Every backyard vegetable garden eventually grows more than one family can eat, and that extra is where the kindness starts. The hobby may keep gardeners sharp, too. A University of Edinburgh study that followed 467 older adults into their 90s found that people who gardened regularly had better thinking skills in later life, and the advantage held all the way from age 79 to 90. Here, $3 worth of pumpkin seeds fills empty porches on Halloween, a vegetable garden inheritance surprises the whole family, and a stranger starts tomato seedlings for a family she hasn’t even met. Planting for someone else turns out to be the surest way to grow happiness.