Provide fertilizer “Fertilize with horn shavings, horn meal or brown grain until the plant starts to flower. After flowering, the bulb ripens and the fertilizer is no longer absorbed. Often the leaves begin to turn yellow and wilt shortly after flowering. Even if it is not decorative, you should wait to cut off the foliage until it has completely wilted. This is because the plant stores nutrients in the bulb until then. It is best if the plant sheds the leaves itself. If you cut too early, the flowering energy for the next year will be stolen.
Planting tip: It is advisable to plant the ornamental onion in the background or together with perennials such as lady’s mantle, geranium, peonies, catnip, then you won’t see the yellowing leaves and the perennials will cover the space that is freed up. The best time to plant ornamental onion is autumn, and choose a sunny or partially shaded location. Fill the bottom of the planting hole with sand or gravel as a drainage layer, then plant the bulb. Please leave the bulbs in the ground even after flowering, they are very hardy.”