Some locales organize tours of private gardens every spring, giving visitors a peek inside historic and often well-appointed homes that are not otherwise open to the public. Newport, R.I., hosts a "Secret Garden Tour," June 15-17. Natchez, Miss., has a "Symphony of Gardens Tour" May 4-5. Atlanta's Gardens for Connoisseurs Tour, May 12-13, is a fundraiser for the Atlanta Botanical Garden. Historic Garden Week in Virginia, April 21-28, sponsored by the Garden Club of Virginia, features 30 tours around the state, from 18th century James River plantations to walled urban retreats.

Most visitors to botanical gardens are day-trippers, but you can also plan a vacation around far-flung gardens. Elderhostel, a tour company that specializes in educational travel for older adults — www.elderhostel.org or 800-454-5768 — offers trips to gardens in destinations ranging from Southern cities and the West Coast to England and New Zealand.

Adam Hurtubise, Elderhostel spokesman, says the number of garden programs offered by the company, along with enrollment, is on the rise. Also popular, he says, are Elderhostel programs with a service component, where participants can get their hands dirty and work on historic gardens in addition to taking a tour. One such Elderhostel program includes an option to work on the Victorian garden at the Emlen Physick Estate in Cape May, N.J.

Listed in the sidebar are a few garden tours from around the country. Call ahead for reservations, fees and visiting hours, which often change with the seasons. Ask about customized group tours, which are available at many botanical gardens.