Doreen Fogle: Beware the surprising dangers of your landscape berries for the birds
One of our most popular landscape plants can actually kill birds. It’s a great utilitarian plant, too. It tolerates full sun to near full shade. Has cheerful clusters of white flowers in the spring, good for the bees. It’s deer resistant and drought tolerant, two qualities I require in my plantings. And it has very showy, shiny, bright red berries that last a long time on the plant.
But those showy, bright red berries are toxic to birds.
I’m talking about Nandina, sometimes called heavenly bamboo (it’s not bamboo, that’s a misleading common name). It was in 2009 that a voracious flock of cedar waxwings descended on a Georgia neighborhood planting of Nandina, and soon there were lots of dead birds.
The poor things were taken to a lab and studied. It turned out the berries produce a cyanide poison and other alkaloids. And due to the feeding frenzy the Cedar Waxwings are famous for, they stuffed themselves and then quickly died.
Not all birds eat the fruits of Nandina. They seem to know that they don’t taste good. But later in the winter when food becomes scarce, the red fruits look very enticing. This may explain the rare observations of the phenomenon seen in Georgia. And there is some scientific speculation that the fruits produce more of the cyanide poison in certain climatic conditions.
Meanwhile, the fruits are considered hazardous to dogs and cats. Humans can actually eat them, but the fruit must be removed from the seeds. So, beware. Another interesting fact is that some people eat the young greens, but only by boiling them twice in a complete change of water. Good to know, just in case!
These are not berries at all
Now, when I speak of berries, I should be saying fruits. Many of the winter bearing “berries” are actually pomes, fleshy fruits that surround a core, like apples. They’re small, round, red and we tend to think of them as berries. But they’re not.
Other winter fruits for birds also have deleterious effects
There’s something else a little hazardous about birds and their winter fruits. Many of the fruits are not edible until they’ve gone through a frost or a cool spell which renders them ripe. Some produce the cyanide poison, but are safe when ripe.
But what happens is that they ferment. So very often, especially at the end of the winter season, the birds are getting tipsy! Many people have observed this, watching the poor little birds eat and stumble back to a safe place to “recover.”
One hazard that has been observed is that plantings of winter fruits that birds love makes them so tipsy that they crash into buildings and die. This cause of bird death occurs anyway because of the way glass confuses the birds. But when drunk? It makes for hazardous navigation indeed!
The plants will escape into the wild
Birds are responsible for planting many plants. It’s the perfect system. Eat good fruits then fly all around looking for more good food, and excrete the seeds out all over the place. Planting more food for the future.
But this system was not created for all the imported plants we love so much. Many of them become invasive, growing in the wild at the expense of the native plants. The Himalayan blackberry and scotch broom we have around here are examples of this.
In my previous articles I have described how insects are pretty much at the bottom of the food chain and how the birds and many mammals and fish need them for food.
I also described how the insects need the native plants they evolved with for food. Without enough native foliage for the insects, there won’t be enough insects for the birds tosurvive.
So the spread of non-native plants is not a good goal. And often they can become invasive.
Nandina has become an invasive species in parts of the southeastern US.
But they do feed the birds.
BEST OF BOTH WORLDS
Many non-native plants do feed the birds without harm. Pyracantha, hawthorn, cotoneaster, barberries, privet, rose hips, and holly fruits are all enjoyed by birds.
But I often find many of these plants out in the periphery of our neighborhoods in the wild, taking up residence.
The best choices for plantings, is, of course to plant natives to help restore and maintain food for the insects and the birds. I described toyon as a great native landscape plant in my last article. I’ll describe more good choices in my next articles.
Doreen Fogle is a landscape designer and writer in Nevada County. More of her articles can be found on her website mydelightfulgardens.com and she can be reached at email@example.com.
Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.