Every once and awhile I try and do some ‘big tree’ hunting in British Columbia. I’ve discovered something a bit distressing when I do find these big trees. Almost always there is an English Holly (ilex aquifolium) growing somewhere near the Big Tree. It doesn’t matter how deep or untouched the forest is. If there is a known big tree that people hike out to see, then there will a Holly there.
This is distressing because how the hell did Holly get there?! How did this Invasive European tree establish itself in a BC old growth forest? Forests known for their lack of tree diversity and dense shade. Forests that where trees are limited to giant, ancient coniferous trees. Where every other plant within view is a native plant. Plants that have existed in BC for thousands of years. How did Holly, a plant that has only been in BC a hundred years or so, a plant that evolved on the the other side of the ocean in a different habitat and ecosystem, a plant that is- unbelievably – growing in the dense shade of one of the most competitive forest environments in the world. How the hell did it get here? How can it survive?
Holly’s survival tricks are the same things that make it such a devastating invasive species. Its thick, glossy, spikey leaves deter animals from eating it and humans from removing it. The density of its leaves and its ability to quickly re-sprout from roots or branches allows it to form dense thickets that outcompete other plants. Its roots use a heavy amount of water and nutrients, and release sulfur, drying out and poisoning the soil. But by far the best and most devastating trick it has are its bright red berries.
The red berries of Holly (not technically ‘berries’, they are drupes, but commonly still called berries) are real reason why Holly is here in BC. Holly has a unique evolutionary adaptation with its berries. They are important food source for birds, but birds don’t enjoy eating them. They are bitter, hard, and toxic if too many get consumed. The same chemicals that make the berries unpalatable, however, also make the berries hardy and durable. Allowing them to be one of the only food sources left at the end of winter when birds have exhausted their food caches. During winter and start of spring, before insects begin reproducing and plants flowering, there is a lot of food stress on birds. Holly berries help the birds survive, but in exchange, it means the seeds of Holly are widespread over large areas as birds excrete them out as they hunt for more food.
What a strange survival trick! Holly plays the long-term game, betting on scarcity improving value, while most other plants choose the short-game of tasty fruit that gets eaten quickly.
A 2010 study showed that in the Pacific Northwest, American Robins are by far the biggest consumer of Holly berries. Especially between the months of November and February. American Robins are one of the few lucky birds to see their populations increase along with humans. The big reason for this is Lawns. Patches of grass, cut short, that allow easy access to worms and insects in the soil, aren’t a thing that occurs naturally. With suburbs we have created free buffet lines for Robins. They’ve become so comfortable with us that they often nest, with their beautiful bright blue eggs, right on house porches.
(Also as aside I should mention here that consuming Holly berries may lead to mass robin die off. There was a 2023 mass death of 55 American Robins in Virginia that the cause was believed to be from consuming Holly berries that had fermented and led to to ethanol toxicity. The risk is this high and yet robins still mass consume the berries!)
However, just like robins are irresistibly attracted to Holly berries, so are we. A branch of Holly, with its dark green spiky leave and bright red berries, has become universal symbol for Christmas. Holly is symbol that was adopted from Pagan Europeans when they were conquered by Christians. Pagans saw the Holly berries and leaves surviving over winter as a reminder that winter will end and spring will come. A symbol of hope and rebirth. To hold on a little while longer. The bad is only temporary. Surviving winter is a still a challenge for many of us, but not near what it used to be in pagan times, when if the winter got especially cold or long, your sources of food and heat might run out.
Pagans’ relationship to Holly is much like American Robins to Holly now. Holly was a gift to get you through the winter.
The Christian adoption of the Holly as a symbol of hope and rebirth – like the Christian adoption of a similar symbol: a small coniferous evergreen tree cut down and moved inside – slightly change the interpretation to mean the arrival of a savior rather then the arrival of spring. Holly berries still meant Hope though.
So it’s no surprise that with the arrival of European immigrants in B.C. – with the hardships they faced leaving their home country – that they brought along these living symbols of hope and survival. And to these immigrants surprise and pleasure, Holly loved growing in B.C.
So much so, that massive Holly Farms were established on Vancouver Island in the late 1940s and 50s. They would harvest and sell Holly branches as Holiday Decorative Foliage all over the world. Taking advantage of ’empty’ land from clear cuts during the World Wars, in the 1960s there were at least 27 different Holly Farms on the Island. One just outside Victoria was four and a half acres of Holly Trees.
Holly was also mass planted on the Vancouver Mainland. Hollyburn Mountain and the Hollyburn Neighborhood in West Vancouver get their name from John Lawson a ‘founding father’ of West Vancouver, who loved and planted the non-native Holly Trees. ‘Burn’ is a a Scottish term for creek or small river. ‘Holly-burn’ became a good descriptor of West Vancouver, with all its mountain creeks and planted Holly trees.
When the Van Dusen Botanical Garden was established in the middle of Vancouver in 1975, the gardeners quickly began working on collecting one of the biggest Holly collections in world. In 1988 it was designated an official Holly Arboretum by the Holly Society of America. This was a likely a huge Holly seed source that allowed Holly to take over the city, much like the Holly Farms on Vancouver Island did. To their credit, Van Dusen removed a large amount of its Holly Trees in 2010 when it became known as a notorious invasive plant.
In Pacific Spirit Park, Holly was well established by at least 1977. In a 1977 publication about the forests in Pacific Spirit Park (then still called the UBC Endowment Lands), Holly is the only non-native species listed in the book, with the authors saying:
Holly (ilex aquifolium) orignally from Europe, is a common garden and hedge plant and has been distributed by birds and mammals. It is widely scattered throughout the UEL [University Endowment Lands] and is particularly common in mixed forests.
Holly not only was spread by birds, but it was also actively planted in forests in some early conservation efforts in Vancouver. I have heard a few rumors about this and found some proof of this happening in a 1982 edition of Nature Vancouver’s Discovery Magazine. Holly was actively planted along with native species like Maple, Cedar, and Dogwood in the Surrey-White Rock area. Strange to just plant one non-native species while the rest are native! The rationale behind this seemed to have been that Holly was believed to be very important to the local birds. Once again, Holly’s trick of using winter scarcity helped it become widespread.
We now have a nice long list that makes it clear that human hubris is holds a lot of blame here in the Holly Invasion of BC. I am using the word ‘hubris’ here in the Greek tragedy sense of ‘defiance of the gods’. Our mass spread of Holly was a defiance of nature, and we are paying the price.
What can we do? Well, Pacific Spirit Park Society came into existence with the help of the ‘Holly Haulers’ a volunteer group doing invasive species removal, focusing specifically on Holly.
Here is current B.C. Premier, David Eby, giving the Holly Haulers a shout-out in 2014 before he became premier:
I am still stunned by how common Holly is in Pacific Spirit Park, despite it being so actively removed consistently and frequently. It really shows just how entrenched it is.
BC doesn’t currently make it illegal to sell or plant highly invasive plants like Holly. You can still walk to your local gardening store, buy a Holly, and plant it on your lawn. Hopefully this will change in the future, as the BC Government has committed to work toward this after a 2023 request for a ‘Ban on the Sale of Invasive Plant Species’ from The Union of BC Municipalities.
It’s a bit ironic now, that when I see Holly used as a Christmas decoration, it is supposed to – at its core – symbolize the ability to survive hardship. It now symbolizes humanities ability to create hardship. I wonder what the pagans would think.