Wood for garden beds (Harrow HA1)

Hi all,

I would love some planks of wood for a 2 1mx1m garden beds, and suitable wood that can be made into posts (or, ‘posts’ if you have them already 🤷🏼‍♂️).
Close to HA1 as possible; extremely handy if you’re on 1 Bedford Road 😀

Thanks for looking.