WHAT: “Great Gardens of the Philadelphia Region,” a new exhibit at Penn’s Morris Arboretum featuring the work of Ambler-based garden photographer Rob Cardillo.

WHERE: The Morris Arboretum is located at 100 Northwestern Avenue in Philadelphia’s Chestnut Hill section. The exhibit is on display in the Upper Gallery of the Widener Visitor Center.

WHY: The exhibit showcases some of the most beautiful gardens in the Philadelphia region. According to Cardillo, that’s saying quite a bit. Cardillo took the photos while researching his soon-to-be released book, “A Guide to the Great Gardens of the Philadelphia Region,” which he co-authored with Adam Levine. And now that’s he’s finished, Cardillo says he is more convinced than ever that Philadelphia is a true gardening mecca. “We actually call Philadelphia the epicenter of horticulture in the United States,” Cardillo says. “We really felt that way after doing this book, just because of the great number and variety of public gardens here.”

A LOVE FOR GARDENING: “I’ve been shooting gardens and horticultural subjects and gardens for the past 20 years,” says Cardillo, formerly a staff photographer for Organic Gardening. “I have a lifelong love of plants and gardening, and a lifelong interest in photography. It’s a nice niche to be in.”

WHITTLING DOWN: Cardillo photographed more than 200 gardens while researching his book, but had to choose just 25 for the Arboretum exhibit. “I wanted to make sure the exhibit was representative of the book,” he says. “I wanted to make sure, as much as possible, that we had a fair representation of the different gardens we saw. It was a little difficult, though. I have my favorites, of course, but it’s really hard to say which would be my one favorite.”

WE’RE NOT LETTING YOU OFF THAT EASY: “Well, Chanticleer is always full of surprises, so that’s one of my favorite gardens. And the community gardens are delightful. There’s such a spirit in the people there, and there are some that I’d never been to before—some of which I hadn’t even considered gardens.”

SUCH AS?: West Laurel Hill Cemetery in Bala Cynwyd. “It was full of some really amazing mature trees and landscaping, which were really striking when set against the marble headstones.”

THE DETAILS: The exhibit is open daily from 10 a.m. to 4 p.m., through May 13. Admission to the exhibit is free with Arboretum admission. On March 18 at 2 p.m., Cardillo and Levine will host a lecture and book-signing Reservations for the event are required. For more information, call 215-247-5777 or go to www.morrisarboretum.org.