Purchase wooden pegs so that when they break they can be either composted or burnt. 

Available from Go Bamboo, or those rustic minimal homeware stores always seem to have them.

We haven’t had the problem, but if you find the pegs leave marks on your clothes, then place the pegs in a saucepan of cold water and then bring it to the boil. This makes the tannins leach out. Also keep wooden pegs out of the weather.