Why Weed the Green Roof?

 

Weeds blocking access to the composter.  Planter waiting for a spot.

I had this question, recently, and figured others were likely wondering the same thing!

A green roof is not a wild roof because there are structural issues.  Seeds travel on the wind and by bird poop.  As much as we would love to see milkweed for the monarch butterflies and a small tree for birds, the roof cannot support the weight or the invasiveness of the roots. 

A green roof has a variety of plants that are sturdy, drought resistant and have really shallow roots.  Deep roots could break through the roof membrane.  If that happens, there will be all kinds of structural issues with water getting where it is not supposed to go.

There is a contractor for our building who only takes care of the section of the green roof that we don’t have access to.  The original contractor was responsible for the entire green roof.  Now, as with all other CCOC rooftop gardens, the Metcalfe gardeners receive a plot in exchange for keeping our section of the roof weeded and clean. 

Weeds behind planters with a planter nobody in the community garden on the ground wanted.  Apparently, the roof won't handle the weight of the planter in the winter, yet it sits there looking like garbage.  By managing our green space, maybe we won't become the dumping ground. 

At the meeting on Sunday 23 June 2015, the Metcalfe gardeners recognized that there were many deep rooted weeds and that the roof looked unkempt as opposed to wild.  

Patio tiles with weeds growing.  Eventually, Mother Nature will crack our tiles and the roof will look even more unkempt.  We have a new tool to make weeding this easy, though!

Our rooftop has the potential of being a beautiful, organic, food secure habitat for pollinators and people, while lowering the carbon footprint of the community below the roof.   We also want it to be easy to maintain. 

We came up with a concept, with the view to filling in the details in the near future.   The group decided which plants we definitely wanted to keep.  Evelyn was supported in wanting a section to be for wild, native plants.  Overwhelmingly, the group wanted to add plants that were either edible or valuable food sources for pollinators.  The CCOC Garden Facilitator let us know that the roof was not toxic for growing food, but that it is not nutrient rich; this will be a challenge in selecting plants that will thrive.

Michael and Robert were the first to start weeding (14 hours in a small area);  they found one section with ridiculously invasive roots.  It became evident that the plan to get rid of almost everything and start again was a sound decision. 

Over the next couple of weeks, while we are weeding, ideas will flow.  At the next meeting, we will zero in on which plants we want and then figure out how to get them.  Those who can’t make the meeting – it is summer vacation time – are encouraged to send suggestions via the rooftop coordinator. 

We weed the roof to make our home lovely and safe.