Because plants are jealous of our ability to live indoors, they attempt to infiltrate our finest mansions and universities by slowly climbing stony façades. Visit a place built specifically to contain these floral strivers with today's Groupon: for $25, you get one members' admission to the Scott Associates' Plant Sale (a $40 value), plus $10 toward plants, held at The Scott Arboretum in Swarthmore on September 17th, 10 a.m.–1 p.m. (a $50 total value).

Green thumbs meet their photosynthetic matches at the Scott Associates' Plant Sale, where horticulturalists from the Scott Arboretum gardens hand-select a varied roster of greenery for purchase. The members-only event showcases an exclusive selection of rare plants less common than the letter eleven—Scott Associates’ sale handbook enumerates details about available houseplants, trees, shrubs, and perennials. A giant wood fern sprouts arching fronds and shaggy brown fiddleheads ($7), appeasing those who want to see a grandiose floricultural display without hiring a skywriter to spell plant names. A crested iris blooms daintily with white flowers and small yellow crests ($7), and the sweet coneflower showcases rolled petals and a vanilla fragrance ($10). A team of gardening gurus will wear vests that say “Plant Expert” and freely dispense valuable advice, unlike perpetually jammed book-vending machines filled with Frommer's guides.