September Species Spotlight: Common Buckthorn and Goldenrod

September 30, 2022

Goldenrods of New York (Solidago spp.)

The low growing alpine goldenrod. C. Julia Goren, NY Natural Heritage Project

Tall goldenrod in a field. C. fotomem by Getty Images via CanvaPro

Goldenrods provide a bounty of color in New York state during the latter portion of the summer and the fall. There are 24 species of Goldenrod found in the state alone, but nationwide there are over 100! This great variety of species means that you can find goldenrod growing almost anywhere; like the top of mountains (alpine goldenrod), the Atlantic coast (seaside goldenrod), midwestern prairie (Missouri goldenrod) and even in your own backyard! They thrive in a variety of climates and soil types, existing in shifting sand dunes, bogs, forests and rocky summits.

Goldenrods belong to the family Asteraceae, with most of them in the genus Solidago. These plants come in a plethora of shapes and sizes. Some grow to an impressive 6 feet tall, and others top out at a mere 14 inches.

Monarch visiting goldenrod. Tina Nord, Pexels via CanvaPro

Goldenrod may produce hundreds of diminutive flowers which make up the flower head or inflorescence. All NY goldenrod species apart from silverrod produce flowers that are a deep vibrant yellow. These plants are a boon for pollinators and other wildlife, particularly monarch butterflies, which rely on the nectar as they begin their annual migratory journey. According to a study by entomologist Doug Tallamy, goldenrod flowers are visited by 115 butterfly and moth species, 11 bee species, as well as numerous beetles, caterpillars, flies & wasps! Additionally, the faded blooms of their seedheads provide nourishment for birds and small mammals well into the fall.

Certain types of goldenrod can be a wonderful addition to your native garden, displaying a burst of vibrant color as other garden plants begin to fade and providing crucial nutrients for pollinators. Some species of goldenrod are better for gardening than others, but check out your native plant nursery for varieties like showy goldenrod, stiff goldenrod or hairy goldenrod or ask what variety they recommend!

Common Buckthorn (Rhamnus cathartica)

A buckthorn infestation. Chris Evans, University of Illinois,

This deciduous shrub was first imported in the 19th century for use in landscaping, but as the time passed it was discovered that these fast growing, hardy trees were not content to stay where they were planted. Though the realization that this shrub is an aggressive spreader came fairly quickly, the damage was done and it has become established across much of New York and North America.

Common buckthorn is native to western Asia and the majority of Europe (with a few exceptions) where it grows naturally along roadsides, on exposed hills and is planted in hedgerows to form natural property barriers, or to serve as a windbreak. It prefers light shade but can grow in a wide variety of soil types – a highly adaptive trait which allows it to outcompete other native species which have more strict requirements for growth.

The leaves of buckthorn are 1 – 2.5 inch ovals. Paul Wray, Iowa State University,

Buckthorn is good for hedges in its native habitat because of its tendency to form dense thickets, it is this very same trait that makes it so damaging here. These tightly knit stands shade out the understory, displacing the low growing plants which would normally thrive there. This lack of understory growth has major effects, depriving wildlife of their normal sources of food and shelter and contributing greatly to erosion. The adaptability of this plant means that it is a threat to a variety of our precious native landscapes, like meadows, wetlands, and forests. Ideed, common buckthorn has established itself in most of the continental US.

This species has no natural or biological controls and also hosts two dangerous agricultural pests; oat crown rust fungus and the soybean aphid. Their bounteous production of seeds is spread by birds and other animals that eat their fruit, and the seeds themselves can remain viable in soil for up to 5 years.

Buck thorn’s thorn. Chris Evans, University of Illinois,

What can you do? Keep an eye out for invasive species like common buckthorn and report them using IMapInvasives – and make sure to eradicate them on your own property!

Common buckthorn can be identified by looking for the telltale “thorn” at the tips or forks of branches. For more information on how to identify this plant click here!




Goldenrod Resources:

Plant of the Month: Goldenrod


Common Buckthorn Resources:

Common buckthorn