Once you have invested in a green roof, you’ll want to maximise its performance throughout its lifespan. And that, means investing in regular maintenance. For most extensive green roofs, two to three maintenance visits per year are advised. You’ll need to check the structural integrity of the roof, drainage systems, irrigation systems and, of course, the health and vitality of the vegetative layer.
Every green roof will have slightly different maintenance requirements depending on its build up and its intended function. But there are some green roof maintenance tasks for autumn and winter that will apply to every living roof.
Our handy guide will ensure that you don’t miss any vital green roof maintenance task this autumn and winter. I’m sure you don’t need the GRO team to remind you to take care working at heights, especially in wet or windy weather.
If you are at all worried about the logistics of maintaining your green roof, please don’t hesitate to get in touch with the board. We will be happy to put you in touch with a reputable green roof maintenance provider.
Autumn Winter Maintenance For All Green Roofs
- Ensure fall restraint system has been tested and certified for use
- Look for any damage to the structural integrity of the roof and instigate repairs as soon as possible.
- Clear away fallen leaves before they can restrict the amount of sunlight available to the plants. Ideally they should be removed before the organic matter starts to compost – it’s never a good thing to have too many soluble plant nutrients on a green roof.
- Clear debris from drainage outlets and check that excess water can leave the roof unhindered
- Remove vegetation from all pebble/gravel borders and fire breaks.
- Look for unwelcome plant species such as tree seedlings or buddleja and remove them
Radmat Green Roof, Olympic Park
Essential Maintenance For Intensive Green Roofs
Intensive green roofs by their very nature will have receive a good deal of care throughout the summer. Autumn and winter afford an opportunity to check and service irrigation systems (if installed). If general wear and tear has led to substrate settlement, now is a good time to top up the levels.
How did your intensive green roof perform this summer? Could it be improved in any way? This is the perfect time of year to plan changes to the planting palette and/or everyday management methods.
Sedum Roof Maintenance Tips For Autumn and Winter
Sedums are remarkably resilient little plants and will need very little attention at this time of year other than clearing away fallen leaves.
If you are seeing bare patches of substrate and you’d prefer they were populated with plants, it’s very easy to generate new plants through ‘sprouts’. Simply off break pieces from healthy plants and press them into the bare substrate. If the weather is damp and mild, it won’t be long before they develop roots.
Avoid walking on sedums during frosty weather. You risk damaging the succulent plant cells and it could take a few months for the plants to recover.
Sedum plants often take on a reddish hue during the winter months – this is nothing to worry about. They will green up as soon as temperatures start to rise.
Wildflower Roof Maintenance
On a wildflower roof, maintenance tasks for autumn and winter are all about managing the vegetation. In order to manage nutrient levels (wildflowers prefer a low nutrient environment), it’s important to minimise the risk of plant material composting and adding extra organic matter. If you haven’t already done so, you will need to cut back the spent vegetation and remove it from the roof.
Please be mindful of the fact that many insect species like to overwinter in hollow stems. The GRO Code recommends that vegetation is not trimmed any shorter than 150mm. If possible, leave the spent vegetation on the roof for 24-48 hours to allow insects to re-orientate themselves.
Provided the stems have not flopped over, it’s helpful to leave occasional patches of standing vegetation to create overwintering habitat.
Autumn Winter Maintenance For Biodiverse Roofs
Biodiverse roofs have been designed to be self sufficient. Other that the maintenance jobs that are needed on all living roofs (leaf clearance, drainage checks, weeding borders and removing aliens species etc) you shouldn’t need to do anything to your biodiverse roof other than enjoy it.
Blue-Green Roofs: Extra Maintenance Tasks For Autumn And Winter
Carry out appropriate maintenance to the vegetative layer and do all the usual checks on structure and safety systems. In addition, it’s a good idea to inspect restrictor chambers, orifices and roof outlets.
Who Should Carry Out Green Roof Maintenance?
Every green roof will should be having routine maintenance visits at least twice a year. It’s up to you whether you choose to carry out the work in house or whether you hire a contractor. However, anybody working in green roof maintenance should be trained in working at heights as well as having a good knowledge of horticulture and green roof technology.
Visit the Lantra website for more information on green roof training.
Find a GRO member who can help and advise on green roof maintenance.