Before sending a story to copy editing, the editor should verify all plant names. Lead copy editors may check plant names at their discretion at manuscript stage and should check all plant names at first proof stage. Subsequent copy editors and proofreaders need to look up only names that seem questionable or plants that are added at later stages.
The first source for spellings and plant details, including Zones, is BHG.com Plant Encyclopedia. Additional reliable plant name resources include the Missouri Botanical Garden plant finder and USDA plants database. A good source for common names is A–Z Encyclopedia of Garden Plants, which lists plants by scientific name (genus, then species, then cultivars [in single quotes]); common names are listed in parentheses and in an alphabetical index in the back of the book. There also is a plant word list in this stylebook for exceptions or preferences when there are several spelling options. (clarified 12.11.19)
If a plant name or details can’t be verified, the CE should note that on the layout so the editor can double-check in another reference. Do not change a plant name without checking with the editor, except in the case of an obvious typographical error.
Note: Be aware that, in some cases, more than one species might share the same common name. Specific plants also may have multiple common names. Defer to the editor’s choice in those cases.