It’s that time of year again: the time for massive light displays that sound like cash registers ringing to electric companies. That’s right; it’s getting to be the Christmas season (even though retailers would have you think it starts in September).
Listening to always agitated Mike McGrath on the You Bet Your Garden podcast, he said something interesting on the episode from November 14 (Indoor Citrus). It’s stuck with me over the last several hours, and the more I thought about it, the more it makes sense, especially this time of year:
Christmas lights can, potentially, awaken outdoor, dormant trees when the lights are strung around them.
A lady called in to ask about whether or not she was doing too much damage to her hydrangea trees. During the time that her phone call lasted, she mentioned that she trimmed her tree after removing the Christmas lights. This prompted McGrath to comment that having the lights on there for 6-8 weeks, for potentially 10 hours a night; this could easily bring the trees to break dormancy.
Trees begin going dormant around 40 degrees Fahrenheit, and during this period, growth is halted and you can prune most trees. However, if you bring that tree out of dormancy, and it starts creating new cells for growth, as soon as the lights are gone or there’s a cold spell that overpowers the warmth of the bulbs, it’s going to start doing damage.
Now, when I say Christmas lights, I am referring to the incandescent bulbs, not the LED ones. It’s the warm of the bulbs that we want to pay particularly close attention to. So, when you run your lights this year, make sure you think about what you’re using and how much you care about your trees.