Louise Bremner wrote:

You could take one of the photos to a garden shop, claiming you took it
while out for a walk in the neighbourhood and want to buy a similar
shrub for your garden. Make some excuse to abandon the quest after
learning the name of it but before actually buying it....

Louise, that is nearly as cunning as a cunning fox who is professor of
cunning at some Oxbridge dump. Except that in this town everybody knows
everybody. If I do manage to take a photo that doesn't completely suck,
I'll take it to a nursery and say what I said in the original post.
Can't manage that until I have a day off work though (May 21st...)