[starry]

I have about 4 lengths of black plastic tubing approx 5ft long and 3" diameter (they are old fishing rod holders) they are in my shed which I am currently sorting out I am loathed to throw them away as I know as soon as I do I will find a use for them  so any reasonable suggestions would be gratefully received thank you 

[noshed]

Keeping bamboo canes in?
Making a comfrey liquid container?

[Auntiemogs]

Cut into different lengths for stepped strawberry/herb planters (if watering is a concern you could always put a thin 'wick' of capillary matting in and stand them all in a large tray)? 

[Plot 6B]

A couple of suggestions...................
Use them to grow 'Show Standard' Carrots or Parsnips,
Or use them as part of an underground irrigation system.