A leading allergist from the Surrey Allergy Clinic, Dr. Adrian Morris, emphasizes careful inspection of a Christmas tree before purchase. His guidance, reported by a major publication, is that mold lurking on real trees can trigger allergic reactions. He also warns that artificial trees should not be stored in humid conditions, where dampness can foster mold growth and degrade indoor air quality. These cautions are particularly relevant for households in Canada and the United States where winter indoor spaces are often kept warm and closed for extended periods.
Experts note that a real Christmas tree can harbor a significant amount of mold. In some cases, up to 50 different mold types may be found on the trunk and branches. Spores tend to multiply rapidly in cold, damp storage rooms, a common setup in small lots or garages awaiting sale. Once the tree is brought into a warmer living space, mold growth can accelerate as the higher humidity and warmth create ideal conditions for fungal expansion. While many mold strains pose little risk to healthy individuals, aggressive species such as Aspergillus, Penicillium, and Cladosporium can release mycotoxins or provoke strong allergic reactions and asthma symptoms in sensitive people. The risk is especially pronounced for those with asthma or known mold sensitivities.
Inhalation of mold spores can introduce irritants into the nose, throat, and lungs, leading to irritation, coughing, wheeze, or congestion. Some individuals may also experience sneezing, runny noses, or itchy, watery eyes after exposure. The symptoms can vary based on one’s overall health, the level of indoor ventilation, and the amount of mold present on the tree and in surrounding air.
To minimize exposure, Morris advises a careful wood inspection before purchasing and thorough cleaning of the tree once it is inside the home. A solution like mild bleach can help reduce surface mold, followed by thorough drying to remove residual moisture. Placing the tree in a well ventilated, spacious room improves air exchange and lowers humidity around the ornament. For households seeking a hypoallergenic option, opting for a plastic Christmas tree is a practical alternative. If a synthetic tree is chosen, it should still be kept in a dry, well ventilated location to prevent mold from forming in the storage area and inside the house after setup. Regularly rotating indoor spaces and using dehumidifiers during the holiday season can further reduce indoor mold risks.
Historically, some suggestions have included air-purification strategies using various materials. While these ideas originate from broader air quality discussions, the core message remains simple: control moisture, ensure ventilation, and choose a tree that aligns with household health needs and sensitivities. The practical takeaway is clear—whether real or artificial, proper storage and careful setup are essential to maintain indoor air comfort during the holidays. At the end of the day, informed choices and proactive maintenance help families celebrate with less worry about mold-related allergic reactions and respiratory discomfort.