Sunday, June 7, 2015

Shed with a DIY Living Wall and Living Roof

Small shed with living wall and roof.
After a couple of years of packing the cushions for the bench and deck furniture into the house everytime it threatened to rain, we decided to build a small shed (8x4x7) next to the pond to store them for the summer months.  This was an opportunity to do something I have wanted to do for a long time - play with the a living roof and wall.

After a bit of searching on line and at local nurseries, I decided that a  do it yourself (DIY) living wall was going to have to be the way we went, since the commercially available units were prohibitively expensive.

Because of the weight of wet growing medium, wood and plants we decided to build the shed mostly our of rough cut 2x8 boards, including the roof.  The shed was built with an extensive overhang on one side to provide protection from the rain, but no overhang on the side where there was going to be a living wall.

An EPDM pond liner was used, in one continuous piece to cover the roof and wall (see Fig. 1).  Concrete pads were poured at the two ends and the middle of the shed on the living wall side.  These were to support the weight of the cinder block pillars so they did not push through the EPDM liner.
Figure 1. Schematic drawing of shed and living wall.

 Cinder block pillars were mortared on top of the EPDM liner and strapped to the walls using stainless steel brackets.  Pressure treated 1x6 was used to make the shelves for the wall planting. These were slide into place through the diagonal openings of the cinder blocks.

To fill the gap between the cinder block and the liner covered wall I cut commercial plastic plant flats in half with a box cutter type knife and slide them against the wall. 
Figure 3 showing cinderblock pillars and 1x6 shelves
Figure 2 Showing drip irrigation line.

A drip irrigation system using flexible line was threaded through the wall and tacked with clips into the 1x6 boards, taking care that at least one dripper hole was in the cinder block openings at the ends of the wall.  This was done to ensure that plant set into the cinder block openings at the ends of the wall would get watered.

Figure 4 showing end plantings and brackets.
Brackets were used to fasten the pillars to the wall at both ends.  
We chose to have quite a bit of liner in front of the shed, to prevent the water running off the roof and the wall from going under the shed. The planter that was made in front of the shed is has the EPDM liner in it and plants that enjoyed the constant moisture were used in the planter(Dicentra and Corydalis),

The roof planters were made from pressure treated 2x8, bracketed together to form a box and strapped to the underside of the eaves with brackets, in such a way that the liner was not punctured with screws. 

Figure 5 showing initial planting
Figure 6, newly planted wall season one.
Initial plantings of begonias, sage, and zinnias were only moderately successful, the site was just to shady for some of those species.  The begonias (cv "Griffon") did very well.  The next season the wall was planted with the Griffon begonias, Fringecup (Tellimia grandiflora), fuchsias, Begonia bolivensis, B. fushsiodes and a varegated sedge.  The lower plantings had to be deer resistant species, so Ageratum and Epidmediums were chosen for those areas.  Plants were planted in blocks of individuals with contrasting textures and colours.
Figure 7. Living wall mid season Year 2.

The roof was an opportunity to grow plants that we  can't grow because of the deer in our yard.  Four cultivars of deciduous azaleas, and several fuchsias form the core of the roof planting.  The front of the ground level planter and the area around the shed were faced with paving stones.  

  1.  You need to make sure you have water easily accessible, for us this meant running a new waterline down to the shed. 
  2. The water is on an batter-operated automatic timer, at 2 to 10 minutes a day during the summer months, depending on the temperature.  
  3. Shelves and the roof get a dressing of slow release fertilizer and the wall and roof is watered weekly with a liquid fertilizer.  
    Figure 8. Living wall provides a backdrop to the deck beside the pond.