Wednesday, September 28, 2016

Goldenrod Safari

A Goldenrod patch at my home

     This time of year, many people notice how abundant goldenrods are in our open areas. Since this coincides with many people getting hay fever allergies, they wrongfully blame the goldenrods they notice, rather than the ragweed and other real culprits that they don't. Showy flowers such as goldenrods have larger and heavier pollen that is transferred by pollinators such as insects. Wind pollinated plants do not need showy flowers since they need not attract any pollinators, but need to produce an abundance of light weight pollen in the hopes some of it is carried onto another flower. Those plants, especially ragweeds, are what cause the issues this time of year.
     Goldenrods are an important and abundant Fall flower. Many animals depend on them. We have close to 50 species in Virginia alone, so they're adapted to many growing conditions, but most favor open, sunny locations. Due to their adaptability and showiness, many goldenrods are garden staples, both here and in other countries. In some parts of the world however, due to their adaptability, North American goldenrods have the potential to become invasive. They have some allelopathic traits, exuding chemicals that inhibit the growth of certain plants (such as maples) that also help them compete.
     The Genus name "Solidago" translates to "making whole" and points to worldwide use of this plant group for many medical and other uses. In  North America, famed ethnobotanist Daniel Moerman listed too many uses by native peoples to cover here. I will mention just a few for one of the most common species, Solidago canadensis, Canada Goldenrod though: The Iroquois used it for such various things as treating body pains, using the roots as an emetic to induce vomiting, and even to assist in getting better luck, deeming it "gambling medicine" as did the Navajo. The Potawatami used the blossoms for dealing with fevers. The Zunis chewed the flowers when they wanted rid themselves of a sore throat. The Shuswap believed a bath made from goldenrods could assist a mother at childbirth. The Meskwaki believed it could be used as wash for children who did not talk or laugh. The Thompson used it for everything from treating diarrhea, to using it in steam baths for treating paralysis and cripples, to using it to treat cuts and sores on their horses.
     Francis Porcher, a Confederate doctor charged with finding local sources for medicines no longer available during the Civil War, also found uses for it. He wrote that it could be used for cordage, making usable rope. He also said it made for a medicinal tea and a valuable dye.
     In Europe, their species had long been used. According to folklorist Jack Sanders, it was greatly revered. He noted that herbalist Nicholas Culpeper called it a "sovereign wound-herb, inferior to none" and that English herbalist Donald Law deemed it "as much a panacea as any plant could be." More fanciful uses were attributed to it by diviners and witches. 
     Thomas Edison was a big believer in goldenrod use. He experimented and succeeded in making rubber from certain Solidagos. He even bred his own type that grew to twelve feet tall to maximize the rubber compounds. Henry Ford even gave him a Model T with tires made from his goldenrod rubber. 

European Honeybees make great use of goldenrods this time of year, benefiting us with honey.

     Of course, it is wildlife that have the most uses for goldenrods. In addition to feeding on the many insects that use Solidagos (see below), birds such as goldfinches, juncos, pine siskins, trukey, indigo buntings, and various sparrows all feed on the seeds. Despite the chemicals in them that made them such sought after medicinal plants, mammals such as rabbits, voles, mice, beaver, muskrat, groundhogs and deer (although others consider it deer resistant) all make use of it.
     Insects make the most use of them (and feed such things as birds and bats in the process). A study in 1996 found 103 species that fed extensively on Tall Goldenrod (Solidago altissima), while another on Canada Goldenrod (Solidago canadensis) in 1948 collected 241 insects on it over a year. Over 13 species of grasshoppers favor them, as do 16 bug species, 9 aphids, 7 leaf hoppers, and countless beetles (including 15 leaf beetles). Caterpillars numbering 115 different species have been documented feeding on goldenrods (and which then of course become the main prey of birds and bats). Tons of pollinators visit the flowers, including 7 bee species that are oligolectic, requiring that specific pollen in order to be able to reproduce. One species for example, Andrena solidaginis, even has Solidago as part of its name to show how necessary it is for its survival. There are several galls that are particular to goldenrods also. These in turn have certain resident and parasites that will also live in them.

Goldenrod Bunch Galls are caused by a specific gall midge, the Cecidomyd midge Rhopalomya solidagnis. Note that its scientific name contains the genus Solidago, showing how they live no where else.
The Goldenrod Round Gall is caused by the tephritid fly Eurosta solidagnis, in our area usually restricted to either Tall or Canada Goldenrods. One of these has been raided and now has a hole in it, likely helping to feed a chickadee or downy woodpecker over the winter.
Elliptical Goldenrod Galls are formed by 2 kinds of moths. This one is  open and so may have emerged already.

     As you can see, goldenrods are extremely valuable plants and deserve to be included in our gardens and landscapes, not simply because of their beauty and adaptability, but for the wonderful wildlife value they have. There was even a movement to make goldenrod our national flower in the late 1800's. It has had to settle for being the state flower of both Kentucky and Nebraska, and the state wildflower of South Carolina. 
     I thought that to show you just how much wildlife like them, I'd take you on a short "Goldenrod Safari" showing just a small portion of the common things you can find making use of a goldenrod meadow, especially this time of year. So enjoy:

Long-horned Locust Borer beetles, yellowjacket mimics, love goldenrod. They eat the pollen, pollinating it at the same time. They often kill 2 birds with one stone, mating while feeding on the goldenrod.
Daytime flying Ailanthus Webworm Moths are often found nectaring on Goldenrods.  More on them here:
Migrating Monarch and Buckeye Butterflies (such as this one) find goldenrod blooms to be life savers on their travels.
Several very similar looking wasp mimic moths are commonly found sipping nectar on goldenrods, such as this Yellow-collared Scape Moth.
Numerous Syrphid or Flower Flies favor goldenrods, most being excellent bee and yellowjacket mimics.
Bees love goldenrods, like this bumblebee and its larger carpenter bee cousin.

     So the next time you pass a Goldenrod patch, do more than smell the flowers (though you can at least do so with out fear of allergies). Stop by and conduct a little safari, trying to see how many different animals are using them. 


  1. Alonso, this is an amazing post. I had no idea so many "critters" depended on goldenrod. I had no idea it was used extensively as a medicinal. And I learned a new word: oligolectic! Very cool. We have some Canada Goldenrod at the Library Garden, but its extensive runners tend to make me dislike it. Do any of the cultivars have anywhere near the wildlife value? We have two stands of the cultivar "Fireworks." Thanks for your invaluable posts sharing your deep knowledge of the interconnected web of all our "relations!" Warmly, Judy

  2. Our native Solidago caesia is a very well-behaved and attractive clumping goldenrod for landscaping. It likes some shade. Solidago nemoralis (gray goldenrod) is also pretty well behaved. They are both much shorter than Canada goldenrod and the very lovely "Fireworks."

  3. We have so many goldenrod choices, that it is not really necessary to go for a cultivar I don't think. Canada and Tall (and Roughstem among others) can spread. This is especially true if the flower is altered in some way so as to perhaps affect what pollinators it attracts. I also find that cutting them back around July 4th still allows them time to recover and bloom, but makes them much shorter and less prone to falling over. Thanks.