Gardners in Spitalfields on a sunny Saturday

149 Commercial Street

This shop, just along from Spitalfields Market, always brings a smile to my face. And especially so on such a gloriously sunny day. It's a joy to know this family business is still trading after all these years – 148 years to be precise.
But where to place the apostrophe in the name? Is there one at all?
In the pic you can see they've placed it before the S as in the shop or business of Mr Gardner.
But having just checked their website I am now confused – on the home page it's visible as Gardners (plural, no possession) and, within the central graphic on there, it's depicted as Gardners' (plural possessive).