This 4 page fact sheet (FS-20) was originally published by the Northeast Regional Agricultural Engineering Service (NRAES, later known as the Natural Resource, Agriculture, and Engineering Service), a multi-university program in the Northeast US disbanded in 2011. Plant and Life Sciences Publishing (PALS) was subsequently formed to manage the NRAES catalog. Ceasing operations in 2018, PALS was a program of the Department of Horticulture in the College of Agriculture and Life Sciences (CALS) at Cornell University. PALS assisted university faculty in publishing, marketing and distributing books for small farmers, gardeners, land owners, workshops, college courses, and consumers