Chicago is home to the Daniel F. and Ada L. Rice Plant Conservation Science Centre, Chicago Botanic Garden, and it features a 16,000 square foot green roof garden. The green roof is split into sections so the Centre can carry out a variety of research projects, and it is from this that my inspiration started. 

I do not have 16,000 square feet of roof space like the Science Centre in Chicago, but what I do have is a potting shed, and that shed has a roof. 

Potting Shed Roof

Since getting my modest potting shed, I have been determined to make the space as versatile as possible. When looking at it from my office window, I knew that a green roof would be a space that is beneficial for wildlife.

Throughout the country there are a number of companies providing green roofing and a high percentage of that is sedum green roofing. I adore sedum, and a sedum green roof provides an excellent habitat, year round colour, and an excellent space for pollinators. 

I did have a worry though, due to the Scottish climate and the amount of rainfall we have. I found a company called Green Roofs Direct, based in Ireland, who produce sedum green roofing under conditions similar to ours here in Scotland. 

This green roof came with a beautiful blend of sedum with, for example, Sedum hespanicum, Sedum reflexum, and Sedum album ‘Coral Carpet’. What is most important though is that it is 1 year minimum matured and hardened with 365 days of sea salt exposer, 1061mm of rain water, 60+ mph winds, and 72 minimum days of frost or snow – this suits our Scottish climate perfectly!  

Installation

For installing the sedum roof, I made all the trims using larch timber to build up the sides of the roof in order to house all the materials and sedum. Once made and secured, I laid down a waterproof membrane, a wool sheet that was included in the kit, enough substrate for 20mm thickness, which was also included in the kit, and finally the sedum roll. 

Water Collection

The shed roof is pent, meaning it is at a single angle, and as gravity drains the water to the lowest point of the roof, I have installed a gutter and water butt. The trim at this lowest point has holes drilled through for the passing of water to the gutter, and this trim is backed with geotextile membrane which will stop any debris from passing through.

Finally, I have placed some large rocks between the drainage trim and the sedum roll to act as a separation barrier.

If you have an outbuilding or shed that could take a green roof then this is a great option, and I didn’t even mention its insulation and sound reduction properties! It has increased my green space, is benefitting nature, and every time I catch a glimpse of it from the window, I cannot help but smile.

Andy Peasgood was a Principal Dancer with Scottish Ballet and is a keen gardener. His performance career was fast paced and he finds balance in the garden with particular interests in planting, wildlife and design. You can follow Andy’s progress as he builds ‘A Garden from Scratch’ in his regular column in Scotland Grows magazine and keep up to date with him on his Instagram feed.