Q. what is the cultivar name of the beautiful red red mandevilla climbing in the courtyard containers near the entrance?
Hello Arabella S. Dane,
The Mandevilla plant may be Mandevilla 'Sunmanderemi' [sold as Sun Parasol Pretty Crimson®] according to our records ; usually kept in our NYBG Nolen greenhouse. Although, red, pink, or rarely white varieties are commonly available at retail nurseries. An easy care plant but must be overwintered indoors in a bright cool spot. Let me know if you need more information.
Hope this helps.