Plants, mankind’s greatest enemy, are finally on the ropes thanks to global warming. Teach your children how to hunt the last of these enormous nitrogen junkies by observing them in captivity with today's Groupon: for $10, you get two adult admissions to the Tower Hill Botanic Garden in Boylston (up to a $20 value). Children ages 6 to 18 are admitted to the garden for $5, and children younger than 6 enter for free.

Operated by the historic Worcester County Horticultural Society, the Tower Hill Botanic Garden offers 132 acres of lush gardens featuring Cary Award–winning plants and woodland trails to roll around in and cartwheel about. Bird and butterfly buffs can track the bewinged creatures' movements from The Wildlife Garden's human-size bird-viewing station, identifying species from the checklist. The gazebo overlooking The Wildlife Refuge Pond doubles as a platform to observe the marshy surroundings and a station for nature lovers to ponder the beauty of local fauna and whether or not they turned off their Large Hadron Collider when they left the house.

An 18th-century-style greenhouse called The Orangerie holds a variety of citrus trees, including dancy tangerines and persian limes. Those seeking a decidedly less tropical experience can walk along marked woodland trails or can behold the panoramic view of Mount Wachusett to the west.