Garden Pests

"He who helps destroy the boll-weevil has done as constructive work as he who plants the seed"
Rupert Hughes

Darker Side of Mistletoe

Mistletoe makes a welcome appearance as a decoration in homes around Christmas time, particularly in English speaking countries.

There are many traditions associated with this plant, but perhaps the best known is that of kissing under the mistletoe – a tradition believed to have originated in Scandinavia, where is was known as the plant of peace.

However, for the gardener, mistletoe has a darker side to its nature. For a start, some varieties are poisonous and can cause gastrointestinal problems diarrhoea and slow pulse. This plant also causes problems for the host trees in which it grows.

In many respects, mistletoe is similar to other plants with leaves and berries, but it differs from most in that it is parasitic.

It lives in the branches of trees and, instead of a conventional root system, it grows projections (haustoria) that are designed to penetrate the bark of the host tree from where the plant draws its supply of water, along with other nutrients it needs for growth.

In most cases, the host tree, suffering from the loss of water and nutrients, becomes weakened over a number of years. The branches that directly support the mistletoe are particularly vulnerable and often die.

Mistletoe relies on birds, such as robins and thrushes for propagation. The birds eat the berries and then deposit the seeds when they visit other trees. The seeds, being sticky, glue themselves to the bark and start off a new colony.