The Fungus That Wants to Ruin Christmas

By Heather Walton, VCE Program Assistant

Lophodermium needlecast

Lophodermium needlecast on Scotch pines

For some people, ringing in the New Year means taking down the beloved Christmas tree. There are a great number of families, like my own, who prefer getting real evergreen trees for their holiday decor. But, what many people don’t know is the amount of work put into growing and protecting these iconic holiday symbols, and some of the problems these plantations face.

As we are all aware, evergreen trees are known for keeping their pines year-round, and do not go dormant in the winter. So, what does it mean when suddenly a conifer or cypress goes brown? A possible answer: fungus. There are several fungi pathogens that cause needle drop and even premature death for many varieties of evergreen. But the main culprit we’ll be focusing on, threatens our wonderful Christmas trees.

According to “Diseases of Trees and Shrubs” the fungus pathogen we need to watch out for is Lophodermium seditiosum Needle Casts (Sinclair, et al.). This fungus affects Christmas tree plantations- especially if that plantation contains Scotch, Austrian, or Red pines- and can cause the most damage.

LophodermiumAs a fungus, it travels through spores, and typically contaminates the tree by infecting wet needles of branches at least a year old. It then colonizes within the needles, and causes premature senescence and casting. This basically means that the spores irreversibly stunt or arrest the growth of the needles and branches of the tree.

So how do we know if this is what ails our trees? And most importantly, how do we treat them? According to Penn State Extension, “The most accurate and easiest identification period for Lophodermium needle cast is in mid- to late summer when the fruiting bodies are present on needles infected the previous year. The shiny, black, football-shap