By Kassidy Robinson and Bill Jacobs
Did you know that New York State ranks #4 in the U.S. in acres dedicated to growing Christmas trees? There are nearly 19,000 acres of Christmas tree farms, according to the New York State Department of Agriculture and Markets. This important agricultural sector has a $13.8 million economic impact for New York. To top things off, the most famous Christmas tree in the world, the Rockefeller Center Tree, is grown in our state.
In the 1850s, when Christmas trees first became popular, anyone who wanted a tree went out into the country and cut one down in the woods. In 1851, a clever business person in the Catskill Mountains began harvesting Christmas trees and selling them at the Washington Market in Manhattan, establishing the first mass-market sale of Christmas trees in the U.S. Before long, Christmas trees were so popular that conservationists became concerned about over harvesting, and people were dissuaded from buying them. That was until the first Christmas tree farms were launched in the early 1900s, making Christmas trees a renewable resource.
But there is a grinch in this story. In fact, dozens of invasive grinches may be lurking at Christmas tree farms and wherever trees are found. The USDA Christmas Tree Pest Manual, Second Edition, lists more than 50 “pests” of Christmas trees. Some are native species, such as porcupines and woodpeckers. Others are invasive species. Here are three from LIISMA:
- Elongate Hemlock Scale (Fiorinia externa)
This armored scale insect was introduced to New York City (NYC) in 1905 and has since spread through the Northeast, affecting primarily hemlock trees and other conifers that grow nearby. Elongate hemlock scale (EHS) can be spotted on the underside of needles as small flat brown or white scales or as yellow eggs. EHS affects trees, including Christmas trees, by draining the needles of nutrients and water, resulting in needles turning yellow and dropping.
- Spotted Lanternfly (Lycorma delicatula)
This brightly adorned insect would fit right in amongst the ornaments on our Christmas trees this season. While the spotted lanternfly would prefer plants such as ailanthus, grapevines, and apple trees for their holiday feasting, they may use Christmas trees for egg laying and then be transported to new habitats this winter. This pest is still new to Long Island and efforts are underway to monitor their movement and potentially develop management strategies.
- Hemlock Wooly Adelgid (Adelges tsugae)
This invasive scale insect has been slowly causing the decline of eastern hemlocks (Tsuga canadensis) since the 1980s. An infested tree will have visible white fluff on the undersides of branches in winter where the adelgid eggs are present. Hemlock wooly adelgids sap nutrients, cause thinning canopies, and prevent new growth. While hemlock trees are not typically grown as Christmas trees due to conservation concerns and slow growth rate, spotting their magnificent splash of green on the winter landscape can certainly feel festive. LIISMA continues to work toward protecting our remaining hemlocks and scouts for potentially adelgid resistant trees.
What can people do? Buy locally!
Sourcing Christmas trees from local farms is a great way to support small businesses and reduce the likelihood of spreading invasive species to new areas. Trees purchased from big box stores may originate from out of state, so there is a high risk of introducing new pests by this method. There are many tree farms on Long Island and near NYC to choose from for your farm-fresh trees that have a lower risk of introducing new species.
Keep on the lookout for hitchhikers!
If your tree is unhealthy or has some unusual symptoms, it could be an invasive tree pest or fungus. Inspect your tree for invasives and document anything you find on iNaturalist or iMapInvasives.
Properly dispose of your tree!
Christmas trees and woody landscape debris make wonderful brush piles for wildlife in backyards. They will decompose naturally. Christmas trees can be reused outside as bird feeders, decorated with pine cones full of peanut butter and bird seed. Alternatively, check your municipality to find out the best way to dispose of your tree. Some make trees into mulch, bring to a landfill, or even up-cycle trees into an erosion stopping sand dune by burying them on the coast. By following proper disposal methods for your tree, you are doing your part to prevent potential pests on your tree from being introduced into natural spaces.
Sources:
Amelinckx, A. (2018, October 19). Here’s Why Your Christmas Tree Comes From a Farm. Modern Farmer. Retrieved December 28, 2022, from https://modernfarmer.com/2016/12/heres-christmas-tree-comes-farm/
Gruber, P. (2018, October 19). NJ Allays Lanternfly Christmas Tree Worries. Lancaster Farming. Retrieved December 28, 2022, from https://www.lancasterfarming.com/farming-news/news/nj-allays-lanternfly-christmas-tree-worries/article_2c88f50d-6f6e-5697-9d6e-0f85a2276db9.html
NYS Department of Agriculture. (2022, November 21). It’s the holiday season: Tree Cutting Tradition promotes NYS Christmas Tree Farms and kicks off the festive season. Agriculture and Markets. Retrieved December 28, 2022, from https://agriculture.ny.gov/news/its-holiday-season-tree-cutting-tradition-promotes-nys-christmas-tree-farms-and-kicks-festive
Parks, N. Y. S. (2019, March 6). Invasive species spotlight – elongate hemlock scale. New York State Parks Blog. Retrieved December 28, 2022, from https://nystateparks.blog/2018/07/14/invasive-species-spotlight-elongate-hemlock-scale/
USDA. (2004, December 6). Cornell Cooperative Extension. Cornell Cooperative Extension Oneida. Retrieved December 28, 2022, from https://cceoneida.com/resources/christmas-tree-pest-manual
