Somewhat counter-intuitively, the survival of green roof planting is greater in winters with long deep sub-zero temperatures. Being shallow and very exposed to warming sunlight, green roofs thaw rapidly. Frequent freeze-thaw cycles in the early and late winter is associated higher loss of vegetation on green roofs. | Somewhat counter-intuitively, the survival of green roof planting is greater in winters with long deep sub-zero temperatures. Being shallow and very exposed to warming sunlight, green roofs thaw rapidly. Frequent freeze-thaw cycles in the early and late winter is associated higher loss of vegetation on green roofs. |