University of Vermont Extension 
Department of Plant and Soil Science

Growing Perennials in Cold Climates
Mike Heger and John Whitman.  1998.  Contemporary Books, 430 pp, hardcover.

If I were just teaching perennials, this would be a top candidate for an all-purpose text, especially for perennials in northern gardens.  It basically has two parts-- the first being over 5 dozen top perennial genera, including 1,700 cultivars or varieties; and the second part on the basics of growing perennials.

For each genus in the first part, a color photo is given, and a summary including bloom time, expected longevity (not seen in many books), degree of maintenance (another useful rating not often seen), years to bloom, and preferred light.  The latter again is quite realistic, taking into account the fact that many plants will grow in other light conditions just not as well.

Following this summary is a bit of introduction about each genus, then how it grows, where to plant, companion plants to combine and use effectively with it, planting, care, problems, propagation, special uses, and some sources.  Care is often a big question for gardeners, and the authors include such as water, mulch, fertilizing, weeding, staking, deadheading, and winter protection.  Then there is a quite useful table for each genus of key cultivars, listed by species, with key traits such as color, height and hardiness.

The second part of the book on basics of growing, begins with understanding and buying perennials.  Following are chapters on selecting and preparing the site, planting, care, solving problems, propagating, and special uses such as cut flowers and perennials as food.  The final chapter is on tools and supplies, useful as a checklist, gift list, or reminder of how to use various ones.

The authors are unique to many garden writers, in both having careers and experience as professional growers.  Mike Heger is co-owner of Ambergate Gardens in Minnesota.  Each year he sells over 2000 different kinds of perennials hardy in the north.  Prior to this, he spent 15 years gaining experience at the Minnesota Landscape Arboretum. He has been quite active in the industry's Perennial Plant Association, and is also active in many other plant societies.

John Whitman is a garden writer and photographer, has written other books and articles, has been gardening in the north for over 40 years, and spent years as a grower at Bachman's in Minnesota-- the largest retail florist and nursery in the United States.