Table of Contents for Giant Goldenrod (Solidago gigantea)
Giant Goldenrod (Solidago gigantea) is a herbaceous perennial that is found throughout the United States and Canada except for the western states and provinces. This plant, along with other goldenrods, is an important nectar source for many insects in the fall including the Monarch butterfly. It can grow from 3 to 7 feet tall and has lanceolate leaves with toothed margins. The golden yellow flowers bloom from August (sometimes July) to October and it is hardy in zones 3-8.
Taxonomy and Naming of Giant Goldenrod (Solidago gigantea)
Taxonomy
Giant Goldenrod (Solidago rugosa) was named by William Aiton, a Scottish botanist in 1789 in Hortus Kewensis based on a specimen in a garden in England. This species has kept the same name since. This plant is a member of the Aster Family (Asteraceae).
Synonyms
Over the years this species has had numerous synonyms applied to it. Below is a list of some of them as recognized by the Biota of North America Program (BONAP). Some of the various varieties and synonym species are based on location (Shinners 1953) with var. pitcheri.
- Solidago dumetorum
- Solidago serotinoides
- Solidago serotina
- Solidago xleiophallax
- Solidago pitcheri
- Aster latissimifolius
- Solidago gigantea var. serotinus
- Solidago gigantea var. pitcheri
- Solidago gigantea var. serotina
- Solidago gigantea var. shinnersii
- Solidago gigantea var. serotina
- Solidago gigantea var. leiophylla
Meaning of the Scientific and Common Names
Scientific Name
The genus name, Solidago, derives from the Latin words, Solidus and ago, which together mean to make (ago) whole (Solidus). The name comes from the medicinal uses of the plant. The species name, gigantea, derives from the Latin for giant, presumably in reference to its large size.
Common Names and Alternative Names
The common name as used in this post refers to the large size of this plant. However, this plant had a lot of common names that are in common use and it is hard to figure out which one is the most common since some are used about equally to others. Some of the names as also derive from the size such as tall goldenrod. Some others derive from the flowering time such as late goldenrod or early goldenrod. Another derives from the smooth stem of the plant.
Physical Description
- Plant Type: This plant is a herbaceous perennial.
- Height: 3 to 7 feet (1 – 2.25 m) tall.
- Leaves: The leaves are alternate, simple, toothed, and lanceolate to elliptic-lanceolate in shape. They are 2 to 7 inches in length and 0.5 to 2 inches in width.
- Stem: smooth, except slightly hairy in the flowers
- Flower color: golden/yellow
- Blooming period: August to October
- Fruiting type and period: achene — October to November
Range of Giant Goldenrod (Solidago gigantea) in the United States and Canada
This species is native to throughout the United States and Canada except for the west. It even extends into Mexico. It is considered to be rare in Florida. This goldenrod has been introduced in Europe and Asia.
Habitat
This goldenrod is grows in places where it is exposed to full sun such as fields, meadows, roadsides, shores, and edges.
Hosted Insects
This goldenrod supports the Wavy-lined Emerald (Synchlora aerata).
Other Supported Wildlife
Most goldenrods are major sources of nectar for a lot of insects in the fall. This goldenrod is no different. Insects that are helped the most include Andrena bees and bumblebees, but butterflies are also frequent visitors including Monarch butterflies. The leaves are enjoyed by leaf beetles (Illinois Wildflowers). Birds are fond of the fruits and it is deer resistant, most likely because of the rough stems.
Frequently Asked Questions
Is this plant poisonous?
The Celebrity Angels site lists Solidago, or goldenrods in general as being mildly poisonous to pets and the Deerfield Veterinary Clinic lists it as well. The Botanical Online site says that goldenrods are not poisonous, but that they can cause gastronomic distress if eaten.
How has this goldenrod been used?
This goldenrod has been used by Native American for cathartics and as a febrifuge (Native American Ethnobotany Database). It has also been used for fiber.
What other goldenrods are similar?
Solidago gigantea is part of the “Canada goldenrod” group of goldenrods, which can be hard to tell apart. However, this goldenrod can be separated by its characteristic smooth stems or lack of pubescence. Other members of this group, such as Solidago juncea and Solidago missourensis are about half as tall and have basal leaves, unlike this plant.
Is it invasive?
This goldenrod, though a native species, spreads easily via rhizomes and can display some invasive characteristics rapidly occupying nearby spaces through self-seeding. In Europe and in China, where it likely does not have other native competitors, it is quite invasive. Some spreading has been noticed in the McMullen House Bed & Breakfast gardens but it seems to be easily out-competed by the other goldenrods and asters.
Is it deer resistant?
Some websites show this plant as being deer resistant and this has been the experience at McMullen House. There are plenty of deer here, but they do not seem to bother this species of goldenrod.
Does goldenrod cause allergies or hay fever?
Goldenrods in general, which do not cause hayfever, are often confused for ragweed (Ambrosia sp.), which cause the common hayfever. These plants bloom at the same time, which may lead to the confusion.
Anything else interesting about this species?
This goldenrod is the state flower of Nebraska.
Gardening with Giant Goldenrod (Solidago gigantea)
Add Giant Goldenrod to your Garden
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Hardiness
This goldenrod is hardy in zones 3-8 and prefers open areas with full sun (can tolerate part shade) that have moist well-drained soil.
Optimal Conditions
This goldenrod prefers places that have full sun, but can handle some shade. Soils should be somewhat moist, but well-drained. This plant is known to transplant well and is easily spread by seed. It has an early blooming time from June to August and is one of the first goldenrods to flower.
References
- Shinners, L.H. 1953. Prairie variety of Solidago gigantea. Rhodora 55: 322-322.
