Deck the Halls (With Proper Caution)

The holiday season is steeped with tradition and plants play a very prominent role in many cases. Indeed, for many the season would not be complete without having the likes of evergreens, holly, mistletoe and other traditional plants adorning their homes at this festive time of the year. It is important that care is exercised in the use of certain of these plants since we want the holidays to be happy and safe.

The use of evergreens (greenery) and other plants in Christmas decoration actually can be traced to pagan practices of the pre-Christian era associated with the winter solstice, or yule, which typically occurs December 22nd. In days of old, however, these materials were rarely brought into the home before Christmas eve and to do otherwise was considered "bad luck" for the coming year. This meant that the greenery and other plant material used still were fresh for Christmas Day and posed much less of a fire hazard - a definite "must" when one considers the primary source of illumination during that era was through the use of live candles. Today, the holiday season starts with Thanksgiving and lasts through New Year’s Day. Greenery and other cut plant material brought into the home at the beginning of the season is likely to get very dry by the time New Year’s Day arrives could pose a fire hazard if improperly used.

Proper care will not only make greenery safer indoors but will add to its attractiveness. Evergreen needles turn brown and holly leaves blacken as they age, therefore it is important to start with greenery as fresh as possible. While relatively fresh greenery might be available from a local retail outlet, the very freshest is that which is gathered from one’s own landscape and this should be done whenever possible. If the latter is unavailable, purchase greens just as soon as they become available. Homeowners generally can take better care of greenery than the people who have an abundant inventory to care for on the sales lot. After purchasing, re-cut the stems and place the cut ends of the greenery in buckets or tubs of water. Keep the plant material in the coolest place possible until it is time to move it indoors. Freezing temperatures will not harm the greenery but unfrozen water should be available to the stems at all times during storage.

To promote safety and prolong the useful life of holiday greenery indoors it is best to keep the stems in water if at all possible. Decorations should be designed so that branches fit into a container that holds water. Floral preservatives such as those used for cut flowers can be added to extend further the life of the greenery. Changing the water on a weekly basis is a good idea since water can become foul if allowed to sit. The foul smell comes from bacteria and other microorganisms present which will block vascular tissue and retard the ability of the greenery to uptake water. Additionally, never place decorations containing greenery near sources of heat such as hot air ducts, radiators or appliances that produce heat. Avoid locating decorations containing greenery near fireplaces where sparks from an open flame might ignite them.

Another aspect of safety in the use of plant material in holiday decoration involves knowing which traditional plants contain toxic compounds that might represent a health risk, especially if children are present. For example, the fruit (red berries) of holly (Ilex aquifolium) are considered mildly poisonous and can cause nausea, vomiting and diarrhea if ingested because of a compound called illicin. These bright berries are quite appealing to young children who tend to explore their world through the sense of taste as well as sight. Therefore special care should be taken if holly is used in seasonal decorations in households with small children present. Keep the holly well out of the reach of youngsters and make sure that any berries that might accidently fall from the decoration cannot fall to the floor and be retrieved by a curious child. In a previous article we mentioned that (especially) the leaves of mistletoe (Viscum album) contains toxic viscoproteins are considered poisonous. Again, if mistletoe is used for holiday decoration keep it well out of the reach of children. The leaves, bark and seeds of yew (Taxus baccata and T. cuspidata) contain alkaloids known as taxines which are toxic. Yew produces a small red fruit which might be attractive to children. While the pulp of the fruit is harmless the seeds, if chewed to release taxine, can be quite toxic.

Other examples of plants frequently associated with the holiday season that are known to produce toxic substances include English ivy (Hedera helix) whose leaves contain a toxic compound known as saponin, Juniper (Juniperus communis and J. sabina) which produces slight amounts of the diuretic compound terpineol in its seeds, and White Cedar (Thuja occidentalis) whose leaves produce an essential oil similar in nature to thujone which is the toxic compound produced by wormwood (Artemesia). Poisonings from this latter group of plants are extremely rare due to the relatively low levels of the toxic agents contained by these plants.

All of the above is not meant to cause readers to utter "bah, humbug" relative to decorating for the holiday season or to go out and purchase artificial plant material. People have been using plant material as part of their indoor decoration at this time of the year for centuries and, hopefully, will continue to do so for many centuries to come. This article is simply a reminder that "prevention is the best cure" when it comes to any sort of unfortunate mishap and education is key to prevention. Happy holidays!

David Trinklein
Associate Professor Plant Sciences