Seasons

Plant Hazards to Avoid this Holiday Season

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 By Nick Goltz, DPM, UConn Home & Garden Education Center, UConn Plant Diagnostic Lab

Tree with lights
Using low-heat LED lights is a great way to reduce fire risk while keeping things festive. The stewards of this tree took the extra step of installing a rope fence to discourage visitors from damaging the tree or lights. (Photo taken by Nick Goltz)

Using low-heat LED lights is a great way to reduce fire risk while keeping things festive. The stewards of this tree toko the extra step of installing a rope fence to discourage visitors from damaging the tree or lights. (Photo taken by Nick Goltz)

With the holidays upon us, many of us are focusing, with good reason, on last-minute gifts, travelling, reconnecting with loved ones, and all the joy and stress that will inevitably come with it. With all the hustle and bustle of the season, it can be easy to overlook some of the safety hazards that also come about this time each year, especially those involving the holiday plants that we rarely give a second thought.

On countless desks, coffee tables, and, in warmer climes, doorsteps, you are likely to encounter at least a dozen poinsettias this December. Poinsettias (Euphorbia pulcherrima) are some of the most conspicuous and popular plants associated with the holiday season here in the US. They are often thought to be highly poisonous if ingested. While ingestion may cause some mouth and skin irritation and gastrointestinal upset, sometimes with some associated vomiting or diarrhea in small animals, poinsettias are vastly “overhyped” with their supposed toxicity.

There is no documented case of human fatality associated with poinsettia ingestion, and most calls to poison control lines for ingestion report no adverse symptoms whatsoever. Medical intervention is usually unnecessary for people or pets that ingest the plant, except for those with allergic reactions to related plants (particularly those with latex sensitivity). For more information on poinsettias and their fascinating history, see Heather Zidack’s column from mid-November, “Poinsettias: The Story of a Holiday Treasure”. While poinsettias may be overblown with regard to their supposed toxicity, other common plants one might see around the holidays, including amaryllis and mistletoe, are quite toxic to humans and pets if ingested.

What we call “amaryllis” in most stores and garden centers is likely not the true South African amaryllis (Amaryllis belladonna), but rather a related South American plant in the genus Hippeastrum, which has been cultivated more extensively and has a greater number of cultivars on the market. Both are bulbous tropical plants that bloom in winter in the northern hemisphere, and both are poisonous if ingested. The bulb, commonly sold waxed or bare in stores around the holidays to be used as a table centerpiece or hostess gift, is especially toxic and should be kept away from pets and children. If you’re curious to learn more about the history and cultivation of this holiday plant, check out Dr. Matt Lisy’s recent blog post, “Amazing Amaryllis” on the UConn Home & Garden Center’s very own Ladybug Blog (https://uconnladybug.wordpress.com/).

Though in antiquity it represented fertility and offered protection from evil, mistletoe (usually Viscum album, European mistletoe and Phoradendron leucarpum, American mistletoe) has been associated with Christmas since some point in the late 1700’s. Though lovers may steal a kiss or two beneath the mistletoe this Christmas, be sure the mistletoe can’t be stolen by children or pets as you decorate for your holiday party! Although European mistletoe is more toxic than American mistletoe, both plants are dangerous if ingested, particularly by pets and children, who may be attracted to the small white berries that have a high concentration of toxin. If you know someone that accidentally ingests a plant not known to be edible, be sure to contact the poison control hotline by calling 1-800-222-1222 or by visiting https://www.poison.org. For pets, contact the ASPCA poison control hotline by calling 1-888-426-4435 or by visiting https://www.aspca.org/pet-care/animal-poison-control. Conveniently, they have a poisonous plants list on this site that you can reference as you shop at your local nursery or garden center.

Though thankfully Christmas trees (typically fir, pine, or spruce) are not known to be toxic to pets if ingested, the sharp needles can cause injury if ingested and the trees themselves can pose other hazards if not maintained with care! If you have a pet that likes to chew through wires (there is a scene in a famous Christmas movie that likely comes to mind), be sure to keep those out of reach, or perhaps opt for battery-powered illuminating ornaments. For their safety and yours, cats and birds should always be discouraged from climbing or flying into your tree!

Finally, though we all can appreciate rustic and vintage holiday décor, another strategy to reduce the risk of fire this holiday season is to upgrade your string lights to low-heat LEDs. Whatever type of string light you use, unplug it before you go to bed to help reduce fire risk. If you use a live tree, be sure to keep it watered as dehydrated trees are more likely to catch fire.

With these tips in mind, the Plant and Soil Health team at UConn wishes you and your loved ones a safe, joyous, and restorative holiday season! For questions regarding winter plant safety or for any other gardening questions throughout the year, contact the UConn Home & Garden Education Center for free advice by calling (877) 486-6271, toll-free, visit our web site at www.homegarden.cahnr.uconn.edu/, or contact your local Cooperative Extension Center.

Is Early Leaf Drop an Indicator of Tree Health?

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By Nick Goltz, DPM, UConn Home & Garden Education Center, Plant Diagnostic Lab

Trees showing their autumn colors
Trees showing their fall colors. Photo by Nick Goltz

The autumnal equinox, one of two times of the year at which day and night are equal in length, just passed on Sunday the 22nd. While this point marks the astrological start of fall, many of the trees lining the roads on my drive to work (and in many of our clients’ yards) seem to want to get a head start on the season. Since late August, we’ve been getting calls from folks across Connecticut asking why the leaves on their trees are changing color and falling early. You may even be thinking, “Hey, a few of my trees are dropping their leaves early too. Is that something that can indicate how healthy they are?” In a word, maybe!

First, let me share the good news that, for most trees, premature color change and leaf drop doesn’t mean that they are in any immediate danger. Plants, much like humans and other animals, respond to stress differently depending on their environment and the kind of year they’ve been having. Just like we might see a little hair loss after a particularly stressful few months, trees may drop their leaves early as a response to stress. Identifying what is causing the stress however, is important when deciding if concern is warranted.

What type of stressors might be causing this early color change and leaf drop? For most trees, the answer is water. Connecticut and several other states in New England had a series of heavy rain events and flash flooding throughout the summer. While we’ve had hardly any rain in the land of steady habits for several weeks now, for many trees, the damage has already been done and symptoms are just appearing now. Saturated soils deprived plant roots of oxygen, damaging them and making them more susceptible to disease. Plants in especially low-lying areas, caught in floodwaters, or grown in poorly-draining clay soils likely experienced the most damage and earliest leaf drop.  Some plants may have even perished outright from the damage. Besides water, excessive heat and the increased prevalence of fungal and bacterial diseases, as well as some insect pests, may have also contributed to the stress our plants are letting us know about now.

So, how can you know if the early color change or leaf drop is an issue for your favorite tree or just its way of complaining about a stressful summer? When and where the leaf change and drop is occurring can help you determine if the damage is likely a normal stress response or due to something more sinister.

Consider when the color change and leaf drop first began. In this instance, seeing some leaves begin to change in the last week of August is less concerning than seeing them change at the end of June. Plants that have their leaves change color and drop in midsummer or earlier are most likely dealing with a disease or pest issue, rather than a stress response. I recommend you get advice for these plants by contacting the UConn Home & Garden Education Center and remove them from your garden if they are unlikely to recover.

Also, consider what part(s) of the canopy was affected. Conifers such as white pine drop their leaves (we usually call them needles) in response to stress too, but you will typically see this take place on the interior of the plant – the older needles that aren’t capturing much sun anymore. Branches on deciduous trees, such as oak, that are in shady spots tend to drop their leaves early too, and this is normal.

Branches in full sun that lose their leaves very early, while others on the tree remain fine, are a bit suspicious. Mark these branches with tape or string and monitor them carefully as the plant produces its first leaves or flowers in the spring. If these marked branches do not produce leaves or flowers with the rest of the tree, get advice (again, by contacting the folks at the UConn HGEC)! The best option is usually to cut them close to the main trunk, then disinfect your pruning tools.

If you’re concerned about the health of your tree, including as a result of a potential disease or pest issue, practice good fall habits to give your trees the best foot forward next spring! Clean as much leaf litter as possible and remove it from the base of trees that dropped their leaves early. If you suspect the plant is diseased or has pests, throw away these leaves or burn them before composting. For example, many plant pathogenic fungi can survive the winter on fallen leaves and reinfect healthy plant tissue the following spring. It’s also a good idea to minimize added stress for your plants. Try not to expose them to herbicides, deicing salts, fertilizers, or other chemicals until they’re looking strong again.

If you aren’t sure how to proceed with your fall cleanup or if you’d simply like a second opinion on your favorite tree, get free horticultural consultation from the UConn Home & Garden Education Center by emailing ladybug@uconn.edu or by calling (877) 486-6271.