Natural Shore Technologies |  612-703-7581 
March Article
Be on the Lookout: Three New Non-native Plants Invade Minnesota

Could it actually be that the groundhog was a bit off this year? We hit 62 degrees in the Twin Cities the other day, a tornado touched down, and ice sheets are quickly disappearing off of our local lakes. Is it possible that spring will be arriving quite early to Minnesota, in spite of the behavior of our furry animal indicator?

Open water at Birch Lake

In the blink of an eye, we will have our stark brown landscape quickly turning to a lush carpet of green. So, let's take a closer look at our landscape and the "native" and "non-native" plants that make up this community. What we call "native" species are those plants that historically occurred in a given region or habitat prior to European settlement. Invasive "non-native" species are the troublemakers.  They are brought into a region that they did not historically populate and run wild, causing environmental and economic loss. A "weed" is a more generic term for a plant that is simply growing where it is not wanted. Weeds can be native or non-native plants.

Those invasive troublemaker species are popping up in Minnesota all the time.  Here are three invasive non-native species to be on the lookout this season: Oriental bittersweet, black swallow-wort and Grecian foxglove.  New to our state, these weeds currently have limited, localized infestations.  If promptly controlled, their establishment may be curtailed and their detriment to our environment prevented!

© 2010 K. Chayka
Perhaps you are familiar with native American bittersweet ( Celastrus scandens )?  But are you aware of Oriental bittersweet ( Celastrus orbiculatus ), an invasive non-native look-a-like?Oriental bittersweet was introduced to the Eastern U.S. in the mid-1800s as an ornamental.  It is a perennial climbing vine, developing a thick (4-inch diameter), woody stem capable of quickly growing to a length of 60 feet.  This vine often smothers surrounding vegetation and  can  even topple small trees.  It flowers along the length of the vine, which produces an abundance of seed.

This highly invasive species has steadily spread west and south since its introduction.  Attracted to the abundant fruit, birds gobble up the tasty treats, and freely disperse seed in their droppings.  Oriental bittersweet was commonly planted as an ornamental and its berries were widely used in decorative arrangements and wreaths, furthering its distribution.  These practices are now against the law in Minnesota.

Both bittersweet species are similar in appearance, however, there are a few distinguishing identifiers.  Oriental bittersweet produces fruiting structures with yellow sheaths, in the leaf axils along the entire length of the vine, whereas, American bittersweet only produces orange sheathed fruit clusters at the terminal end of the vine.  

2010  © Peter M. Dziuk

Another invasive species to watch for is black swallow-wort, Cynanchum louiseae.  Commonly referred to as 'climbing milkweed' or 'Black Dog-strangling Vine', black swallow-wort is a European species.  Actually a member of the milkweed family, this species is NOT beneficial to the reproductive cycle of monarch butterflies.  Studies have shown monarch adults will lay eggs on this milkweed, however, the caterpillar larvae cannot use this species as food and subsequently die.
2002  © Peter M. Dziuk

Black swallow-wort is a perennial vine growing up to six feet in length, typically occurring in dense patches, smothering and suppressing native vegetation.  Flowers are purple, and the seed is formed in milkweed pods in late summer.
2001  © Peter M. Dziuk

Infestations are not normally discovered until the vine has become well established.  This species sprouts readily from its root system, forming dense thickets which can choke out native vegetation. 
© 2002 Peter M. Dziuk

Lastly, Grecian foxglove,  Digitalis lanata , is another invasive non-native species to look out for, but do not touch this plant!  This invasive contains compounds that are dangerous to humans and livestock and should not be touched or ingested.
© 2010 K. Chayka
Grecian foxglove was brought to the states from Europe as an ornamental, and eventually escaped cultivation.  Prone to forming large stands, this plant is aggressively displacing native prairie and savanna species where it becomes established.
2010 © Peter M. Dziuk

In Minnesota, Grecian foxglove is a biennial, forming a rosette in the first growing season. During the second year, this invasive species grows rapidly, forming a flowering stalk with distinctive clusters of hairy, cream, tubular flowers containing purple/brown veins.
Grecian foxglove spreads exclusively by the copious amount of seed it produces.  Each seed pod has a small hook which easily attaches to animal fur or human clothing, thus facilitating the spread of the species.

New invasive species are a continual problem, but preventing their establishment is a real possibility.  Be on the lookout for these non-native invaders to help preserve our Minnesota ecosystems.

Our well-trained maintenance crew can help you monitor your natural areas for invasive species. We use the most up-to-date treatment methods to control these and other non-native invasive plant species.  Please call us today to discuss your monitoring and maintenance needs!
Photo Caption Contest of the Month *New!*
Caption our Photo and Win Prizes!

Our greenhouse is up and running for the 2017 season and our first visitor needs a photo caption!

Visit and "Like" our Facebook Page Here!

Then add your caption to this photo and you could win!

$25 Gift Certificate for Native Plants! 

It's that easy! And check back next month for another  photo  caption contest!

February's Caption Contest Winner:

"Ok, I'll count to 10 and THEN you're in trouble."- Tammie K.
Native Plant of the Month
Prairie Smoke     
Prairie Smoke Natural Shore TechnologiesGeum triflorum      

Moisture: Moist or Dry
Exposure:  Full Sun or Partial Shade  
Blooms: April-June
Color: Pinkish Red 
Height: 0.5-1 Feet
Prairie Smoke is a short, hairy plant up to 1 foot tall that grows and spreads from rhizomes. They have  hairy b asal leaves and nodding red-pink flowers that are arranged 3 flowers per stalk.  After fertilization the flowers turn upwards and develop plumes.  Showy fruits have clusters of rosy plumes attached to seeds.  Prairie Smoke grows in full sun and part sun in dry prairies and open woodlands.  Their flowers are pollinated by bumble bees.  Medicinal tea was made from the roots by Native Americans and early settlers.  Another common name is three-flowered avens and old man's whiskers.
Invasive Plant of the Month
Red Clover
© 2007 K. Chayka
Trifolium pratense

Moisture: Dry
Exposure:  Full Sun 
Blooms: June- September
Color: Pinkish-Purple 
Height: 0.5-1.5 feet

Red clover was introduced as a forage crop for cattle. It is from Europe, Asia, and Africa. It has small, round balls of flowers that are pinkish/purple and white. Their leaves are oriented into sets of three leaflets that are oval shaped with a light white V-shaped pattern. Red Clover stems branch out from the base of the plant. It is a very common clover that can out compete natives in our prairies. Management strategies include mowing, hand pulling, and timed, select herbicide treatments.

Native plant alternatives include Prairie Smoke and Purple Prairie Clover!
Pollinator of the Month
Photo by Heather Holm
Small Carpenter Bees
Certina spp.

Range : Throughout North America  
Identification  These are small, solitary bees that nest in the cavities of plant stems. They are nearly hairless, blue/black, metallic looking, with a small white marking on their face. 
Pollination: Small Carpenter bees visit many different species of native plants throughout the growing season for pollen and nectar. This includes Wild Geranium, Spiderwort, Blue-Eyed Grass, Butterfly Milkweed, Harebell, Sneezeweed, Blue Lobelia, and others. They transfer the pollen on tiny hairs on their legs.

Heather Holm's new book Bees: an Identification and Native Plant Forage Guide is now available! 
March 2017 Issue
Our Company
Retail Nursery News
Our retail nursery is currently closed. But will reopen this spring! Check out our 2017 retail hours below:

10 am - 4 pm only on the following days:

May 18 Closed
May 25 Closed
June 1 June 3
June 8 June 10
June 15 June 17
June 22 June 24
June 29 Closed
July 20 July 22
Aug. 17
Aug. 19

Our retail nursery address is:
1480 County Rd. 90  Independence MN 55359

Have any questions? Contact our greenhouse manager Jill at

Click and visit our website for current
Minnnesota Native Plant Brand ensures that plant species are native to Minnesota. 
Upcoming Events

Shorewood 7th Annual Spring Garden Fair on Saturday March 11th 8:30am-3pm at the Southshore Center 5735 Country Club Road Shorewood MN, 55331

Plymouth Home Expo 6pm-9pm Friday April 7th 9am-1pm Saturday April 8th  Plymouth Creek Center Fieldhouse, 14800 34th Ave. N., Plymouth
5 Plants For...
Spring Color!
The days are getting warmer and longer and that only means one thing, SPRING! Soon things will be shooting out of the ground and turning green again. Spring bees will also be looking for food. Plant these flowers to get April blooms and provide essential food for wildlife.

1. Jacob's Ladder
(Polemonium reptans)

2. Wild Geranium 
(Geranium maculatum)

3. Marsh Marigold
(Caltha palustris)

4. Golden Alexander
( Zizia aurea)

5. Prairie Smoke
(Geum triflorum)

 Want to learn more about these native plants? Click Here to visit our website!