Roses need regular fertilizing for abundant growth and blooming. However, timing is key: applying the right fertilizer at the right time delivers optimum results.
The best time to fertilize roses is during the growing season – early spring and late summer – when they are actively developing foliage and flowers. In spring, wait until your roses start to break dormancy, then apply a slow-release fertilizer (most have a Nitrogen content of 12-6-12). This will encourage strong root development, lush foliage, and plenty of blooms.
In late summer, several weeks before frost begins to set in, fertilize them again with a fast-release blend (NPK 15-30-15) for a burst of extra energy and nutrients. This will also aid with preparation for winter survival.
Try not to fertilize too close to summer heat waves or if there is an extended period of drought; in both cases, feedings will burn newly emerging shoots or delay the initiation of buds even further. Roses should be given several inches of water before feeding, and avoid direct contact with roots by spreading the nourishment around their base. Keep in mind that while you are supplying them with food, you must also protect them from pests and diseases by frequent fungicide treatments or organic methods like neem oil sprays, etcetera.
After each feeding, really take some time to observe your plant’s situation: watch out for signs that they need more water or show current nutrient deficiencies in order to correct them properly without any harm coming to uproot. Overdoing it won’t do any good, either!