How long will these take to breakdown?

Now that runner bean plants are being pulled up and composted it may be time to look at how these  and other plants that are tied to supporting poles can contribute to plastic waste  in the compost.

Plastic string is often used to tie the bean plants and it would be relatively easy to cut and remove the strings before pulling the plants down and putting them in the compost bin.  However,  it would appear to be easier to leave the string round the plants so that the plastic ends up in the compost bin. The photo shows the crop of string from just one of our reception bins today and it is worth noting that the beans formed a relatively small proportion of the waste in the bin.

Although marine pollution by plastics has received more publicity  terrestrial microplastic pollution is 4-23 times higher  than marine pollution  depending on the environment. Perhaps as gardeners we should pay more concern to our use and disposal of plastics

The Guardian report I mentioned recently on microplastics can be found at: https://www.theguardian.com/environment/2020/sep/02/microplastic-pollution-devastating-soil-species-study-finds