How to build a green roof?
We find more and more roofs or terraces at the top of buildings or modern houses with a sedum cover, this is an installation that is better to let professionals do. But of course, it is also possible to vegetate small garden constructions such as garden sheds, garages, or even dog kennels, whose roof is not always pretty and that you can easily dress up yourself. with a vegetal coat.
- First step – The frame: It is advisable to create a wooden frame around the perimeter of the roof. Its height will depend on the thickness of the substrate, a layer of about 5 cm is sufficient for sedum. If the roof is very steep, you can add intermediate sleepers to better retain the earth. The waterproofing of the roof is then reinforced. For this, we will use a tarpaulin that will go up along the frame.
- Second step – Drainage: Even with a sloping green roof, it is necessary to add a simple drainage system to avoid stagnant water which adds weight to the whole and could cause the plants to rot. You will use a molded polystyrene plate that will have to be drilled at the level of the drainage, in the lower part of the frame so that the water drains at the level of the gutters. Then just add the substrate and sow the sedum seeds.
Note that a green roof does not fit on just any roof. The structure must be strong enough to support the weight of the entire installation and the slope must not exceed 35 °. Conversely, if you do not have a slope, you will need to create one to allow the water to flow properly.
– BUY SEDUM SEEDS MIXED —
How to sow Sedum seeds properly?
When to sow To sow your sedum seeds, prefer spring, between late April and early June. In summer, sowing is not recommended except for shaded and watered sowing. As soon as the hot weather ends (around September), sowing becomes possible again. However, beware of late summer thunderstorms which wash away the seeds.
Soil preparation: This is undoubtedly the most important step. Indeed, the seeds of sedum are very fine, the soil preparation must therefore be well done and especially adapted to this particularity. So avoid a surface that is too irregular, with too large clods. In addition, sedum appreciates well-drained soils, so do not hesitate to add sand or pozzolana to improve its structure.
Sowing the seeds: Sow on a well-ripened soil, having previously mixed the seeds with sand in order to obtain an even distribution. Count 1 gram of seeds for an area of 3 to 5 m2. Do not bury the seeds, simply “fill them in” so that they make contact with the earth. You can use a roller or a flat shovel for example.
Watering and germination: If you want to facilitate germination, you can water in very fine rain. Water little and often until emergence. If water and heat combine well, the emergence is quite fast. Then the growth can be slow and depends on the fertility and the climate. After the seeds emerge, gradually limit watering so that the plants get used to the conditions and rainfall in their surroundings.
How to maintain sedum in the long term?
Sedum is an ideal plant even for beginners in gardening, because it does not require special maintenance! Once firmly in place in the soil, it suffices to let it live quietly from spring when the growth resumes, until winter, when the flowering stems wither by themselves. It is possible either to cut them lightly or to let them destroy themselves naturally, which will protect the foot a little from the frost. Only one thing is imperative: never allow water to stagnate at its foot, which will undoubtedly make it rot.