Last-minute travel can be fun and sometimes a bargain, but some events require booking far in advance. For example: the Chelsea Flower Show, held each spring in London. Insight Vacations is already taking reservations for the 2017 version of its European Affair with the Chelsea Flower Show tour and expects it to sell out fast. The nine-day trip begins in late May in London and includes a day devoted to the show. Moving on to the Netherlands, a highlight is a visit to the Aalsmeer Flower Auction, the world's largest. Then it's on to Belgium and Paris. Cost is from $3,365 per person, double occupancy, which includes eight nights' lodging, some meals and touring by motor coach. International air travel is extra. tinyurl.com/z4w3cyt