A Naughty (Not Nice) Story about Mistletoes

Mistletoes have long been associated with the charming holiday décor we hang above doorways to inspire kisses. And while they’re spreading joy indoors, mistletoes are creating…well…drama outdoors.

You see, to trees, mistletoes are less about romance and more about freeloading; that’s right. These are parasitic plants that live by syphoning nutrients from their unwilling host. It’s a classic case of a wolf in sheep’s clothing.

But don’t let this sour your holiday spirit. Read on to uncover the full story about mistletoes. We’ll also share tips on how to keep your trees safe from their not-so-nice tendencies.

What is Mistletoe?

Mistletoe are fascinating plants with a rather unique lifestyle, straddling the line between independence and dependence. Mistletoes in Western Canada are Dwarf Mistletoes and are classified as hemiparasites.

What does that mean? While mistletoes can perform photosynthesis to generate some of their own food, they prefer to live the parasitic dream. They’d rather draw water and nutrients directly from host trees using specialized root structures called haustoria.

The glossy green leaves and iconic white berries make mistletoes a symbol of holiday cheer, and they’ve enjoyed a starring role in folklore and mythology for centuries. Druids regarded them as sacred, Norse mythology tied them to love and peace, and today, we hang them in our homes to encourage festive smooches.

For trees, however, mistletoes are less about romance and more about trouble.

Once attached, mistletoes syphon resources, often weakening their host trees and leaving them more vulnerable to disease and damage.

While they hold charm as a holiday decoration, it’s important to understand that mistletoes can cause significant harm to trees if left unchecked. They're definitely more naughty than nice in the plant world!

Where Does Mistletoe Grow?

Mistletoes thrive in mild climates, favouring regions with just the right balance of sunlight and moisture. You’ll commonly find them in Europe, North America, and parts of Asia. In Canada, provinces like British Columbia and Alberta provide the perfect conditions for these opportunistic plants to flourish.

These parasitic squatters are particularly fond of sunny, open areas and high canopies, where they attach themselves to host trees and soak up all the sun they can get.

Mistletoes may look innocent with their glossy leaves and festive berries, but don’t be fooled. In small numbers, they might not seem like a big deal. However, when they spread unchecked, especially in densely forested or urban environments, they can cause significant harm to their host trees.

Their ability to spread far and wide, often aided by birds that feast on their berries and scatter the seeds makes mistletoe a sizable threat.

What Trees Does Mistletoe Grow On?

While mistletoe can affect many types of trees across different regions, the Dwarf Mistletoe is the only one present in the Prairies, and it has a preference for coniferous trees.

This parasitic plant primarily targets lodgepole pine and jack pine, both of which are common in the Prairie landscape. It can also sometimes affect black spruce and white spruce.

Are They Naughty or Nice?

Mistletoes are frenemies in the plant kingdom – helpful in some ways but harmful in many others.

The Nice Side

• Ecosystem Benefits: Mistletoes play an essential role in ecosystems, providing food and shelter for birds, insects, and mammals. Birds, in particular, feast on their berries and help spread seeds.
• Pollinator Paradise: Mistletoe flowers, though small, are a valuable nectar source for bees, butterflies, and other pollinators, especially during colder months when fewer plants are blooming
• Biodiversity Boosters: They create habitats for various species, contributing to ecological diversity.

The Naughty Side

• Tree Health Impact: By stealing water and nutrients, mistletoes weaken their host trees, sometimes leading to death in severe infestations.
• Stunted Growth: Host trees infested with mistletoe often exhibit reduced growth due to nutrient and water competition, leaving them less vibrant and weaker overall.
• Branch Damage: Infested branches are prone to breaking under stress, especially during winter storms.
• Spread of Disease: Weakened trees are more susceptible to secondary infections and pest infestations.

How to Control Mistletoe Growth

If mistletoe has taken up residence in your yard, it’s time to act. Here’s how to manage and prevent infestations:

• Preventive Measures: Conduct regular visual inspections of your trees, particularly during winter when mistletoe is easier to spot on bare branches. Remove small mistletoe infestations immediately to prevent them from spreading. Also, keep the area around your trees free of dropped mistletoe berries that could germinate on nearby hosts.
• Pruning: Cut infested branches at least 12–18 inches below the mistletoe’s attachment point, ensuring you remove all connected tissue. Leaving even a small part behind can lead to regrowth. Make sure you prune during the dormant season for better visibility and to minimize stress on the tree.
• Improve Tree Health: Water deeply during dry periods, fertilize trees with slow-release fertilizers, and apply about 4 inches of organic mulch around the base of trees. You can learn more about keeping your trees healthy here.
• Use Growth Regulators: Chemical treatments like ethephon can suppress mistletoe growth temporarily by causing it to dry out. These products are not a permanent solution and must be applied correctly to avoid harming the tree.
• Call in the Experts: For extensive infestations or large trees, enlist the help of ISA-certified arborists who can safely remove mistletoe and provide tailored advice for tree care. Arborists can assess the structural health of the tree and recommend long-term management strategies to minimize future infestations.

The Verdict: Mistletoes Are Naughty But Manageable

Mistletoes may add charm to your holiday decorations, but in the tree world, they’re more freeloaders than festive friends. By understanding their behaviour and taking proactive steps to manage infestations, you can protect your trees and enjoy a healthier yard.

Need help taking care of trees?

Green Drop’s professional tree health care services are here to help. From pruning to health assessments, we’ve got you covered in Red Deer, Winnipeg, Calgary, Edmonton, Regina, and Saskatoon.

So, go ahead and hang that mistletoe in your doorway – but make sure it stays there and away from your trees! Get a free assessment for your tree service.