Mark,
I'm not particularly fond of South Florida, certainly not compared to the in season flora and fauna of the northeast US or the countryside of the UK.
That said, I remember spending some very nice afternoons around Doral amidst the large ficus trees, Palm trees,blooming plantings and yes even the lakes.Lots of great times fishing with my kids.
So yes, I would say it can be quite beautiful in March, especially as they hit the height of their "spring", and especially if one is coming out of a nasty northern climate for a few days.