How to get rid of mistletoe?

How to recognise mistletoe?

Easily recognisable by its rounded habit, mistletoe stands out clearly in the tree canopy once autumn arrives. Its leaves are thick, evergreen, grouped in pairs and have no peduncles. Its flowers are small and inconspicuous and appear from March to May. They are pollinated by insects.

Whitish translucent berries then appear and are the simplest criterion for identification. This plant always grows on a host and is never rooted in soil.

Mistletoe, a botany plate, and berries clearly recognisable on the right

Mistletoe: care guide

Mistletoe (Viscum album) is an epiphytic undershrub. This means it absolutely needs a support to be able to germinate and develop.

Unlike ivy or tropical orchids, mistletoe does not simply cling to the tree: it penetrates the host with a root (called a haustorium) to extract some of the crude sap as well as water, which is all the more problematic with our increasingly dry, hot summers! Mistletoe is nonetheless capable of carrying out photosynthesis thanks to its small fleshy leaves. That is why it is described as hemiparasitic.

Where does mistletoe grow?

Mistletoe attacks a wide variety of trees: primarily poplars, apple trees, lime trees, rowans, whitebeams, willows, black locust, hawthorns, … Moreover, it will rarely (if ever) attack your pear trees, cherry trees, hazel or chestnut trees.

Once mistletoe is established on a tree, it can live up to 35 years and reach a diameter of one metre if nothing is done to control it. Mistletoe nevertheless grows very slowly. It tends to establish on weakened or stressed specimens (droughts, wounds, soil impoverishment, old age, diseases…).

Here is an apple tree badly attacked by mistletoe… (Photo: Jeppestown)

How does mistletoe spread?

Its small whitish berries are much favoured by birds (particularly thrushes), which ensure dissemination of its seeds. These are expelled with the birds’ droppings onto the branches of trees, stick there and germinate. This perennial plant particularly appreciates moist valley bottoms. It tends to settle on horizontal branches or in forks because moisture is more likely to linger there, which facilitates seed germination.

Note: Beyond the damage caused in orchards, mistletoe is also feared by foresters because it causes deformities and devalues wood. This is known as mistletoe-affected wood.

When to intervene?

It is important to remove mistletoe as soon as it appears! On trees already hosting mistletoe, remove it in winter, when trees are in dormancy.

How to remove mistletoe from trees?

Equipment needed :

To eliminate mistletoe on your trees, you will need :

• a saw, loppers or a sickle (depending on age of mistletoe and section of branch to cut)
• a ladder
• a knife
• a healing balm
• a pair of gloves

How to remove mistletoe ?

There are not dozens of methods to eliminate it: mistletoe must be pruned. Pruning is the most effective way to get rid of this plant.

1. Place ladder in tree to reach parasitic organism ;
2. Cut all mistletoe: prune as close as possible to base of the branch to which it is attached ;
3. Then use a knife to dig out the sucking root that has worked its way into the branch itself. If you skip this operation, mistletoe will very likely produce new shoots from the spared root the following year ;
4. Apply a healing balm to prevent disease (facultative), some gardeners simply recommend leaving the wound to breathe.

François’s tip : check at least every two years that mistletoe is not producing new shoots where you intervened !

Preventive measures

People often ask : Does mistletoe kill trees ? Mistletoe tends to establish itself in ageing, poorly maintained orchards. A single mistletoe plant is not a disaster in itself for the tree but when several plants attack your apple tree at the same time, it will eventually decline and die within a few years.

The earlier mistletoe is spotted, the more damage and seed dispersal we will limit. Indeed, the fewer berries it produces, the less it can be spread by birds to surrounding trees. Preventing it from flowering and therefore producing seeds is the best way to limit its spread.

François’s tip : Ensuring overall good health of your apple trees within the orchard is also a good control method. A supply of complete organic fertiliser and/or well-rotted compost can help ensure vigour and productivity of your trees. Appropriate and regular pruning will also improve air circulation within your apple tree and prevent moisture stagnation. Finally, I recommend brushing off moss from horizontal branches with a soft brush to counter mistletoe germination.