With respect to the plants reviewed in this book and the author s recommendations on plant culture we will generally be considering plant culture in climates north of the midtemperatures between the Gulf of Mexico and Canada. This does not refer to a straight line east to west across mid-America since temperatures change with elevations. Although I have never gardened in Canada I assume this would include the southern areas of our northern neighbor as well as southern areas in the United States which have higher elevations. As a precaution I wish to remind people that various plants may be poisonous to taste and for some people to touch so children in particular should be cautioned.