16-24″ tall x 18-24″ wide. The large, showy, fall-blooming Aster novi-belgii ‘Professor Kippenberg’ (New York Aster) is a fantastic plant that blooms reliably in late summer/early fall with clouds of blue flowers on tall, self-supporting stems. This is an essential late-season source of nectar for our treasured butterfly and bee pollinators! Native.