Abstract: The invention is related to a method and device to grow bulb-crops for Cut-flower-production, like tulip bulbs or daffodil-bulbs. The device is constructed with a growing substrate, like a layer of mineral wool, including supportive means to position the bulbs to grow upright in the substrate. The device of substrate has gabs and or channels under the bulb, to create rooting-chambers or root-channels, to store and guide the roots of the bulbs. The invention shows also a method to grow commercial flower bulb crops.