The best plants are fiercely loyal, brightening up our bad days or warning us of impending breakups. Add to a prescient vine collection with today's Groupon: for $20, you get $40 worth of plants, flowers, and garden supplies at Mahoney's Garden Center. This Groupon is valid at all eight locations: Brighton, Chelmsford, Concord, East Falmouth, Osterville, Tewksbury, Wayland, and Winchester. This Groupon expires on August 31.

Mahoney's Garden Center beckons green-thumbs and novices alike to its sprawling facilities, which burst with a plethora of plants, blooms, and gardening accoutrements. Although merchandise varies by store, shoppers may score finds such as a knock-out rose shrub ($29.98), zinnia perennials ($4.98) or an 8-inch hanging ivy ($16.98), complete with a Rhodes Scholar application. The 6-inch hibiscus ($12.98) lends its vibrantly hued blooms to front porches or a modest giant's windowsill. Perch deserving bouquets in the 12-inch embossed teal ceramic planter ($44.99) or display 10- and 11-inch hanging baskets ($12.50) that double as hideaways for spare doghouse keys. Customers can also narrow their searches for outdoor patio furniture at the Winchester and Falmouth locations.