Should you want to plant a mistletoe, the best strategy is to find berries from an existing plant and carefully mash them into the bark of a suitable tree in late fall or early winter. Most species of mistletoe have a moderate to slow growth rate and will take some time to achieve maturity. Mistletoe can be moderately toxic to people, causing intestinal distress if berries are consumed in quantity. The berries are more seriously toxic to pets. Serious problems, including death, are possible for pets who consume large quantities of berries. When mature berries are forced into bark cracks on the underside of well-established branches, they may germinate and develop into active mistletoe plants that will provide leaves and berries for holiday use. Be aware, though, that the mistletoe will derive its moisture and nutrients from the host tree and thus may diminish its strength. Thus, mistletoe is best suited for a large, healthy tree. Once established, these parasitic plants will require some regular pruning to keep the heavy balls from damaging limbs on the host tree.
Light
American mistletoe plants can cope with shady environments, but they do best in a sunny or semi-shade position. This is because they gain additional nutrition from the process of photosynthesis. Other species of mistletoe, though sometimes damaging and disfiguring to trees, are usually not considered invasive species.
Water
This semiparasitic plant gains its water from the host tree. No additional watering will be required.
Temperature and Humidity
American mistletoe is a leafy variety that needs the temperate conditions of USDA zones 5 to 9 to survive. Regions that experience harsh, sub-freezing temperatures or exceptionally dry conditions are not going to be suitable for growing this plant. In the wild, they tend to be found in low-lying ground zones that are fairly humid.
Fertilizer
Mistletoe requires no direct feeding, as it derives its nutrients from its host plant. But it’s advisable to keep the host tree or shrub well fed in order to maintain its health as it supports the parasitic mistletoe.
Types of Mistletoe
There are at least 30 types of mistletoe found in North America, some of them native, others are European or Asian species that have naturalized. These are the most common:
American mistletoe (Phoradendron leucarpum) is the most common species growing in North America. It is used for holiday decor—though normally harvested in the wild rather than deliberately planted in residential landscapes.European mistletoe (Viscum alum) is the traditional holiday mistletoe. It has naturalized in some areas of North America but is more prevalent in Europe and Asia.Big leaf mistletoe (P. tomentosum ssp. macrophyllum) is found in the Southwest United States, from California to west Texas. It is also a popular plant for holiday decor use.Dwarf mistletoe (Arceuthobium spp.) is the type regarded as invasive in much of North America. There are several different species of dwarf mistletoe native to different areas of North America, each with favorite host trees.
Pruning
As the haustorium establishes and grows, the mistletoe will start to develop into a ball shape and has been known to reach in excess of 100 pounds in weight and be up to 3 feet in width. Pruning back mistletoe balls will help to ensure they do not become too heavy for the branches of the trees they are inhabiting. If an unwanted mistletoe ball appears on a tree in your landscape, you will have to cut it right back to the base and then cover the remainders with black plastic to kill it off permanently. Herbicides applied directly to new growth are also useful for eradicating an unwanted mistletoe plant.
Propagating Mistletoe Plants
Mistletoe propagation can be tricky. You need the right conditions and a suitable tree host.
Common Pests & Plant Diseases
Mistletoe is not subject to any serious pest or disease problems, as befits a plant that is often considered an undesirable weed.
How to Get Mistletoe to Bloom
The only reason to encourage a mistletoe to bloom is if you want the whitish berries for ornamental holiday use—these berries are the product of female flowers. Mistletoe does flower in later winter or early spring, but the flowers are insignificant and not worth encouraging. If you do want to harvest sprigs with berries for holiday decor, be patient—it can take as much a four years before a mistletoe plant is mature enough to flower and bloom. Most mature mistletoe will bloom readily provided they get plenty of sunlight. If you notice a mistletoe plant blooming, simply wait for the berries to develop. They will ripen and remain on the plant until it’s time to harvest them in the early winter—it will be easier to spot the clumps once the leaves have fallen on the host tree.
Common Problems With Mistletoe
The most common complaint about mistletoe is its unwanted presence. It often arrives unbidden, usually sown by birds who spread the seeds through droppings after eating the berries. If a landscape tree develops a ball of mistletoe growth, it’s usually easy enough to prune it away, though with a tall mature tree, this is best left to a professional with climbing gear. On smaller host trees or shrubs, you can do the work yourself, either by regular pruning of the mistletoe ball or by careful application of an ethephon herbicide to the mistletoe plant. Take care not to broadcast-spray herbicide, as it could potentially damage the host plant. Simple removal of the surface growth usually leaves portions of the rootlike haustoria extending under the bark and into the vascular tissue of the tree. The mistletoe plant will often resprout, and at this point can be carefully treated with herbicide to kill the plant permanently.
