How to Fertilize barberry-leaved rose?
Rose fertilizer every two to four weeks from spring through late summer

barberry-leaved rose · Rosa persica
Grow in fertile, humus-rich, well-drained soil in full sun. Mulch with well-rotted organic matter in late winter or early spring, and for best flowering apply a general rose or shrub fertiliser in early spring and again in early summer. See rose cultivation
Rose fertilizer every two to four weeks from spring through late summer