dissolved in a gallon of water. Give the miniature roses about a quart of this formula per plant. Liquid fertilisers have one drawback. Since they are water-soluble, they can wash away during the hot summer months when roses need to be watered often. Granular fertiliser may be a better choice during the hot summer months.
Another convenient option is to use timed or controlled-release plant food, such as Osmocote. These products are encapsulated fertilisers that release their nutrients slowly -- usually over two to eight months. Soil temperature and moisture level influence the release rate of encapsulated fertiliser. Apply controlled-release fertiliser in May. Although you should follow the manufacturer's directions, generally each plant should receive about a half cup. Like the granular fertiliser, this should be lightly worked into the soil in a band starting about 15 cm (6 inches) away from the base of the plant. Controlled-release fertiliser is another convenient option for the casual rose grower, as it may only need to be applied once or twice throughout the season.