The author of the text is Patryk Strzałkowski, a journalist for Gazeta.pl.
As far as the eye can see, lush, yellow flowers bloom, especially at a time when few other plants are flowering. This is partly why Canadian and late goldenrods have become popular as ornamental plants in gardens and are used by beekeepers. However, unlike the native goldenrod, these two species are foreign and invasive in Poland.
Canadian goldenrod, like many other invasive plants, was deliberately brought to Europe (from America) several hundred years ago. It began spreading from gardens, and now it is so abundant in Poland that it has become a recognizable part of the landscape.
More Goldenrod, Fewer Birds
However, these tall, yellow flowers come at a price for Polish nature. The invasive goldenrod causes a range of ecological problems, explains Dr. Magdalena Lenda from the Institute of Nature Conservation of the Polish Academy of Sciences, who has been studying the issue for a long time:
"A few years after it appears in a given place, it can already form a dense monoculture where nothing else grows. Goldenrods bloom all at once, mainly in July or August, but before that, the area is a 'desert' in terms of food for pollinators. During a season that is crucial for our native pollinators, such as wild bees, there are no native flowers, and therefore no food for them."
This triggers a cascade of consequences because everything in nature is interconnected. As Dr. Lenda explains, pollinators (for example, butterflies and their larvae—caterpillars) are a very important food source for birds. "So the food base for birds is reduced, especially during the critical period of feeding chicks. Additionally, most birds are less likely to nest in goldenrods. The result is that in a landscape dominated by goldenrod, there are fewer birds than in an extensively managed agricultural landscape," she says.
Goldenrod can quickly dominate the areas where it appears, thanks to several characteristics. The first is rapid growth, and the second is a mechanism that allows it to suppress competing plants. According to Dr. Lenda, Canadian goldenrod can release substances into the soil that are toxic to other plants, allowing it to take over their space.
Beekeepers: Since It’s There, We Use It
Although Canadian and late goldenrods are officially listed as invasive alien species, their flowers are sometimes used by beekeepers. Beekeeping websites provide information on how to use them as a resource for bees. And it’s easy to find solidago honey for sale online.
Sellers and some websites also praise its alleged medicinal properties, although there is no scientific evidence in the literature to support this. Scientists and environmentalists are concerned that the growing demand for solidago honey—boosted by the promotion of its supposed health benefits—at the very least hinders efforts to manage the invasive goldenrod, and at worst, may contribute to the spread of the problem.
Tadeusz Sabat, president of the Polish Beekeeping Association, does not believe that beekeepers are to blame—since they are merely using the goldenrod that grows regardless. "For now, we use it, and if there is an order to mow or destroy it, then we will stop using it," he assures.
Sabat explains that in late summer - and until a few years ago, goldenrod bloomed later, in September - the flowers and pollen of goldenrod are useful to beekeepers. Not only do they produce honey, but they also provide bees with nutrients at a time when there are few other flowers. This means beekeepers don’t have to completely artificially feed the bees as they prepare for winter. "In a certain period, it saves bee colonies," he says.
However, he recognizes the problems associated with goldenrod, such as the decline in biodiversity, which, as he emphasizes, is "a joy for beekeepers." But in his opinion, the problem is not producing solidago honey but rather the "neglect of agricultural land," on which the invasive plant spreads. "So it’s good that beekeepers are using what’s available, so bee colonies aren’t weak going into winter. But the state should allocate funds for mowing goldenrod. That’s the direction that should be promoted," he believes.
Bees Help Goldenrod
Sabat says that solidago honey yields are often "poor," and that beekeepers usually don’t specifically choose areas with goldenrod. However, Dr. Lenda fears that the greater the demand for solidago honey, the more beekeepers will transport their bees to such places and "assist" the invasive goldenrod. And on beekeeping forums, one can find both those who write about the negative effects of the invasive species and those who transport their bee colonies to goldenrod fields.
Such a situation could be dangerous for nature, as it helps spread the plant. As the researcher explains:
Sometimes there are even dozens of hives, and the honeybee is the most effective pollinator for goldenrod. So alongside honey production, we have very efficient pollination and seed production, which can be carried by the wind for several kilometers.
Therefore, the production of solidago honey helps the plant and promotes its spread. Moreover, as the scientist says, it’s not always the case that beekeepers only use already established goldenrod. "Years ago, when goldenrod was not yet so widespread, we checked beekeeping forums as part of our research, and some were discussing how and where to plant goldenrod for bees" - she recalls. Tadeusz Sabat assures that he is not aware of such cases.
Report and Mow
Maps of Canadian goldenrod occurrence in Poland show both isolated points and entire areas in various parts of the country, even in protected and valuable natural areas like the Kampinos Forest near Warsaw. Dr. Lenda points out that many researchers in Poland believe the situation with goldenrod is so bad that it’s not worth fighting it anymore because we won’t get rid of it. "But if we do nothing, goldenrod will spread even more, even occupying areas in national parks. In my opinion, it’s very important to take action to remove goldenrod, especially in areas of high natural value," she emphasizes.
Although goldenrod is an increasing problem, there are no top-down actions, such as from the authorities, to support its removal. "But we can effectively get rid of it, for example, by mowing or grazing animals, and it’s worth doing, especially in and around valuable natural areas," the researcher says.
A good method, used by some farmers, is to plant corn on areas previously occupied by goldenrod," the scientist adds. The head of the beekeepers' association, on the other hand, points to sunflowers, which could be planted in areas taken over by goldenrod and be useful to beekeepers. "Even if sunflowers produce less nectar, their pollen is excellent for bees to use in winter
- he says.
What we do in our gardens also matters. Even a clump of Canadian goldenrod growing there can spread. "One goldenrod flowerhead can produce several hundred seeds. If someone has goldenrod and doesn’t want to get rid of it, they should at least prevent seed formation and break off the flowerheads after they have bloomed," Dr. Lenda advises.
Greenpeace Poland has created a special page about invasive goldenrod. There you can find information on how to distinguish it from native Polish goldenrod (the plants are clearly different, so there’s no need to fear confusion) and what can be done with it. Anyone who observes Canadian goldenrod in their area can report it on a special map and will receive a notification when it’s a good time to mow it.
