People usually associate extensive green roofs with Sedum plants and often talk about sedum roofs instead of green or living roofs. Why is this so? Why is Sedum the best plant for living roofs?
SEDUM, SUCCULENT, FATTY Succulents are plants that store water in part of the plant. Sedum stores water in the leaves and this is why it is often referred to as a leafy succulent. Due to its natural properties, Sedum needs minimal care as part of a green roof: it requires little (rain) water and nutrients. Sedum is a large genus of flowering plants in the family Crassulaceae (Fat Plants), also known as fatbergs. The natural properties of Sedums, mainly their drought tolerance and ability to thrive in harsh environments, make these succulent plants ideal for use in green roofs.
WHY ARE SEDUMS SO SUITABLE FOR GREEN ROOFS ?
Adaptable to climate Sedums are found primarily in the Northern Hemisphere, particularly in the Mediterranean, but also in North Africa and South America, where they inhabit arid and/or cold regions where water is scarce. Sedum can store water in its leaves and is able to withstand variable, harsh weather conditions (-25°C to 40°C).
Does not require deep soil edum has very shallow roots, which is necessary when the thickness of the growing medium is limited, as is the case with extensive green roofs. The suitability of low-growing sedum species for use in extensive green roofs has been firmly established due to their high survival in thin substrate layers of 2 to 3 cm.
Modified metabolism Sedum absorbs carbon dioxide at night and converts it to malic acid, which is used during the day for photosynthesis. Pores in the leaves open only at night to minimize moisture loss during the hot, dry day.
High tolerance to disease Sedums have low or no probability of contracting diseases or infections caused by parasitic insects .
Low water consumption Sedums are extremely drought tolerant and require little feeding and maintenance compared to most plant species. While other species die from drought, Sedum is able to survive by adjusting its metabolism and minimizing its need for water. Sedum can recover very quickly once it gets some moisture. Numerous studies confirm its high tolerance to drought. Sedum Album (white fathead mint) can survive more than 100 days without water. Other drought tolerant species are Sedum Acre (biting sedum), Sedum Kamtschaticum Ellacombianum, Sedum Pulchellum Michaux (bird’s claw sedum), Sedum Reflexum (curved sedum), Sedum Spurium Coccineum (creeping sedum), and Sedum Spurium Summer Glory, all of which can survive more than 80 days without water.
Low maintenance Sedums don’t just tolerate drought conditions, they are also highly resilient. Since Sedum is able to survive by adjusting its metabolism, conserving water, the same goes for conserving food. In general, adding nutrients once a year is sufficient, but re-feeding allows Sedum to thrive.
High environmental value Sedum species trap dust and air pollutants – fine particulate matter is bound and decomposed/absorbed by plants – PM10 range w/ 0.42 – 9.1 g/m² per year. Several species of Sedums grown together have the potential to process (sequester): 5.87 kg carbon/m² and 215 kg CO2/m² per year.
Constantly changing beauty Having several species of Sedums in the plant carpet allows for dense cover year-round, and the appearance of the plants changes with the season. Many sedum species have periods of dormancy during which they take on variegated colouration. The different flowering periods and colours of sedum species create a sense of ever-changing beauty.
WHAT IS A SEDUM ROOF OR A ROOF WITH SEDUM CARPETS? An extensive green roof or sedum roof is a roof with vegetation that more or less has the properties to self-replicate, maintain and develop on its own. Extensive green roofs have a substrate layer thickness between 4 and 15 cm and a weight of 30 to 220 kg per m2. By putting sedum vegetation on your green roof, you make it more sustainable. In addition, unlike an intensive green roof, you apply a low-maintenance and cost-saving method of greening.
By placing pre-cultivated sedum carpets instead of planting individual sedum sprouts, installation is simplified and this saves you a lot of time. In addition, maintenance costs are much lower as the sedum carpets already have good rooting and require much less water after installation than when planting new plants.
WHY CHOOSE SEDUM CARPETS OR SEDUM ROOFING FROM INNOV TOP GREEN? Our company conducts constant research on the quality of Sedums for extensive green roofs. We gather knowledge and experience in growing Sedums from botany and landscape architecture specialists from all over Europe. Not all Sedum species are suitable for extensive green roofs or plant carpets. When cultivating Inova Top Green’s plant carpets, we select only the most suitable Sedum species. You can be sure that your green roof will stay truly green all year round. For many years to come. Trust us! We create living roofs!