How to Grow and Care for Mistletoe

More than 1,000 species of mistletoe are found growing worldwide. All of them are parasitic broadleaf evergreens. They attach themselves to the branches of other trees and shrubs and grow in loose twiggy balls via a root-like structure called a haustorium, which absorbs nutrients and moisture from the host plant. You should not grow mistletoe unless you need it for a festive holiday harvest. The mistletoe balls tend to look unsightly rather than ornamental, and their growth habits can be harmful, sometimes killing or seriously disfiguring trees. But if you are willing to keep the ball in check, mistletoe will provide you with a traditional decoration for the holiday season.

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 are toxic to people. Serious problems are possible for pets who consume large quantities of berries.

Mistletoe Care

If you decide to grow your own batch of mistletoe, you'll first need to have a healthy host tree of a species known to support mistletoe. American mistletoe prefers many hardwood species including oak, maple, aspen, ash, walnut, poplar, and elm. The tree needs to be well-established and should be at least twenty years old.

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.

Warning

Mistletoe species in the Arceuthobium genus, also known as dwarf mistletoes, are considered invasive in Canadian forests through western North America and south to Mexico and Central America. The foliage of these plants is very small and scale-like, and dwarf mistletoes can parasitize many plants, including large succulents. When a dwarf mistletoe appears in your landscape, immediately remove it because it is not suited to use in holiday décor.

Other species of mistletoe, though sometimes damaging and disfiguring to trees, are usually not considered invasive species.

Light

American mistletoe plants can cope with shady environments, but they do best in a full or partial sun location because they generate additional nutrients from the process of photosynthesis.

Water

This semi-parasitic plant receives its water from the host tree. No additional watering is required.

Temperature and Humidity

American mistletoe is a leafy variety that needs the temperate conditions of USDA cold hardiness zones 5 to 9 to survive. Regions that experience harsh, sub-freezing temperatures or exceptionally dry conditions are not suitable for growing this plant. In the wild, they tend to be found in low-lying areas that are fairly humid.

Fertilizer

Mistletoe requires no direct feeding because 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

At least 30 types of mistletoe are found in North America, some of them native, others are European or Asian species that have naturalized. Here are the most common:

• American mistletoe (Phoradendron leucarpum) is the most common species growing in North America. It is used for holiday décor—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. tomentosumssp.macrophyllum) is found in the Southwest United States from California to west Texas. It is also a popular plant for holiday décor.
• 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.

1. In late fall, harvest some mature ripe berries from an existing mistletoe clump on a tree.
2. Squash the berries into a pulp, then press them into the bark on the lower side of strong and healthy branch on a new host tree—ideally, the same species as the tree from which you harvested the berries.
3. Wait until spring, and check to see if small leaves are sprouting from the pulp. No watering or care is necessary; the mistletoe will draw all the nutrients and moisture it requires from the air and from the host tree.
   

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 forornamental holiday use—these berries are the product of female flowers. Mistletoe flowers in later winter or early spring, but the flowers are insignificant and are not worth encouraging.

If you want to harvest sprigs with berries for holiday décor, be patient—it can take as long as four years before a mistletoe plant is mature enough to flower and bloom. Most mature mistletoe will bloom readily provided they receive 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 from the host tree.

Common Problems With Mistletoe

The most common complaint about mistletoe is its unwanted presence. It often arrives uninvited, 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 herbicide to the mistletoe plant. Take care not to broadcast-spray herbicides, as they 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 re-sprout, and at this point can be carefully treated with herbicide to kill the plant.

From: thespruce