One Year or a Thousand

This isn’t one of my usual posts with pretty photos of moths or hedgehogs. Instead I’ve got photos of bits of plastic decomposing, or not, in our garden. This may not be the most aesthetic post, but it does touch on something we should all be concerned about. We subscribe to a few groups who send us magazines and I am also partial to the occasional wildlife or the odd foodie magazine. Many of these publications arrive in single use plastic covers. With everything in the press and on our minds of late over the use of these plastics, I was particularly pleased, when a year ago, our magazine from the Butterfly Conservation charity arrived with the following note:

Our magazine was wrapped in a bag made from biodegradable or compostable potato starch. Why can’t all magazines come like this?

So maybe I need to get out more, but I thought it would be really interesting to see just how long it would take for this starch bag to decompose. I decided to put the potato starch bag outside and document its hopeful decay. Old lab habits die hard though and I felt the need for a “control” subject, so fished a real plastic magazine bag out of the bin and placed it next to the starch bag for comparison. So here we have on the left a traditional plastic bag and on the right the compostable starch bag from Butterfly Conservation.

I laid them side by side on the patio, weighted down with stones. Of course the starch bag should really have gone in the compost bin to degrade quicker, but then I wouldn’t have been able to monitor it. This way I could compare how the starch bag changed while the plastic magazine bag remained the same.

Initially I was a bit over-optimistic and planned to photograph the bags every week, expecting rapid change. Clearly these things take longer, especially when just sitting on a concrete patio! So after 3 weeks there wasn’t much change, apart from various bits of crud having landed on the bags.

By May this year though there were the first signs of decomposition of the starch bag in the top right corner.

By September, the starch bag was really starting to break down, whereas the plastic bag on the left looked pretty much the same.

By November, a year since I put the 2 bags out, the starch bag has almost completely disintegrated. The plastic bag on the left looks pretty much the same as it did when I laid them down originally. Cleaned up the plastic bag on the left would still be very much recognisable, the starch bag on the right is barely there.

They say a regular plastic bag takes anywhere between 10 and 1000 years to decompose (depending presumably on which “they” did the research). The thought that a plastic bag that was used solely to cover a magazine that we read once, then discarded, could still be here any time up to 1000 years from now, is fairly horrifying. If Butterfly Conservation can distribute their magazines in biodegradable starch bags, surely there can be no excuse for any other magazine not to be doing the same?