As every Road Trips Gardener knows, the Chelsea Flower Show is the big one — the one every gardener should visit at least once.

This year’s edition, held on the grounds of the Royal Hospital Chelsea, London, England, United Kingdom, is May 24 through 28, 2011.

Visitors will see the show gardens, inspirational small gardens and vibrant horticultural displays that make up the world’s most famous flower show.

It’s sponsored by the Royal Horticultural Society. Tickets are available online. Tickets must be purchased in advance, and some timeslots are already sold out. So, if you’re planning to head across the pond to check this show off your bucket list, buy a ticket to the show before you buy your plane tickets.

(Photo courtesy of the Royal Horticultural Society)