Spring! Free and discount Botanical Gardens!

Brooklyn Botanic garden is free Tuesdays, and Sat till noon.
Bronx Botanical garden is free on Wednesdays (grounds only)
Cloisters is always PWYC - Fort Tryon and the Heather Gardens are free
Snug Harbour, Staten Island, always free
New York Conservatory Garden, at the top of Central Park, is always free.