Perennials, a 3-page pdf from CCE of Suffolk County, includes information on soil preparation, propagation, receommendations on easy-dare perennials, and recommended publications.
Perennial flower trials at Cornell University - photos and data on hundreds of perennial varieties from the test plots at Bluegrass Lane
Dividing Perennials is a 5-page handout from CCE-Chemung Cooperative Extension that covers how and why to divide some common perennials.
Cornell Horticulture offers an illustrated list of their top 15 perennial-and-bulb combinations on their website at: http://www.hort.cornell.edu/combos/FeaturedCombos/Best15Combos/
Perry's Perennial Pages offers on-line perennial and related horticultural information on a centralized database.
Last updated December 13, 2016