The Royal Horticultural Society (RHS) has recently been producing excellent single genus books. Known historically as botanical monographs, the works of the past twenty years give equal importance to horticulture. While the many species are considered for their habitats and qualities, so are the many selected varieties or developed cultivars that are important to gardeners. Illustrations are much more prominent than in older books, and include paintings by botanical artists, both contemporary and historical, and excellent photography.
Is this book useful if you are just looking for the most colorful and fragrant sweet peas? Yes – but there is much more, including how these plants exist within the complex biology of nature. The authors also remind us that our gardens are part of a much larger ecosystem.
“Lathyrus: The Complete Guide,” by Greg Kenicer and Roger Parsons, is primarily about sweet peas (Lathyrus odoratus), highlighting over 500 cultivars. Their development was especially rapid in the early 20th century, fueled by the introduction of the first Spencer type with its longer racemes (flower stalk) and larger, wavy petals. This led to “an explosion of interest in sweet peas during the Edwardian era.” It also began an era in which many of the breeders were amateurs. A contest for home growers conducted by the Daily Mail of London in 1911 brought in 39,000 entries.
This book takes the bold step of treating the garden pea, known in most sources as Pisum sativum, as part of this genus (as L. oleraceus) based on recent DNA studies. It also briefly reviews all 150 species in the genus, including L. vernus, an excellent early-spring perennial in Seattle gardens, and L. sativus, a widely grown fodder crop with deep blue flowers that “is a worthy annual ornamental in its own right.”
Excerpted from Brian Thompson’s article in the Spring 2023 issue of the Arboretum Bulletin