Mike asked "..Is there a parameter set to define size of garden?.."

Its all relative
If you had a garden of 5 acres and now have moved to half an acre then to
you have a small garden, if however you had a 20ft by 6ft garden then a move
to an eighths of an acre gives you a large garden.
I once had 2 Ladies in at the same time asking for rockery plants, both said
that their rockeries were "Quite large".
When pressed one said hers was 6ft long and about 3 ft deep, the other was
60ft long and went from 5ft to 14 ft in depth.
A small town garden will be a lot smaller than a small country garden.
Size is in the eye of the beholder.

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk