Bring a taste of the outdoors into your house by planting a houseplant! This is a holiday that proves you don't need a backyard to enjoy the benefits of having plants in your life. There are tons of studies that prove keeping plants in your house can help improve your mental health, so get planting! This holiday was started by The Gardener's Network to encourage people to keep indoor plants during the cold winter months. So take that Christmas tree down and put some new plants up!