Hoe, hoe, hoe ….. its Christmas time and a good time to expose myths about Christmas trees. How do you keep Christmas trees hydrated? Should you add diapers to the tree stand? Are artificial trees more eco-friendly? Do they still contain lead? Can you reuse trees grown in pots? How do you cut the bottom of the tree? These and many more questions will be answered in this holiday gift to you.
Home Remedies for Keeping Trees Fresh
Lots of additives have been suggested to keep your tree fresh including commercial tree preservatives, molasses, sugar, bleach, soft drinks, aspirin, honey, ketchup, corn syrup and fertilizer.
None of these work better than plain water. In fact, several including commercial products increase the loss of needles.
If you hear about another home remedy not listed here it probably does not work.
Hydrogels (baby diapers) Keep Trees Hydrated
Hydrogels are also referred to as hydrogel crystals, water jelly crystals, root watering crystals, water retention granules and water-absorbing polymers. The material inside a baby diaper is a hydrogel and many sources suggest using this material to keep plants watered.
It doesn’t work for Christmas trees or other plants. It has no place in the garden, in a plant pot or in a tree stand.
Anti-transpirants Prevent Water Loss
Anti-transpirants are commercial products that are sprayed on trees to prevent water loss through the needles. They do clog the stomata for a very short period of time which reduces some water loss, but the effect is short lived. Stomata in the needles open and close as needed and quickly overcome the spray.
Anti-transpirants don’t work.
Treat Like Cut Flowers
Cut flowers are kept fresh by adding a preservative to the water. Why is this not used for Christmas trees?
Cut flowers quickly produce a substance called callose, a carbohydrate that plugs up the end of the stem. An acidic preservative added to the water keeps callose from sealing off the xylem. Christmas trees and other woody plants do not produce callose and the xylem in trees stays open much longer. A preservative will not help.
According to Dr. Warner, associate professor of forestry at the University of Wisconsin-Stevens Point, evergreens do excrete resin that naturally seals the cut after a week and a half, so very little water is absorbed after that point. That explains why trees stop drinking water after about a week.
Use a Diagonal Cut on the Trunk
Most people cut the end of the tree with a perpendicular cut, but it is claimed that a diagonal cut allows the tree to absorb more water. This seems to make sense. A diagonal cut exposes more of the trunk which in turn should absorb more water. Unfortunately, this logic is false.
Think of the xylem as a bunch of vertical straws running up the trunk. Can you suck up more liquid through a straw with a diagonal cut or a perpendicular cut? Both are the same since the limiting factor is the diameter of the straw, not the shape of the opening.
The other issue with a diagonal cut is that the upper section will be exposed above the water line sooner since it is higher up in the tree stand. Once exposed it stops pulling up water for the tree.
Stick with a perpendicular cut. The cut should be made within 12 hours of setting up the tree. Cut off at least 1/4″ to ensure fresh xylem is exposed.
Don’t Remove Bark
To improve water absorption some people suggest stripping the bark off the lower 6″. This exposes more cambium layer which helps absorb water, or at least that is the claim that is made.
Bark is also cut off to fit the tree in the tree stand.
Do not cut any of the bark off. If you don’t cut deep enough to reach the xylem no water is absorbed from the side and if you do cut deep enough you will damaged the Xylem.
Potted Christmas Tree
Instead of killing a live tree why not use a potted one? After Christmas you can then plant it in the garden.
The problem is that evergreens need a cool period during the winter to grow properly the following spring and they don’t like to come into your warm home for 6 weeks. The warm temperatures will cause the tree to grow and when you take it outside after Christmas the new growth will be damaged by the cold.
If you’re willing to have the tree in your home for 2 weeks or less and you have a place to plant it in spring, buying a potted Christmas tree is a good option.
Most gardens are not big enough to accommodate a new large evergreen each year. An alternative is to have a company grow it for you and bring it back each year but that adds to the environmental footprint. Is this really any more eco-friendly than using a live tree? Probably not. And the service probably costs as much as a new tree.
Don’t Kill a Live Tree
A lot of people use an artificial tree because they don’t want to kill a live tree. It is important to remember that Christmas trees are a farmed crop. They are grown specifically for harvesting.
What happens when a tree is harvested? Most tree farms will plant more seedlings for future harvests. You are not killing a tree; you are providing space for a new baby tree to grow.
A forest is an ecosystem where trees are continually dying and being replaced with new trees.
Real Trees Aggravate Allergies
It is common to hear about allergies to Christmas trees but according to National Institute of Environmental Health Science and the American Academy of Allergy, Asthma & Immunology the reality is that few people have such allergies .
Evergreens don’t produce pollen in winter and pine pollen is not a known allergen.
It is much more likely for people to have allergic reactions to the mold and dust found on reused fake trees than to have a reaction to real trees.
Real Christmas Trees End Up in Landfills
This certainly does happen, but many localities have some type of recycle program. Even without one, trees can simply be left in woods or fields to decompose on their own. There is no excuse for them to end up in landfill.
Years ago it was customary to have a big tree burning event after Christmas. This is great fun but terrible for the environment since it releases CO2 into the air.
Most real Christmas trees are recycled.
Christmas Trees are a Fire Hazard
There is a concern about real trees causing a house fire and each year we see examples of this on the news. The reality is that this is a very rare occurrence. The National Fire Protection Association reports that only 0.001% of real Christmas trees cause a fire.
Artificial Christmas trees have fire retardants added to the plastic used to make them. For this reason they are perceived to provide a safer option, but 28% of home fires involving a Christmas tree are due to fake ones.
To reduce the likelihood of a fire with either kind of tree, keep trees away from heating vents and fireplaces, keep them hydrated, and turn off lights at night.
Real Christmas Trees are Cut Down from Forests
There are nearly 15,000 Christmas tree farms In the US and Canada, growing almost 500,000 trees. Only about 2% of real Christmas trees are harvested from natural locations and many of them come from areas that need to be thinned to control forest fires.
Artificial Christmas Trees Contain Lead
Most artificial trees are made from PVC plastic and manufacturers add lead to make the plastic flexible. There are numerous warnings on the net about the dangers of lead in these trees. Is this really a concern?
California thinks so. Any PVC that contains lead has to be labeled with a special warning, “Handling this product exposes you to lead, a chemical known to the state of California to cause cancer and birth defects or other reproductive harm.” This is part of the crazy situation in California that requires labeling of anything that might be harmful. Other products made from the same plastic include computer power cables, phone cables, some cell phone cases, binders, raincoats, boots, garden hoses, inflatable pool toys, soft plastic toys, Christmas lights and the list goes on.
In a 2004 study Dr. Richard Maas found lead after wiping the floor under artificial trees that had been standing a week. He commented that “Results from these experiments show that, while the average artificial Christmas tree does not present a significant exposure risk (to lead), in the worst-case scenarios a substantial health risk to young children is quite possible.” It should be noted that lead in PVC has been dropping since 2007.
Lead does pose a health risk but the reality is that many things in our daily lives also expose us to the same level of lead. Nobody stops using power cables because of the risk even though they are used 12 months of the year. We have not banned the use of inflatable pool toys even though children are at a higher risk than adults.
In recent years, companies have started finding replacements for the lead and new trees will have less of an issue than older ones. Real Christmas trees don’t have a lead issue until you add the lights. The wire used in them contains lead.
Real Trees are Loaded with Pesticides
Growing trees is like any other agricultural crop and pesticides are used when required. Evergreens are fairly pest free and farmers don’t use pesticides if they don’t need them because they cost a lot of money. IPM procedures for evergreen farms focus mostly on non-chemical controls. There is no need to spray them immediately before harvest, so by the time you get them, the risk from any pesticide is very small. The spinach you buy probably has higher levels of pesticides and it is not a health risk.
This is a red herring promoted by companies trying to sell fake trees.
Sustainability; Real Christmas Tree vs Fake Christmas Tree
This is an ongoing debate but the consensus from most sources is that real trees are more sustainable. One study from Canada found that the production of a real tree produced half as much CO2 as an artificial tree, assuming that the real tree was burned after Christmas. If it is mulched the short term CO2 production would be even more favorable. A study by Swedish researchers found that, considering all the inputs, a real tree is five times more environmentally compatible than an artificial tree.
Artificial trees would need to be used for 20 years before they are more eco-friendly than real trees.
Update: Dec 2021. A new study comparing real to fake concluded that there is very little difference between the two, provided you keep the fake one for a few years. The real harm to the environment was driving to get the tree, “But above all, try to buy a tree close to home! The environmental effects of your trip to the tree lot, or Walmart, far outweigh the effects of the tree itself.”
Pros for Real Christmas Trees
Absorb CO2 and sequester carbon while growing
Grown on no-till soil which slowly accumulates carbon
Usually grown on land that is not suitable for other crops
Shorter transportation from local sources compared to fake trees that are imported mostly from China
Tree farms provide refuge for wildlife
Cons for Real Christmas Trees
Fertilizers and pesticides are used
Recycling increases carbon footprint (transportation and chipping)
Need to be replaced every year
Pros for Artificial Christmas Trees
Can be used for many years, although average use is only 6 to 9 years.
Cons for Artificial Christmas Trees
Long transportation routes, usually from China
Mostly made from PVC plastic, which contains lead, phthalates (hormone-disrupters) and other VOCs
Decompose very slowly in landfills
There are numerous myths and stories explaining the origin of Christmas trees.