The Raulston is always fantastic, it tends to be more about woody plants and landscape vignettes than flowers though but I'm sure they'll have something in bloom, I also think they're having a guided tour on Sunday. I haven't been to Duke gardens in quite a while but it's all about the flowers, so that might be your best bet for flowering. The NC Botanical Garden is a fantastic place but it is more about conservation and native eco-systems than big, flowery displays. You could also check out their websites and social media to get an idea of what's going on at the various gardens.

I just saw this. We went to Duke Gardens on Saturday and it was quite beautiful. apart from the flowers, of which there were quite a few, the foliage was also beautiful. There was a wedding event and so a part of the heritage garden was off limits, but even then we enjoyed seeing the gardens. 3 or so weeks ago we had been to the Rose Garden at Little Theater in Raleigh and it was simply gorgeous.

You should definitely check out the Raulston some time, if you haven't already, especially if you're looking to do any landscaping at your home