Canada Goldenrod Invasion
February 16, 2010 by Bill
Filed under Customer FAQ's, Species and Product Overview
This question has come up occasionally from various customers so I thought I would pass on my response:
A customer asks: “We have an invasion of Canada Goldenrod in our prairie and I’m wondering if there is a parasitic plant that we can add to the prairie to control this?” Also, in a couple of new prairies that we have seen where seed has been purchased and planted, the Canada Goldenrod is right there. Is there a possibility that this Goldenrod seed is in the seed we are buying? What can we do about it?”
I answered:
Canada Goldenrod (Solidago Canadensis) is basically a native weed. It was one of the main perennials to colonize naturally disturbed areas such as buffalo wallows. Now we have plenty of other non-native species that also fill that niche. It is a “relatively” short-lived species that is mostly gone after 20 years. Of course that is way too long for us or our customers. Some native seed nurseries actually sell this stuff! Whenever I have been asked about it I always tell people that it will show up whether they want it or not.
Because most of North America is now being disturbed on a regular basis, you find this growing everywhere. Every fall, the very small winged seeds are distributed by the wind. When you work up an area it is already in the seed bank.
There is a black caterpillar that feeds heavily on this plant but I do not know the name of it. On certain years I have seen larger colonies stripped bare of leaves. With regard to parasitic plants, I do not know of anything that would control it specifically. A diverse native mix is probably your best bet. We have been experimenting with treating individual plants with heavier concentrations of Round-Up. Ideally the chemical will be trans-located into the roots and wipe out larger portions of the colony.
Canada Goldenrod flower
Canada Goldenrod leaf and stem
I find it impossible to believe, that after 20 years, Canada Goldenrod will be gone from a prairie planting. After all, it produces seeds every year plus spreading by rhizomes. I sincerely hope I am wrong, but…….
Thank you for your blog, and the discussion of Canada goldenrod. I have had a problem with this aggressive plant in my wooded area, and more recently, in prairie gardens which were planted primarily with seed from your company. I agree that the plant is everywhere! Perhaps a more thorough discussion of control techniques would give your readers more reason for optimism??? After consulting with experts, the population in the wooded area was brought under control by a combination of techniques – some were pulled, (although this does present the possibility that desirable adjacent plants might be damaged, and the soil disturbed), plants that were getting too close to going to seed had their seed heads removed, and many were herbicided. Attacking the plants for one year isn’t enough – you have to stay vigilant, and remove any new plants that show up. Getting rid of the flowering heads so they can’t go to seed is one way of helping to prevent the plant from spreading. But, it won’t deal with the rhizomatous nature of the plant.
Once Canada Goldenrod is entrenched, expecting it to run its course in any reasonable time frame is being hopeful! The best method for eliminating individual plants is the “glove of death.” Put on a rubber glove and then put a cloth glove over that. Saturate the palm of the cloth glove with herbicide and grab each Goldenrod stem and saturate the plant. This should eliminate that particular stem and hopefully part of the root mass. Since the underground rhizomatous mat will re-sprout, this will be an ongoing project but eventually you should be able to get ahead of it. It may be impossible to eliminate this species from an area, but once it has good diverse competition and it is not a major player, it will be under control.
The question of which herbicide to use may be best left to the herbicide experts. The herbicide market is much like the pharmaceutical industry in that there are always new, better formulations. I would suggest using the most effective product since it is such an unpleasant, time-consuming process to apply.
I do want to point out from the original post that there are many assurances that the Goldenrod seed did not come from us. There are some prairie seed companies that will use a combine to collect multiple species from an area and sell the mix of combined seed as a prairie mix. If there is any Canada Goldenrod in the field it is reasonable to expect that it will then be in the seed. I am sure a reputable dealer would make assurances that there is no Canada Goldenrod in the field before combining the seed. Prairie Moon harvests each species separately and has each species tested for purity. When our seed mixes are put together, each individual species is measured out.
I can’t believe my eyes! Goldenrod is one of the most valuable plants on the continent to feed our pollinators. Its high protein pollen and tremendous nectar yields give many species of bees and wasps their last good feed of the season. Each plant is host for an entire community of living things, as as such, is a great promoter of biodiversity.
At the same time, it is threatened by the oft-repeated, but false claim that it causes allergies. Ragweed is the allergy culprit. To get the heavy, sticky goldenrod pollen in your nasal passages, you’d have to stuff a flower up your nose.
Please, please protect goldenrod wherever it occurs. We don’t want to lose a valuable native plant due to misinformation.
Dave Green
(The Old Drone)
Thanks to Dave for pointing out the important role that Goldenrod (Solidago) species play. They certainly are an important plant in terms of pollinators and they have been wrongly blamed for allergies. My concern with the Canada Goldenrod is that it’s aggressive nature tends to limit the diversity by out-competing the other native species. I doubt that it is possible (or desirable) to completely eliminate it from a mixed planting. Pollinators will do best with a diverse planting and Prairie Moon lists 11 other Goldenrods.
No plants do more to support our native pollinators than goldenrods. They provide that last burst of food that are essential for all who live over the winter. You really must hate nature if you want to get rid of them!
They won’t ‘vanish’ after 20 years of non-disturbance of a site, but they WILL return to balance with the hundred other meadow species that will be there by then.
I don’t think that a person who tries to control one species of vegetation in an effort to give an advantage to another species necessarily hates nature. Some people “love” nature better when it looks a certain way. This may seem wrong in some eyes. It also seems an allowable conception when one considers the many other vegetation controls that are employed for strictly aesthetic reasons that have a very different end. Mowing for instance is usually done for aesthetic reasons and usually leaves no species for pollinators to enjoy.
When some people plant an ecosystem, they are hoping for something that looks markedly different from the low diversity fallow fields that are so ubiquitous in the landscape. They are usually hoping for a diverse number of native species which will not only look good, but also function as an ecosystem. Everyone has a different approach to the aesthetics of a planting. We actually advocate a diversity of goldenrods (notice our seed mix species lists and the diversity of goldenrod species in our catalog.) The fact of the matter is that the Canada Goldenrod is so present in the current landscape that a number of people have taken to wanting to limit its numbers in their planting in hopes of giving other species a better chance. To these people the Canada Goldenrod looks weedy.
Trying to limit a fairly aggressive species in the early years of a planting can make sense. Once the other species have come to maturity the Canada Goldenrod should not be as much of a problem because it will be kept in check by the other species. If there are no aesthetic goals for a planting, letting one species dominate for a time is probably just fine.
Hi Folks
I have been doing prairie restoration since 1993 and have found that seeding a high diversity prairie is key to maintaining a prairie with balance. In rich soil I may still have a problem with Canada Goldenrod but if you start with a high diversity mix, it will thin out over time.
My wife’s grandmother gave us Christmas tree ornaments made from the pods of common milkweed many years ago. They were treated with red velvet,trimmed with small beads on the edges and had a little figurine in the center. They are adored by everyone. Making these are a great way to engage kids into the natural world by integrating nature with art.
Thanks for the additional feedback on Canada Goldenrod Ron. It’s always a concern of many customers, as you know, so you agreeing with us that a diverse seed mix is the key will help many that read this.
I can just imagine those Christmas ornaments! I’m going to post that comment in the ‘JUST Common Milkweed?’ blog too if you don’t mind…
I remember my parents had Christmas ornaments they brought back from Mexico in the 1970′s (before it was ‘touristy’). These ornaments were made out of nutshells and a complete nativity scene was inside made with natural fibers (grasses, etc.). I would spend hours playing with them each Christmas.