Gardening trends may come and go at a dizzying rate, but some plants and flowers retain their timeless beauty, and whether your garden is large or small, traditional or modern, it can always benefit from the addition of a few beautiful rose bushes. As well as being attractive, rose bushes are also surprisingly hardy, and despite their fickle reputation, you can usually find a rose variety that will grow in any type of soil or level of shade.
However, even roses planted in the most nutritious soil will need a little boost from time to time to remain at their best, and a wide variety of garden fertilisers specifically designed for rose bushes can be purchased from garden fertiliser suppliers. These fertilisers aren't all created equal, so to ensure the fertiliser you choose gives your roses the best possible chance of growing and thriving, look out for the following key qualities of a good rose fertiliser:
High phosporous content
Phosphorous may be most well known as the substance used to make match heads, but it is also a vital nutrient for healthy roses (as well as healthy humans). Roses bushes use phosphorous to create strong root systems and large flower blooms, and plants with phosphorous deficiencies tend to have dull, greyish foliage and flower buds that do not open to their full potential. Since phosphorous is so vital for root growth and the bush's ability to take in water, fertilisers rich in phosphorous are particularly important for plants planted in dry, sandy soils.
High potassium content
A nutrient essential for healthy growth in almost all plants, potassium-rich soils grow hardy rose bushes with strong immune systems that are capable of withstanding insect attack, leaf diseases, droughts and other energy-sapping events. As such, potassium is just as important as phosphorous for helping roses grow in drier soils and is particularly important for roses growing in organic gardens that do not benefit from insect-killing pesticides.
High nitrogen content in summer
Nitrogen is probably the most important soil nutrient for any green plant, not just roses, as it is used to create the chlorophyll that allows green plants to photosynthesise sunlight into energy—without it, your roses will quickly yellow, wither and die. Most soils contain a certain amount of nitrogen, but this is routinely washed away as water passes through the soil, so nitrogen-rich fertilisers should be added to your soil frequently during the summer months.
Low nitrogen content in winter
Nitrogen becomes less important to your roses during the winter months, since there is less natural light for them to synthesise into energy. Adding excessive nitrogen at this time of year can force roses to divert energy away from root growth and into useless leaf growth, leaving them more vulnerable to cold snaps and exhausting them before the warmer months return.