Garden planner software - preferably free

[AMumInScotland]

So, we came back from Monet's garden at Giverney full of plans to make our garden lovely and full of colour... First step, I thought, would be to get a proper plan of what is where at the moment and then use that as the basis for plotting out different ideas, with beds and paths and stuff.

So, I'd like to use some garden planner software to do that.

I've tried the BBC Virtual Garden one this evening, but it doesn't seem to have any option to mark out different areas - at least, you can, but you don't get any idea of the measurements, so what's the point of that?

Has anyone tried any package for this, that they could recommend (or tell me to avoid at all costs)

TIA