Autumn is a brilliant time of year for planning and planting a sedum roof.  A sedum roof will insulate a garden building against cold, protect the waterproofing from frost damage and provide overwintering quarters for a wide range of minibeasts.

If installed in the autumn, a green roof will settle and establish itself over the winter months ready to burst into growth next spring.

Alan Titchmarsh creates a sedum roof for his “Love your Garden” TV Show

How to design a green roof for your shed

Designing a green roof combines the imagination of a garden designer with the structural knowledge of an architect.

First and most important step is to make sure that the roof is strong enough to support the plants and their growing medium.  If you are thinking of using sedum matting, then allow for a loading of 60Kg per square metre for the green roof build up with a bit more for live loading (that’s snow or someone walking on the roof to maintain it).  For a deeper layer of growing medium and a more diverse range of plants, the roof will need to be even stronger than that…..a 10-15cm deep layer of growing medium will weigh in the region of 250Kg per square metre.

Good plant choices for a green roof

Next, choose your plants wisely.  Think about how much material they’ll have to root into (deep rooted plants won’t like shallow growing medium), how big they will ultimately grow,  how much maintenance they’ll need and whether they’ll enjoy the conditions on the roof….remember that the higher off the ground you are, the stronger the wind, hotter the sun and colder the frost will be.

Is there irrigation on the roof?  Will the plants you’re thinking of cope with drought?

sedums are great plants for green roofs

Are you considering a wildflower meadow?  If so, the grass will need mowing at least once a year, is the roof access good enough?

Good plants for 10 cm depth of growing medium are; sedums, sempervivums, thyme, sage, periwinkle, selfheal, common daisy, chives, yarrow, scabious, fescue grasses, hawkweeds, birdsfoot trefoil, and bugle.

For planting into a shallow rooting medium that will put less strain on the building, sedums, sempervivums and the very beautiful meadow saxifrage are excellent choices.

The simple way to make a green roof

There are many different ways to create a living green roof and many different plant species that will adapt themselves to life at a higher level but if you’re new to green roofing or looking for a quick and simple solution to the problem of how to prettify a garden shed, look no further than Enviromat’s green roof kits.

This green roof build up is easy to install, gives immediate plant coverage (there’s no waiting for seeds to germinate or plug plants to establish and spread), is one of the lightest systems on the market and is very competitively priced.

Simply choose between our pitched roof or flat roof options, select the right size and order online for delivery within 3 working days.   Full instructions come with the kit or you can download our guide to green roofing from the Enviromat website.

Creating your green roof in autumn will mean plenty of wintertime foliage followed by a beautiful floral display from late spring onwards, and the shed or summerhouse will be a little bit warmer and a little bit more useable during the chilly season.