useful 2 litre clear plastic containers
I have found plastic bottles such as those used for bottled water very useful on my allotment. I cut them in half and use both pieces to protect young plants when planting them on the plot.
They protect the plants from birds and slugs and act as mini cloches to protect from frost and ease the transition from the cold frame to the open ground. I keep a stock of them and use one half bottle on each plant, earthing up soil around their base to make them stable against wind. They are also reusable and can be kept for use over several years.
If you cut them in half lengthways they also can be used as mini cloches to protect newly sown seed rows in the nursery bed.
The best bit is, if you buy bottled water anyway, the containers are free.