Plants Invading Patapsco


The colors of Spring are always a welcome sight after months of dull greys and browns throughout the Patapsco valley.  Shades of greens and bright pinks dot the branches as our favorite trees begin to fill out again.  As exciting as these changes are, some of them only appear to be the regrowth of our native forest.  Many examples of early blooms and spring growth are actually invasive plants that spread throughout native forests and threaten to disrupt the native ecosystem.

Invasive plants are species of plants introduced to local areas from foreign ecosystems, often Europe or Asia, that pose a threat to native ecosystems.  This threat can manifest itself in a variety of ways.  Perhaps the most common form is unchecked growth by the invasive due to a lack of predators.  These plants can see explosive growth because unlike their native counterparts, no local animals eat them and keep their numbers in check.  Before long they have monopolized the available resources such as space and sunlight and force out any remaining native competitors.

Here are some examples of these plant invaders that are common in the Patapsco Valley:


This shrub is easily identified by its reddish fuzzy stem and bright green leaves.  Often found along trails and in patches, this plant produces berries in the summer and will spread if allowed to.

English Ivy:

This vine is rampant throughout the Patapsco, found both in developed and wooded areas.  Often planted for aesthetic reasons or in gardens, english ivy grows quickly and will climb tree in search of sunlight.  As the plant grows it will cover and eventually smother its host tree, making it a serious threat to even our most established forests.

Lesser Celandine:

This is often found as a short ground cover in the understory of the Patapsco and throughout small patches of earth in developed areas.  Celandine spread quickly and can give an area the appearance of having a “green carpet” as it covers the forest floor.

Japanese Barberry:

This shrub has a woody stem and small, bright green leaves that turn red over time.  It is also covered in long skinny thorns about a half inch in length, making removal or even just touching this shrub painful.  Barberry has numerous negative impacts on our ecosystem, including increasing local tick populations!  Barberry is so impassible by larger predators (owls, hawks, and foxes)  that is provides an unusually safe home for rodents.  As the rodent population grows and congregates under these shrubs they support more ticks and eventually increase the spread of lyme disease!

For more information on invasive plants, click here!

Highlighted Trail: Mill Race Trail


The Mill Race Trail might be the most scenic trail in the whole Patapsco Valley.  The trailhead is located in Oella, near the Oella Mill building.  True to its name, this trail follows what was once a mill race along the Patapsco.  A mill race is a channel cut to provide a steady current of water to turn a mill wheel.  This leaves a very steady flat trail, especially for Patapsco, along a picturesque raised path. The trail connects Oella to numerous trials in the Pickall area of PVSP, several of which are featured in our Cold Weather Hiking Post, which can allow for hikes in and out of PVSP to also connect with Historic Ellicott City and all the town has to offer.

Trail Map:

Elevation Profile:

Trail Photos: