Great tip Dinu. I use the black plastic nursery pots (one, two, three gallon size). The larger ones with the mold lines make excellent plant markers. Cut off top and bottom, then cut on the mold lines. China marker/grease pens last a couple of years on the black plastic.

Thanks Linda. In my opinion, anything can be used for this purpose. Just a little thought before throwing things will postpone them being thrown, hence slowing our undesirable contribution to our environment, while they continue to be in some use or other. We have reached a stage where we cannot totally avoid bringing in plastic as most items we buy come packed in such items.
Your pot idea is a good one. I do not know what those pens are.... any more tips on that count?