Goldenrod is a familiar sight in late summer and fall across North America, with its bright yellow flowers blooming along roadsides and in fields But there is debate around whether this attractive wildflower acts as an invasive plant that causes harm The answer is not simply yes or no – different goldenrod species vary in their potential to spread aggressively.
Goldenrod belongs to the large Asteraceae plant family and the genus Solidago. There are around 120 species native to North America, some of which have become introduced and naturalized in Europe and Asia.
Certain goldenrod species do exhibit invasive traits under the right conditions:
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Rapid growth and reproduction from rhizomes, forming dense clumps that crowd out other plants.
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Prolific seed production – a single plant can produce over 100,000 tiny seeds that are easily dispersed by wind.
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Allelopathic chemicals emitted from roots that suppress neighboring plant growth.
However, applying the term “invasive” to native species like goldenrod is complex. Its spread is a natural process, not caused by human introduction like invasive exotic species. Goldenrod fills an important ecological niche and provides habitat for pollinators and other wildlife. So is it fair to label it as invasive?
How Goldenrod Spreads
Goldenrod spreads both vegetatively and by seed. Their rhizomatous roots form expanding colonies of clone plants. Spread is slow – around a foot per year. Once established, goldenrod patches are difficult to eliminate. Any root fragments left behind regrow into new plants.
Goldenrod seed production is prolific but uneven – some plants produce abundant seeds while others produce none. The seeds are very tiny and lightweight, dispersing readily by wind. Long-distance spread facilitates goldenrod’s colonization of new territories.
Certain species like Canada goldenrod (Solidago canadensis) and late goldenrod (Solidago gigantea) are more aggressive colonizers via rhizomes and seeds. But overall, goldenrod spreads at a moderate, manageable rate compared to notorious invasive exotics.
Is Goldenrod Dominant?
Invasive species are defined by their ability to establish dominance, displacing diverse native plant communities. Overall goldenrod exhibits only moderate dominance.
It thrives best in full sun and open areas with natural or human disturbances. Thus it colonizes roadsides, fields, clearings, and abandoned land. But goldenrod generally doesn’t take over intact, diverse plant ecosystems. And it doesn’t thrive in dense shade or areas with thick tree canopies.
While some species can form sizable single-species clumps, goldenrod doesn’t usually create monoculture stands that entirely eliminate competitors. It tends to integrate into mixed wildflower communities rather than displacing them entirely.
Benefits of Goldenrod
What harm does abundant goldenrod actually cause? It is extremely valuable ecologically:
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Provides copious nectar and pollen that support diverse pollinators like bees, butterflies, wasps, and flies.
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Host plant for moth and butterfly caterpillars.
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Seeds eaten by birds and small mammals.
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Forms protective cover for wildlife.
Compared to the ecological benefits, goldenrod’s drawbacks seem minor:
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Can crowd out pasture grasses and reduce yields in hay fields when overly abundant.
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Creates large biomass that takes time and effort to remove.
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Spreads rapidly into disturbed areas, sometimes unwanted.
Overall goldenrod’s advantages seem to outweigh its negative traits. From an ecological perspective, it is unfair to vilify this important native wildflower as an invasive pest.
Goldenrod Management
In areas where goldenrod growth needs controlling, management options include:
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Selectively removing plants by hand in early spring. Take care to dig out all roots to prevent regrowth.
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Cutting or mowing plants repeatedly during the growing season to stress them.
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Applying selective herbicides to foliage while avoiding harm to desirable plants.
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Replanting areas with competitive grasses and wildflowers. Diverse communities resist goldenrod encroachment.
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Preventing goldenrod going to seed reduces spread.
With some effort and persistence, goldenrod can be curtailed. But in natural areas, acceptance of goldenrod as an abundant native wildflower may be the wisest approach. This iconic fall-bloomer provides too many ecosystem services to be vilified as an invasive pest. Through ecological perspective and appropriate management, goldenrod’s spread can be kept in check while still valuing its vital contributions to nature’s web of life.
Cultivation and reverse rotary cutting
The most intensive methods had fluctuating effects on the goldenrod abundance and had also the smallest positive influence on diversity in these communities. In the first year, triticale cultivation on GW only caused a comparably low reduction of goldenrod by 58.5%. This poor management success could be explained by a combination of site exposition and unfavourable weather condition. The northern part of site is adjacent to a forest and is therefore more shaded and windless. Thus, humidity levels and consequently soil conditions were different to more southern parts of the site which are bright and open. Because of regular rain events until end of October 2016 (Table 3) cultivation had to be postponed again and again until beginning of November when soil conditions allowed a tractor access on the site. However, during sowing the northern part was subject to partly severe soil compactions caused by the tractor tyres as the soil conditions where more wet than in the other parts of the site. In addition, due to the late sowing a considerable number of triticale plants were not able to build up enough biomass before beginning of winter, consequently leading to partly lethal frost damages of the juvenile plants.
After the second triticale cultivation, which took place earlier and under more favourable soil conditions, the average number of goldenrod shoots decreased by −97.2%.
In contrast, reverse rotary cutting on GO had almost no effect on the goldenrod density. The milling caused not only an elimination of all plants (including potential competitors) but also a further fragmentation of the goldenrod rhizome. Because of the mild winter 2017/18 it can be assumed that the rhizomes were not severely affected by frost (Weber & Jakobs, 2004). Additionally, due to the outstanding cold, March 2018 (monthly average: 2.3 °C) germination and juvenile development of indigenous plant species was delayed. Consequently, native species had no initial advantage over the goldenrod. This was exacerbated by the sharp temperature increase in April 2018 (monthly average: 14.7 °C), which aligned the germination time of native plant species and goldenrod. Similar effects with high management intensities were obtained by Nagy et al. (2019). They emphasised that intensive disturbance regimes had negative impact on the already low diversity by consciously removing potential competitors, hence facilitating secondary invasion by goldenrod, as it was the case on GO.
The results of the study showed clearly that different management can contribute to effectively repress goldenrod stands in a nature conservation area. In particular, a short-term mowing treatment of three years can effectively reduce goldenrod density and simultaneously increase the establishment success of native species. Nevertheless, to improve species richness and community diversity a long-term approach is required as the management success of goldenrod in natural environments can be very sensitive to unpredictable factors like weather and wild animal disturbances. This is particularly true for nature conservation areas where management options are scarce due to legal regulations, strict planning schemes and restrictions in management guidelines. Therefore, we recommend a site-specific management plan which supports the effective reduction in abundance of goldenrod, but also has positive impact on species diversity, which contributes in the enhancement of community resistance against further invasions.
We would like to thank the operative project managers Franz-Josef Kovacs and Robert Knapp (both ÖBf AG) as well as the staff members of Experimental Farm Groß-Enzersdorf of University of Natural Resources and Life Science Vienna, in particular Susanne Stickler for her support and help during the field work.
The study was funded by the Austrian Federal Forests (ÖBf AG)—National Park Administration Donau-Auen, Orth an der Donau. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Rea Maria Hall1Institute of Agronomy, University of Natural Resources and Life Science Vienna, Tulln an der Donau, AustriaFind articles by
Received 2021 Dec 8; Accepted 2022 Mar 3; Collection date 2022. ©2022 Hall et al.
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
The late goldenrod (Soldiago gigantea Aiton; Asteraceae) is one of the most abundant invasive species in various types of habitats. Its long-creeping plagiotropic rhizomes enable the plant to build up dense, monospecific stands within a short time. Particularly in nature conservation areas, the invasion of goldenrod can cause severe disruptions in the naturally occuring mutualims between plants, insects and higher trophic levels, subsequently impeding the achievement of nature conservation goals. As management options of goldenrod in nature conservation areas are limited, this three-year study aimed to test the effectiveness of three management treatments (two-time mowing, triticale cultivation, and reverse rotary cutting) on four different sites in the Austrian Donau-Auen National Park. The number and height of goldenrod shoots were recorded three times a year on twelve permanent trial plots on each site to test for the effectiveness of the treatments. In addition, vegetation surveys were performed to observe the recovery potential of native plant species. Even though the three-years mowing and the triticale cultivation reduced goldenrod by 95.6% and 97.2% resp., we could find no relation between the effectiveness of the treatment and the intensity of disturbance created by the control option. On the contrary, with a reduction of only 5.4% in goldenrod density the most intensive treatment, the rotary cutting, showed the lowest efficiency. The highest positive effect on the re-establishment of native plant species was recorded with two mowing events per year. Even though the study revealed that certain management options have the potential to effectively reduce goldenrod and to simultaneously increase the establishment success of native species, results can only be seen as so-called snapshots. For example, as shown on site EJW one unforeseeable wild boar digging event transformed a 84.5% reduction into a 4.7% increase in goldenrod density. Therefore, a proper and regular monitoring is essential to be able to react to the effects of unpredictable events that can have severe impact on vegetation dynamics.
Keywords: Late goldenrod, Invasion in national parks, Management intensitiy, Biodiversity loss due to invasion, Mowing regimes, Rotary tillage, Land use change
Particularly in protected areas, these shifts in community structures due to alien invasion are a major concern of ecologist and natural conservationists. Even though numerous studies implied that these natural ecosystems are more resistant to invasion by alien species due to a high abundance of native species with a high degree of naturalness, most national parks are not isolated from surrounding landscapes. Rather they exist in a matrix of intensive human usage, and many types of human activity that could disturb the ecological resilience, enabling the invasion of alien species into protected areas (Pauchard & Alaback, 2004; Braun, Schindler & Essl, 2016; Foxcroft et al., 2017).
This is also true for the Austrian Donau-Auen National Park, which is part of the Marchfeld Plain, one of the most intensively used agricultural areas in Austria. Additionally, due to its location next to the border of Austria’s capital Vienna, the Donau-Auen National Park is a popular destination for thousands of cyclers, hikers and nature lovers throughout the year.
Until its foundation in 1996, also the area of the national park was under agriculture use and until today agriculture and particularly grassland management plays a vital role in the achievement of nature conservation goals. The Donau-Auen National Park comprises nine habitat types listed in the Fauna-Flora-Habitat Directive (92/43/EWG), including semi-natural dry grassland (habitat type 6210 Annex 1), sub-pannonic steppic grassland (habitat type 6240 Annex 1) and lowland hay meadows (habitat type 6510 Annex 1). To preserve these habitat types, protected meadows management concepts (i.e., mowing regimes) were developed to prevent these meadows from natural succession like scrub encroachment (Donau-Auen National Park, 2019). However, due to changes in legal regulations (i.e., the Austrian Agri-Environmental Programme “ÖPUL”), especially in the last 15 years, a couple of trade-offs in conservation and management goals evolved. For example, to ensure that ground-breeding birds can complete their breeding season without disturbance, mowing was not allowed before mid of August which indirectly promoted the establishment of goldenrod: After germination or sprouting goldenrod builds up biomass rapidly by intensive shoot elongation and leaf formation, leading also to the production of rhizomes within four weeks (Weber & Jakobs, 2004). To weaken the plant, it would be necessary to remove leaf area through an early cutting (plant height around 30 cm), in order to reduce the photosynthetic potential, leading to lower assimilation rates and thus, to a lower allocation of assimilates to the rhizome. In addition, for resprouting the plants have to remobilize assimilates from present rhizomes which causes a further attenuation of the plant (Szépligeti et al., 2018; Nagy et al., 2019). This shift in mowing regimes that neglected the morphological patterns of plant communities, finally led to an increasing number of monospecific stands of goldenrod, and subsequentely to a rapid decrease in native plant communities. Thus, in 2016 the management authority of Donau-Auen National Park—the Austrian Federal Forests (ÖBf)—started a three-years study in cooperation with the University of Natural Resources and Life Science Vienna.
Of particular interest was the development of a mowing regime, which was not only adjusted on the morphological development of goldenrod but also on the life cycle of native plant communties. In addition, the effectiveness of this mowing regime was tested under different site conditions (dry grassland, humid grassland and nutrient-rich grassland under intensive use). The background of these trials were numerous studies, implying the mowing is the only practiable management options in many conservation areas as (1) it does not represent a serious interference in the soil ecosystem, (2) it can be adapted to site-specific (nature conservation) goals, (3) it can contribute to increase biodiversity and ecosystem services, i.e., prevention of undesireable succession events, temporal adjustment to provide flowerage for wild bees etc. (Smart, Larson & Bauman, 2012; Pál et al., 2015; Szépligeti et al., 2018; Nagy et al., 2021).
An additional goal of the study was to test the efficiacy of other management options. Recently, a couple of studies showed how grazing, flooding or flaming can significantly decrease the abundance of competitive invaders like goldenrod (Le Bagousse-Pinguet, Gross & Straile, 2012; Szépligeti et al., 2017; Nagy et al., 2019; Coughlan et al., 2020). However, in nature conservation areas like the Donau-Auen National Park management options are scarce due to legal regulations, strict planning schemes and restrictions in the management guidelines. Therefore, the only two management options which could be implemented within this study was agricultural cultivation (triticale) and a reverse rotary cutting. Aside the fast aboveground growth of goldenrod, particularly its rhizomes gave a crucial advantage in the fierce competition for water and nutrients. Consequently, grassland mixtures and young trees were regularly prevented from establishment. As shown by Gala-Czekaj, Synowiec & Dabkowska (2021), intensive soil tillage and rotary cutting can effectively contribute in diminishing goldenrod stands by cutting and transferring the rhizoms to the soil surface where they can be negatively affected by different biotic and environmental factors. Thus, both treatments should bring a fast elimination of goldenrod in order to facilitate the establishment of grassland and young trees, respectively.
The Donau-Auen National Park extends from the north-eastern part of Vienna until the estuary of the river March at the national border of Slovakia. The total area comprises 9.300 ha, consisting of 65% alluvial forest, 20% water areas and 15% managed and unmanaged grassland. The utilization concept of these areas comply to three different zonings (Table 1).
| Zone | Management |
|---|---|
| Nature reserve zone | No landuse and no measures which would have impact on environment, landscape or ecological inventory |
| Temporary measures are only allowed if they support the natural development | |
| Nature reserve zone with management actions | In general, there are no measures taken, except they support the achievement of nature conservation aims (i.e., mowing of grassland to preserve biodiversity and/or habitats for valuable plant species) |
| Outer zones | All water ways and canals, touristic areas as well as cultivated areas (field) and buildings like administrative offices or flood protections dams |
Is Goldenrod An Invasive Species? – Biology For Everyone
FAQ
Is goldenrod native or invasive?
Though it is native to North America, Canada goldenrod is considered an invasive weed in Europe and Asia. Fun fact: Canada goldenrod can be used to create dyes.
Is goldenrod bad for the garden?
By planting goldenrods, you support late-season insect pollinators—bees, beetles, butterflies, moths, and wasps—that depend on it.
Is goldenrod beneficial to wildlife?
Goldenrod produces high-quality pollen, rich in protein, fats, and minerals, and is critical for migratory insects like the monarch butterfly. While goldenrod supports a wide variety of insects that forage on it while blooming, it also supports a variety of other animals throughout the year.
How do you stop goldenrod from spreading?
… together at waist height using twine or tape, and either Glyphosate (Roundup) or Triclopyr herbicide applied to the upper one foot of leaves on the stem …Nov 13, 2020
Is goldenrod an invasive species?
Thus, an invasive species is one that is an aggressive spreader. And though we have many native species that are aggressive spreaders – Canada Goldenrod (Solidago canadensis) comes to mind – these plants are not considered invasive because they fail to meet the first criterion of an invasive species – they are not introduced to the ecosystem.
Is goldenrod a weed?
Goldenrod (Solidago) encompasses about 150 species worldwide with approximately 60 species growing wild throughout eastern North America. Although they are often considered a weed or invasive wildflower, goldenrod can be grown in flowerbeds to add a brilliant splash of color in the fall.
Is Canada goldenrod an invasive alien weed?
13. Dong M., Lu J.Z., Zhang W.J., Chen J.K., Li B. Canada Goldenrod (Solidago canadensis): An Invasive Alien Weed Rapidly Spreading in China. J.
What is a Goldenrod plant?
Goldenrod has a high growth rate, and light, wind-dispersed seeds. It also changes soil properties by releasing chemical substances into the soil which impact on other plants. Goldenrod is a herbaceous plant that produces plumes of fluffy yellow flowers in the summer. It is native to North America, but has now spread well beyond.
Are there Goldenrods in a prairie plant community?
Apart from the hay fever myth, though, there are some prairie ecologists who are struggling with how to categorize and treat goldenrod in a prairie plant community. There are, of course, many species of goldenrod – including some very rare prairie and savanna species. Most people are fine with categorizing those as species in need of conservation.
Are goldenrods a species in need of conservation?
Most people are fine with categorizing those as species in need of conservation. I’m talking about some of the taller and more prolific/common species like Canada goldenrod and stiff goldenrod. Even Missouri goldenrod (which, ironically, is the state flower of Nebraska) gets occasionally thrown into the “down with goldenrod” conversation.