Q. Where can I buy ornamental cherry trees in Rockland or Westchester County?
Thank you for your inquiry. I have heard of a nursery that carries trees, and can get particular types from their wholesalers in the trade, as most large scale nurseries can.
Rosedale Nurseries (51 Saw Mill River Road and Route 9A, Hawthorne; 914-769-1300) has a new shade-plant section, a vast collection of specimen shrubs, large trees, perennials and annuals, as well as ornaments, supplies and books.
Suggested by Arthur Linda Yang in an article by the NY Times https://www.nytimes.com/1994/05/12/garden/nurseries-for-every-gardener.html
Hope this helps.