Green roofs are not maintenance free, so like any exposed area, a sedum roof will need some level of maintenance. Once established, your sedum roof will only need a bit of love and attention maybe once or twice a year. However, special attention may need to be given if you’ve experienced a particularly harsh period of weather or if you have a very large green roof.
Some green roof growing mediums can be poor at holding onto its nutrients. So though, you may get a very good growth in the first year, in subsequent years the quality of growth diminishes. The Riefa Board is a unique 100% organic, lightweight growing medium and has been found to encourage good sedum growth and flowering, year on year. However, heavy and persistent rainfall can wash out some of the goodness in the substrate.
Your plants can tell you about their condition. For example, if the number of flowers on your roof is considerably down on the previous year or you can see bare patches. In this instance, an appropriate slow-release fertilizer could be added in the early spring to give improved plant growth. It is also worth noting that if you’ve experienced an abundance of flowers the previous year, then this too could cause your substrate to become exhausted of nutrients.
We’re not just talking about crisp packets and plastic bags here, but also, things like leaves, twigs and other dead plant material. All of these can block rainwater outlets or block sunlight to your plants. You can easily clear away most of this detritus at the same time you decide to feed the sedum roof.
A weed is essentially any plant growing where you don’t want it to. These weeds could include grass, moss and even tree seedlings. Tree seedlings, if allowed to get established can be particularly damaging to your green roofing system. Essentially, if you want your sedum roof to thrive and be healthy, then it is vital that you remove those unwanted plants as they will naturally compete with the sedum for nutrients, light and water.
Sedum coverage on your roof may vary, but a healthy roof will reveal a dense canopy without any bare patches. Bare patches can be a result of natural wastage and can provide an opportunity for invasive species. It is normal to experience a tiny amount of plant failure while your sedum gets established. However, bare areas can also be a sign that your sedum needs a nutrient boost or perhaps there is an underlying drainage issue. The good news is that if the patches are quite small, then in all likelihood, the sedum will naturally spread and re-establish themselves once you have resolved any issues. Alternatively, you could take one or two cuttings from a healthy plant and use those to restore full coverage by plugging them in to the bare patch.
Buying Sedum for Your Green Roof
It is worth noting that though sedum is generally considered to be hardy, it is best to purchase your sedum as locally as possible. Sedum bought from abroad will have become acclimatised to a different environment. Therefore, we advise that you look to source your plants from a local or reputable supplier who has carefully sourced their sedum. Please phone Riefa about our sedum blanket delivery service on 0844 057 0359
Consider Your Safety
The nature of a sedum roof is that it is high up. So, if you intend to carry out the maintenance work yourself, then do take the necessary precautions including securing your ladder.
It is important to use a high quality growing medium for your green roofing project. If you need to discuss your green roof project with an expert, please contact Riefa Green Roofs on 0844 057 0359.
Thursday 9th of June 2016
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Riefa® Board is a unique ultra light weight roof greening product. The first and only green roofing system suitable for both new build and legacy roof projects. Ideal for sedum roof or bespoke planting.