Canadian Goldenrod – A Complete Guide To Solidago canadensis

Canadian Goldenrod is one of the most prolific plants in North America (and the world). If you’ve ever driven along a rural road, abandoned field, or powerline cut in late Summer you’ve probably noticed the golden plumes swaying in the breeze. While this plant is gorgeous and valuable to wildlife, it is an absolute thug in the garden, and has become invasive around the world.

Nonetheless, I’ve written a complete profile of everything you need to know about Canadian Goldenrod, and even a bunch of things you didn’t know but should. Besides, this plant is actually really amazing when it comes to it’s ability to compete and crowd out other plants whether it is through seed, root, or chemicals secreted by the roots.

In this article:

• What is Canadian Goldenrod
• What are the benefits of Canadian Goldenrod
• Identification / Characteristics
• Is Goldenrod aggressive?
  • How to control Canadian Goldenrod
• How to grow and care for Canadian Goldenrod
  • How to grow Canadian Goldenrod from seed
• What Wildlife, Pests, and Diseases effect Canadian Goldenrod
• Where to buy Canadian Goldenrod
• Uses of Canadian Goldenrod
• Final thoughts

What is Canadian Goldenrod

Canadian Goldenrod, also known as Canada Goldenrod is a herbaceous perennial wildflower native to most of North America. Scientifically known as Solidago canadensis, it grows 4-5′ tall in full sun and well draining soil. Blooming yellow flowers for 4 weeks in summer/fall, numerous pollinators feed on nectar, pollen, and caterpillars on it’s leaves^[1][2][3].

There are a couple of confusing things when it comes to identifying Goldenrods….first, there are several species that look very similar to Canadian Goldenrod. Some examples of this would be Field Goldenrod (S. nemoralis), Yellowtop or Early Goldenrod (Solidago juncea), and Elm-leaved Goldenrod (S. ulmifolia)^[4]. These flowers all have similar inflorescence (form of the flowers), but really only Yellowtop is the most confusing in that it has similar aggressive tendencies. However all have characteristics that can readily differentiate them from Canadian Goldenrod. (Jump to identification)

Also, there are many other common names for Canadian Goldenrod, Solidago canadensis. Some examples would be Canada Goldenrod or Meadow Goldenrod. Further confusing the situation is that there are several different recognized varieties of the species ^[4], but for the purposes of this guide and simplicity, I’m going to only call it Canadian Goldenrod.

But I’ve got to be direct and upfront – Canadian Goldenrod is one of the most aggressive plants in the world. It is listed as noxious on multiple continents, listed as a threat to natural flora, and has even had state-sponsored campaigns advocating for it’s eradication in China^[5][6]. It can be difficult to control, but can be managed chemically over a few seasons or mechanically over long periods of time. (jump to control).

Within the native plant community there are frequent arguments and attempts to persuade people to grow Goldenrod in gardens because of the value they can provide to wildlife. While the benefits touted by these implorations are 100% true, the overly aggressive nature of Canada Goldenrod make it a difficult plant for one to have in a suburban or formal flowerbed setting. However there are less aggressive Goldenrod species (see Showy Goldenrod).

Native Range of Canadian Goldenrod

The native range of Canadian Goldenrod is nearly all of North America. It is present in every state except Louisiana, Alabama, Georgia, Florida, and South Carolina. It is present in almost every province of Canada except Nunavut^[1][2].

Canadian Goldenrod is invasive throughout the world

Canadian Goldenrod is not just aggressive in it’s home native-range….it has spread throughout the world. It has become firmly established in China, India and Europe, with large efforts aimed at it’s control^[5][6].

Reference Table

Scientific Name	Solidago Canadensis
Common Name(s)	Canadian Goldenrod, Canada Goldenrod, Meadow Goldenrod, Giant Goldenrod, Rough Goldenrod
Native Range, USDA Zone	North America, USDA Hardiness Zones 3-9
Bloom Time	Late summer / early Fall
Bloom Duration, Color	4 weeks, Yellow
Height	4-5′ tall (120-150 cm)
Spacing / Spread	3-4′
Light Requirements	Full sun to partial sun
Soil Types	Sandy loam to clay
Moisture	Slightly dry to moist, well-drained
Fauna Associations / Larval Hosts	Bees, butterflies / hosts numerous caterpillars

What are the pros and cons of Canadian Goldenrod

Pro

Wildlife

Canadian Goldenrod is an extremely important plant for wildlife. The amount of pollinator activity on the flowers is substantial, but dwarfed by it’s important as a host plant. Dozens of pollinator species lay their eggs on this plant, which in-turn feeds their caterpillars.

Beauty

Although generally thought of as a weed, the flowers of Canadian Goldenrod are incredibly beautiful when in peak bloom. Masses of the arching blooms swaying in the breeze make a gorgeous display.

Adaptable

There are not many plants that are as adaptable as Goldenrod. This plant can grow seemingly anywhere! If you wish to grow this plant, you probably can as long as you have a small patch of soil.

Cons

Aggressive

The adaptability of this plant is also a curse. The seeds of Canadian Goldenrod are carried by the wind and readily germinate in Spring on disturbed soil. And the rhizomes of Canada Goldenrod are incredibly aggressive and wide-spreading.

Plain foliage

Even when it looks it’s best, the foliage of Canadian Goldenrod is quite plain. But in times of drought or other stress can make the plant fairly unattractive.

Identification and Characteristics of Canadian Goldenrod

Identification of Canadian Goldenrod before blooming can be a bit challenging as there are several natural varieties that occur. So, take careful observation of the leaves in particular.

Stalk

The overall height of the stem to flowering stalk will grow 4-6′ tall with round arching stems that are smooth^[2][3][4].

Leaf

Leaves are alternate on the stalk, 2-5″ long by 1″ wide, and lanceolate to broad-linear in shape. The margins can vary form sharply serrated, to slightly serrated with small teeth^[3][4]. The upper side of leaves are medium green with small white hairs while the underside is smooth and light green^[2].

*Note – common Yellowtop (S. juncea) closely resembles Canadian Goldenrod. But it can be differentiated by bloom time and leaves. Yellowtop will generally bloom in mid to late summer (August in zone 6). But the key difference will be in the leaves, as Yellowtop will have small leaflets at the base of the leaves, while Canadian Goldenrod does not.

Flower

The top of the stem will produce multiple flowering stems as panicles with numerous small yellow flowers. Flowers are tiny, roughly 1/4″ (6 mm) diameter) and yellow in color^[2][3]][4].

Blooming generally lasts for 2-4 weeks in late summer to early Fall. About 1-2 months after blooming, seed heads will form will pollinated flowers were previously. These will be feathery and white, and quite attractive.

How to save seed from Goldenrod

Saving seed from Goldenrod is fairly easy. After blooming simply wait for 3-4 weeks for seed heads to form and mature. Once the seed heads are dry, white/gray and fluffy or feathery, they are ripe.

To harvest them, simply go out to a plant with ripe seed heads and bring a paper bag and pruning shears. Snip the stem below the seed heads while gripping the stalk with the other hand, thereby preventing it from falling when cut. Place the seed head into a large paper bag. Store this bag with seed heads somewhere cool and dry so it can further dry out.

About one week after drying the seed is ready for processing. You can scrape the seed off the seed head by using two fingers to straddle the flowering stalk, and stroking it off into a bowl or plate. Then, store the seed (with feather attached) in a zip-lock bag or envelope.

Root

The root system of Canadian Goldenrod is fibrous and rhizomatous, producing numerous spreading rhizomes. These ‘underground horizontal stems’ will spread far and wide^[2][8].

Is Goldenrod aggressive / invasive?

Native plants, within their native range cannot be considered invasive as they are supposed to be there. And within North America, Canadian Goldenrod is not invasive. It is however one of the most aggressive plants in the continent for colonizing new areas.

Research has shown that over long periods of time, other native plants will rise up and compete well with Canadian Goldenrod, preventing it from dominating an area^[9]. But all those abandoned farm fields and powerline cuts that are fairly ‘young’ ecologically….they tend to be dominated by Canadian Goldenrod.

Outside of a plants native range it can be considered invasive (hence it is invading lands it didn’t evolve within). It has become noxious outside of it’s native range in several continents including Europe, India and Asia^[5][7][10]. I personally observed roadsides in Sweden completely overrun with Goldenrod.

What makes Canadian Goldenrod aggressive

Goldenrod is extremely aggressive and competitive in three ways. First, by spreading through seed, second by vigorous and widespread rhizomes, and third by emitting allelopathic chemicals from the roots to suppress growth of surrounding plants. Let’s examine each of these spreading mechanisms more closely.

Canadian Golden spreading by seed

Each flowerhead from Canadian Goldenrod will produce hundreds to thousands of seeds^[9]. These seeds have a small feather attached to them that will help them travel via wind. This increases the range of the seed beyond just falling near the mother plant^[2][4]. Furthermore, these seeds germinate at very high rates in Spring in disturbed areas, making it an effective colonizer.

How Canadian Goldenrod spreads via rhizomes

As described in the identification section, Canadian Golden will produce abundant rhizomes that are far spreading^[4][8].

Plants that produce rhizomes generally do so in one of three ways.

1. They produce short clonal offshoots.
2. They are clump forming and spread radially each year.
3. They send out long suckering runners.
   • And this (no. 3) is what Canadian Goldenrod does, helping making this plant one of the most aggressive plants in the world.

These underwound rhizomes can go on for long distances from a single plant. I’ve personally pulled up 10-20′ sections. So a single mature specimen can send out these suckering runners in multiple directions, roughly 2″ deep, and send up sprouts where there is a bare spot in the soil.

I’ve often speculated how a rhizome determines exactly *where* it decides to send up a new shoot. My own hypothesis is that perhaps the rhizome can detect temperature changes in the soil. For instance, bare soil is probably a bit warmer than soil that is covered with a plant. But somehow it knows where it can put up new shoots, and take over any ‘open real-estate’.

Canadian Goldenrod and allelopathic chemicals

Allelopathy is a process by which some plants emit or secrete chemicals to the soil via their roots that directly benefit the plant by harming other organisms or plants. One of the most famous example of allelopathy would be the Black Walnut Tree secreting Juglone, which has been documented harming a number of other plants (particularly seedlings).

Canadian Goldenrod also has allelopathic chemicals secreted through the roots that has been documented harming other soil borne pathogens^[5], reducing seed germination and seedling size of other competing plants^[11] and also harming other plants^[6]. So, the roots from Goldenrod will suppress pathogens helping the plant survive, and they will also harm other competing plants (in the EU, for example), furthering their spread.

A further finding of recent research into Canadian Goldenrod and allelopathy has found that plants that have been growing for multiple generations outside of their native ranges have evolved to secrete more of these compounds than their native ancestors! Research in China tested the amounts of the allelopathic chemicals secreted and found that plants growing in China produced more allelopathic compounds than plants that had only grown in America^[12]. Thus, Solidago Canadensis plants in China that produce more of the chemical were rewarded with more offspring/spreading or dominating the native Chinese plants.

How to control Canadian Goldenrod

When it comes to controlling Canadian Goldenrod, there are several different approaches. You will likely use a combination of them over time. Given enough time, Goldenrod will reduce as other (taller) native plants establish. But this takes many years, so trying to either control it early in planting or by multi-year mowing in established areas is best.

Controlling Goldenrod where it is heavily established

If Canadian Goldenrod is overpowering your meadow or micro-prairie, you can reduce it’s numbers by doing a mowing treatment for a couple of years. Mow the entire meadow to roughly 6″ tall in late Spring, around June and again in August/September while the plant is in bloom.

The mowing in Spring is essentially performing a ‘Chelsea Chop‘, and will reduce the overall height of the plant. This allows younger natives to not be shaded out by the larger Goldenrod plants. The mowing while it is blooming will prevent it from setting seed.

Performing these June/September cuts for a couple of years will allow other plants to compete with Goldenrod, and eliminate it from being the dominant species.

Pulling isolated Goldenrod stems/rhizomes

When the ground is moist you can easily pull up Goldenrod stems as moist soil is easier to work. Then, with a garden fork or dandelion tool you can follow the rhizome and pry up the rest of the root as it trails throughout the plot. This method will need to be done several times a year, probably for 2-3 years.

I do this in my own micro-prairie every Spring. The new sprouts of Goldenrod are easily identified (see image below), and the moist Spring soil is very easy to work. I go tear it all up, pulling rhizome all the way.

Controlling Goldenrod with herbicide

Herbicide applications of Goldenrod are tricky, as it is hard to kill the Goldenrod plants while not harming other surrounding vegetation. And they really aren’t that practical for infestations of large areas unless you wish to kill everything. But Goldenrod can be killed with a broadleaf herbicide known as Triclopyr. Triclopyr is commonly sold as brush killer in hardware stores, and does not have a long half-life so won’t stick around in the soil very long^[13][14].

But to do this, mix up the brush killer following the instructions to the letter in a pump sprayer. It really helps if your pump sprayer is fitted with a small plastic dome that prevents overspray. Then, on a calm day go out and cut the Goldenrod stems with a hand pruners and gently spray the leaves and open wound of the plant.

Multiple applications will be required in order to treat Canadian Goldenrod with herbicide. I am not a fan of using herbicides on Goldenrod as the plant is very easy to pull in moist soil. So the harm done to other plants, or to insects that are incidentally sprayed or come in contact with the herbicide can be avoided by pulling. But, after repeated applications it can work.

Grow and Care for Canadian Goldenrod

Sunlight Requirements

Canadian Goldenrod will grow best in full sun, which is six hours of direct sunlight per day. But it can also tolerate partial sun, which is 4-6 hours of sunlight per day^[2][3]][4]. The more sun the plant receives, the taller and showier it will be.

Soil Requirements

For soil, Goldenrod can thrive in all but the sandiest of soils. Just make sure it drains well.

Moisture Requirements

For moisture, it will do well in slightly dry to moist soil, but is well-drained. In drier areas the lower leaves can turn yellow and fall off, which is common to many native plants^[2][4].

Maintenance

Cutting seed heads of Canadian Goldenrod BEFORE they mature can help reduce the spread by self-seedings. And planting it inside of a large pot with drain holes and lined with landscape fabric can help slow the spread (but probably not eliminate it).

For maintenance, Canadian Goldenrod can sometimes benefit aesthetically from the Chelsea Chop in spring, as this keeps it from leaning too much.

Also, if you are trying to keep this species in a confined location…..good luck! It will spread very aggressively from self-seeding or rhizomes. Pulling unwanted plants may become a chore unless you resign yourself to allowing the spread.

Fertilizer

Canadian Goldenrod will not requite any supplemental fertilizer. Applying high-nitrogen fertilizers may make the plant flop over.

How to Grow Canadian Goldenrod from Seed

Canadian Goldenrod is fairly easy to grow from seed. Although it can be a bit confusing as I’ve found references stating both that cold stratification is and is not required to break dormancy^[2].

However, recent research out of Poland has confirmed that it is not needed, as they conducted trials under several different stratification regimens (-18C, 4C, 25C) and found that cold stratification did not have a significant effect on the overall germination rate or time^[15]. Still though, the tiny seeds should be surface sown, as they need exposure to UV radiation to germinate.

I should also note that if you are already planning on winter sowing seed, you can easily Winter Sow Canadian Goldenrod at the same time. The cold temperatures will not harm it in any way, and you will also have your seeds germinate earlier than if you just scattered them on the soil.

Process to germinate Canadian Goldenrod seed

The following steps are to

1. Fill a suitable container with moist potting soil. The soil should be moist enough so that when you squeeze a handful, only a few drops of water will fall out of it.
2. Scatter Canada Goldenrod seed on top of the soil
3. Mist the soil/seed again using a spray bottle or pump sprayer so you don’t wash the seed away.
4. Place the container in a location that receives morning sun and afternoon shade
5. Water the container in the mornings using a pump sprayer or spray bottle by misting the seed. Pick up the container to feel the weight and make sure it is moist enough.
6. Germination should occur within a few weeks.

Establishment

Canadian Goldenrod seedlings can be planted to their final location once they show 2-3 sets of true leaves. The young plants should be protected from deer and rabbit browsing. This can be done by applying Liquid Fence per the directions (and frequency) or using a cage/fence.

Direct sowing Canadian Goldenrod

Canadian Goldenrod seed can be direct sown in Fall. Simply scatter the seed over a disturbed area, and walk on it to press it in to the soil. Try not to cover the seed, as it needs exposure to light to germinate. Seed should germinate in early Spring.

Wildlife, Pests, and Diseases associated with Canadian Goldenrod

Pollinators

Canadian Goldenrod is an incredibly important plant for pollinators. Over 200 different species of pollinator have been documented visiting it including long-tongue bees, short-tongue bees, pollinating flies, wasps, moths, beetles, and butterflies. Furthermore over 40 species of moth caterpillars are hosted by Canadian Goldenrod^{[16][17][18][19]}.

The abundance of Canada Goldenrod is truly important for some of our selective pollinators. Goldenrod is believed to be a preferred food source for oliogolectic (discerning in their pollen selection) bees and pollen eating beetles^[2].

And finally, there are a wide variety of gall forming insects that utilize Canadian Goldenrod^[20].

Birds

Various birds will eat the seeds including the Eastern Goldfinch, Prairie Chicken, and Swamp Sparrow^[2].

Livestock / forage

Canadian Goldenrod can be eaten by cattle & sheep and is considered of average forage value^[2].

Deer and Rabbits

Both deer and rabbits will eat the foliage, particularly when it is new growth^[2]. Once the plant ages they will not browse it so much, as it isn’t preferred.

Disease

In general Canadian Goldenrod isn’t effected by disease. It will occasionally get powdery mildew or rust, but the effects are only cosmetic and not fatal^[19].

Canadian Goldenrod leaves turning yellow

The lower leaves of Canadian Goldenrod may turn yellow as the plant matures or in times of drought. These yellow leaves will often eventually fall off. This is a normal response, and as long as it is just the lower leaves, should be considered normal.

Where you can buy Canadian Goldenrod

Canadian Goldenrod is not typically sold in nurseries, as it isn’t a typical ‘garden friendly’ plant. But it can be purchased at specialty nurseries that deal in Native Plants. You can find native plant nurseries near you on our interactive map.

Where to buy seeds

We have ordered a variety of native flower seeds from Everwilde Farms, which you can order right from Amazon through our link on our RECOMMENDED PRODUCTS PAGE. (We may earn a small commission when you purchase through our links, at no cost to you. This helps support our website.)

Uses of Canadian Goldenrod

Garden Uses

It may be possible to use Canadian Goldenrod in a formal garden setting, but I personally would never add this plant to a flowerbed. It is just too aggressive.

You can probably contain the rhizomes, or slow them down if planted in a pot lined with landscape fabric (see how to stop plants spreading here). I have had this method both stop aggressive plants (looking at you H. strumous) and fail (well hello Obedient Plant and Beebalm).

It could certainly be added to an established meadow or micro-prairie, but care would have to be taken to keep it in check. Particularly pulling unwanted rhizome sprouts each Spring.

I do have this plant in my wildflower gardens, but not by choice. If you live within it’s native range, it is likely that you will encounter it at some point. That being said, I try to control it each year by pulling, and it is never enough, as new plants sprout up from rhizomes at the edge of the woods or further beyond.

Companion Plants

Canadian Goldenrod is quite aggressive, but in a meadow setting can look great. It should be planted near plants that can reach several feet tall in order to compete effectively with it. Some good choices include the following;

• Black Eyed Susan
• Brown Eyed Susan
• False Sunflower
• Gray-headed Coneflower
• Little Bluestem or Big Bluestem
• New England Aster
• Prairie Blazing Star or Meadow Blazing Star
• Sawtooth Sunflower
• Spotted Beebalm
• Tall Sunflower
• Wild Sunflower

Revegetation and reclamation

Because of it’s aggressive nature and toughness, Canada Goldenrod can be used for rewilding disturbed areas, reclamation of mine spoils, and erosion control^[2][19].

Medicinal Uses

Canadian Goldenrod has been used medicinally by the Native Americans for hundreds to thousands of years. More recently a decoction (tea) has been frequently used in Europe to tread kidney stones^[21]. Research has also found it to be an effective pain reliever in mice, as well as antibacterial^[22].

Native American uses of Canadian Goldenrod

There were 29 medicinal uses of Canada Goldenrod documented for nine Native American Tribes^[23]. Some of the uses of the plant include the following:

• A decoction of the plant was used in a bath as a sedative to calm crying babies or with excessive diarrhea
• The flowers when crushed and chewed could relieve a sore throat
• Infusion of flowers used as a pain reliever
• An infusion of flowers or shoots could also be used to treat fever
• The roots could be smoked like tobacco
• Infusion of roots could be used to cause vomiting

Final Thoughts

Canadian Goldenrod is a beautiful native plant that is extremely valuable to pollinators and insects, and thus the greater food chain. It also is one of the most aggressive plants on the planet and has successfully colonized several continents.

If you happen to be in a native plant forum and mention that you want to get rid of Canadian Goldenrod, it is likely that you may be shamed by some people for not keeping it because of it’s benefits to pollinators. The benefits that these online commenters are touting are all true.

The thing is, Canadian Goldenrod self-seeds and pushes itself everywhere via rhizomes, making it one of the most aggressive plants around. Compound this difficulty with how frequently one encounters Canada Goldenrod in every ditch, abandoned lot, or unattended patch of ground, and I’m inclined to conclude that Canadian Goldenrod is doing just fine without it being in my flower beds (even though it is there, in the back, in the micro-prairie).

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