In Denmark, where I live, the supermarkets and Christmas markets are just beginning to sell bundles of European mistletoe (Viscum album), and no doubt across the pond, American mistletoe (Phoradendron leucarpum) is gracing the shelves, while down under in Australia, it could be any of 90 species.
Mistletoe isn’t just one plant, rather a collection of hundreds of species of hemiparasitic plants—those that parasitize for water and nutrients but can still photosynthesize—in the Santalaceae, Misodendraceae and Loranthaceae families. Bundles of these odd tree-dwelling shrubs have long been a staple Christmas decoration, marking a spot for a kiss. However, the tradition of hanging mistletoe in the house around the time of the winter solstice goes back at least as far as Iron Age druidic customs on the British Isles, and the enduring association of mistletoe with midwinter has followed Europeans around the globe.
While it may seem counter-intuitive to proliferate a parasite, recent ecological studies native mistletoes can be a boon for biodiversity. In Australia, for example, it was found that one-third of woodland-dependent bird species have some sort of attachment to the local mistletoe population, providing them fat-rich nectar and a safe, camouflaged haven for nesting.
Many of your holiday mistletoe bundles come with viable seeds encased in sticky white berries. The seeds—normally distributed by birds that wipe them off their beaks or bottoms onto a tree branch—are easy enough to work with. The sticky natural glue that surrounds them is called viscin, and you can grow your own bounty of mistletoe by adhering them onto a strong branch or crotch of a tree with a little push.
A mistletoe will take years to grow—the European species usually only grows one forked leaf section a year, so it’s not an enormous drain on the resources of a tree. Indeed, nurseries have begun selling trees that are already infected with mistletoe plants.
My local species here in Europe prefers to colonize trees like apples, rowans and other members of the botanical subtribe Malinae, but it will infect a variety of other trees. Other species will colonize other types of trees. Knowing which branch to place a mistletoe seed on is just a matter of doing a little research. A short investigation into your local mistletoe species—and their preferred hosts—can turn this seasonal decoration into a multi-year project, one which will benefit all sorts of creatures that share your biome.