Robert is at the garden as early as is feasible, possibly organizing whatever there is to organize or otherwise looking like he's engrossed in doing something... horticultural. He is making a distinct point of staying at the sidelines, avoiding the general crowd except for those he knows well or those who approach, but he isn't giving off a go-away-esque vibe, either - he simply seems nervous, as is usual for him in these sorts of situations.

He might be able to be coaxed to do something less professional, though, like have a nice chat.

And maybe, if there's a lull in the crowd, one might catch him planting a few flowers of his own. They all seem very carefully picked for symbolic purposes, and Robert handles them with a delicacy seeming odd for even flowers. He can certainly be interrupted at these points, too.