Isn’t this a pretty plant?

Smells good, too.

It produces edible berries that birds love.

Sometimes it is difficult to make an invasive species out to be the “bad guy” that it is.

It’s certainly easier to dislike…Poison Ivy, say…than this lovely shrub!

Autumn Olive (Elaeagnus Umbellata), also known as Oleander or Japanese Silverberry has plenty of good things going for it, sure.


  • The rapid growth and ability to provide a canopy of shade quickly displaces natural plants.
  • The ability to set nitrogen in the soil makes the ground too rich for many native species.
  • The berries are widely dispersed by birds, so spread is uncontrolled.
  • It has been noted that the variety of birds is reduced, in areas where Autumn Olive berries are the main food source.


Pretty as it is, this is not a plant we want taking over our fields and open areas.

Let’s continue to be watchful!







Scots Pine is an evergreen tree native to Europe and Asia. “Scotch pine has the largest geographic range of any pine, from Great Britain, Ireland, and Portugal east to eastern Siberia. It grows above the Arctic Circle in Scandinavia and south to the Mediterranean”.  Mature stands of Scots Pine found in Europe are often quite beautiful, as the trees have a symmetrical shape (think Christmas tree!) and distinctive red-orange bark.

They rarely do so well here, though. Easily turned by wind and weather, unless grown in the controlled environment of a tree farm, Scots Pine is usually a crooked, misshaped tree.


An invasive, non-native species like Scotch pine is a problem. Not only does it spread into open areas, but it displaces other native species. Scots pine is susceptible to disease and insect problems that can then infect native pines.

One of only three pine species on Beaver Island, Scots pine has very short, twisted needles (no more than two inches long) that occur two in a bundle. This makes it easily distinguishable from our native pine trees:the white pine has five needles in a bundle; the red pine, also native, has needles – two in a bundle – that are four to five inches long.

Once again, awareness is the first step in maintaining our precious landscape.



Marsh Thistle.

Cirsium Palustre.

European swamp thistle.

Marsh plume thistle.

Many names for yet another invasive plant species.

This one has been described, “like purple loosestrife, with spines.”

Marsh Thistle is a member of the Aster family with origins in Europe.

It is an erect herbaceous biennial that can grow 3 to 5 feet in height. Once again, I go to the informative brochure, Top Ten Invasive Species, put out by the Beaver Island Association  for their excellent description:

[Marsh Thistle]has a rosette (circle) of leaves at the base that are long, spiny, and deeply lobed. The stem is thick, often reddish, and covered with hairy spines and equally spiny, hairy leaves. The pinkish-purple flowers appear at the top of the stem in a tight cluster, usually in June or July. On Beaver Island this plant is more likely to be found in moist areas than in dry sand.

The brochure goes on to warn that there are some similarities with the native Pitcher’s (beach) thistle, which is a federally threatened (and protected!) species. If in doubt, consult an expert.

The differences between a native plant and an introduced, non-native plant are vast, and have mainly to do with things that keep a plant in check. From things that slow a plant’s growth at a microbial level, to animals that may feed on it, to natural competition for light and nutrients, native species have checks in place. Invasive species do not.

When I spoke at the school, I compared an invasive plant’s advantage to the powers of Superman. If he had chosen to use his powers for evil, rather than for good, we wouldn’t have had a chance against X-ray vision, the ability to fly, super-strength, super-hearing and super-speed.

When invasive plants move in – usually the initial invasion is caused by the activities of man – there is nothing in nature to stop their progress. If left alone, they will forever change the landscape. We have to take control of the problem.

Marsh thistle forms a rosette the first year, and over-winters at ground level.


The next year, it sends up a stalk, flowers, and produces thousands of seeds…which are then dispersed by the wind.


Once introduced, “this plant can aggressively colonize natural areas, decrease biodiversity and compromise the ecological integrity of an area.” (USDA Forest Service)

Let’s not let that happen here!



Continuing the “countdown” of top ten invasive plants here on Beaver Island, let me introduce Spotted Knapweed.

This herbaceous (non-woody) perennial has a unique island story. I made several attempts to have my facts verified and clarified last week, which resulted in only delays. I am betting that – if I get the story wrong – I’ll quickly be given the corrections, so I’m going to tell it as I’ve heard it. Beaver Island is big on nicknames. Over the years we’ve heard names from “Tight” Gallagher to “Killer” Burke to “Red Pup” and “Hannah”.

This invasive plant has a Beaver Island nickname, too. Here, it is often referred to as “Denemy Thistle”. It was unintentionally brought to the island in a load of hay that William “Denemy” Boyle (a relative, by marriage, of “Harlem” Gallagher) shipped over. It came here when agriculture was still an important  industry on Beaver Island, and was noticed right away as an aggressive and unwelcome weed. My grandfather, George Ricksgers, worked very hard to keep it out of his own fields and pastures, and was successful for a while.

Like all invasive plants, the Spotted Knapweed has advantages over native growth. Along with aggressive growth habit, prolific seed production and a long tap root, Spotted Knapweed is phytotoxic, meaning it is poisonous to other plants. That’s quite an advantage, in taking over an area! It thrives in what are called “artificial corridors”: gravel pits, roadsides, field margins, overgrazed pasture land and beaches. It can quickly take over an area, eliminating pasture, native growth and wildlife habitat. On our beaches, it is a big threat to the piping plover.

When pulling this weed, keep in mind that it looks similar, in some stages of it’s growth, to the endangered and federally protected Pitcher’s Thistle, which is an important part of our natural flora. When in doubt, do a bit more research or ask an expert. The other thing to be aware of is that Spotted Knapweed releases an irritant chemical, so gloves should be worn when in contact with it.

If you’d like more information about this, or any of our top 10 invasive species, the brochure put together by the Beaver Island Association is an excellent resource. Copies are available – free – in the lobby of the Community Center.

If you’d like to be involved in group  projects to help control or eradicate invasive plants, please let me know!


Spotted Knapweed in its first year, rosette stage…


…and here, quickly taking over a construction site.

Let’s continue gaining awareness and working together to protect our beautiful island!



Some of these invasive plants can certainly be deceptive.

Unlike Phragmites, whose sharp, grassy stalks form an impenetrable wall, many herbaceous perennials are actually quite attractive. They seem quite soft and fluffy; often producing striking flowers.

Purple Loosestrife is another one.

First introduced to this country in the 1830’s Purple Loosestrife came here as a contaminant of ship’s ballast. It was also brought here as a medicinal herb, for treatment of diarrhea, dysentery, bleeding, wounds, ulcers and sores. It was welcomed in gardens for its beautiful flowers; beekeepers appreciated the nectar it provided for their hives (though it did not result in a flavorful honey).


Let us not be deceived.


Like all invasive species, this plant does not “play well with others.” It does not co-exist with our native plants. It wants to take over.


Purple Loosestrife is an herbaceous,wetland perennial that can thrive in a wide range of habitats. By the 1850’s it had taken over much of the eastern seaboard. It spread easily as we built and used more inland canals and waterways. Seeds are easily dispersed by water,and by mud adhering to aquatic wildlife, livestock and people. By 1996, Purple Loosestrife had invaded every single one of the contiguous states, except Florida, and every Canadian province!


Established plants grow six to seven feet tall and up to four feet wide. Each plant is made up of 30 to 50 stems, each stem topped with a large, seed-producing flower head. One mature plant can produce more than two million seeds annually! Plants quickly dominate the herbaceous canopy, causing a sharp decline in biological diversity. Infestations can result in a dramatic disruption of water flow. By crowding out native species, they effectively eliminate food sources for many birds and marsh animals.

In addition, note that there is no effective method to completely control this plant, except where it occurs in small, localized stands and can be intensely managed.


The brochure on Beaver Island’s Top 10 Invasive Plants, put out by the Beaver Island Association, offers this good description:

Purple Loosestrife…is most often found in damp habitats. It has a square stem, like a mint, and the pairs of leaves that occur on the stems grow directly opposite each other. The leaves are lance-shaped and the stem and leaves are covered with fine hairs. It flowers from June until September and produces showy spikes of bright pink-purple flowers, sometimes with over 30 stems from a single plant.

The brochure goes on to say that purple loosestrife has been found in scattered clumps around the island, including along the Lake Michigan shoreline.

Beaver Island is still in a position to be able to manage this plant. That alone sets us apart from most shoreline communities in North America! Let’s take advantage of it, with continued vigilance to take care of our wetlands.






Wild Parsnip, like many of our invasive plants, looks harmless enough.

It is an herbaceous (not woody) plant that grows about four feet tall in the full sun of fields and road-sides.

Wild Parsnip is a member of the carrot family, and has a long, thick and edible taproot.

The thick, ribbed stems look a bit like celery.

The compound leaves (many leaflets on a stalk) give it an airy, ferny aspect.

Yellow flowers, produced in July and August, grow in an umbel (think umbrella-shaped),and are similar in appearance to Dill, or Queen Anne’s Lace.

Quite pretty,actually.

Wild Parsnip is also a little bit famous.

It is listed, in some states, as a Prohibited Noxious Weed.

It was featured, last year, on a CBS News broadcast titled, Poisonous Plants Like Wild Parsnip Could Spoil Your Summer.

Not only does wild parsnip have all of the usual oh-so-annoying features of an invasive species (no natural enemies, crowds out native plants, makes areas uninhabitable to native plants and animals…we are starting to see a pattern here, aren’t we?!), but it is also classified as poisonous!

If the sap from cut stems or leaves of this plant gets on the skin, and is then exposed to sunlight, it can cause phytophotodermatitis. That’s a long name which basically describes painful reddening, burning and blistering of the skin. The CBS News report told of a man who was afflicted after mowing through a patch of wild parsnip growing near his home. According to the victim, the pain was tremendous, the blisters lasted for weeks, and the scars much longer. I’ve opted to not put photos of badly reddened, swollen and blistered extremities on this page, but be warned: this is nasty stuff!

Removal of plants by pulling is quite an effective method of getting rid of wild parsnip…but be careful!  Gloves, long pants and long sleeves should be worn when dealing with this plant.

Watch for wild parsnip in fields, road-sides, unmowed pastures, edges of woods and open areas, especially where the natural growth has been disturbed.

Awareness is the first step. With vigilance, working together, we can save and protect our island.





Compared to some of the other invasive species here on Beaver Island, garlic mustard looks pretty benign.

It’s an edible herb, for heaven’s sake!

Well, if any of you have ever seen how quickly a mint plant can spread to take over the herb garden – or the lawn, for that matter – you know that some herbs can be terribly aggressive. Garlic mustard is one of them.

Add to that the fact that it grows in moist shade – like our woodland areas – and the damage it can do becomes evident.

“Garlic mustard poses a severe threat to native plants and animals in forest communities,” according to the Plant Conservation Alliance:

Many native widlflowers that complete their life cycles in the springtime (e.g., spring beauty, wild ginger, bloodroot, Dutchman’s breeches, hepatica, toothworts, and trilliums) occur in the same habitat as garlic mustard. Once introduced to an area, garlic mustard outcompetes native plants by aggressively monopolizing light, moisture, nutrients, soil and space. Wildlife species that depend on these early plants for their foliage, pollen, nectar, fruits, seeds and roots, are deprived of these essential food sources when garlic mustard replaces them. Humans are also deprived of the vibrant display of beautiful spring wildflowers.

In addition, chemicals in garlic mustard appear to be toxic to the eggs of certain butterflies, evident in their failure to hatch when laid on garlic mustard plants.

AND, as appears to be the case with all invasive species, garlic mustard is terribly prolific. Each plant can produce thousands of seeds, which remain viable for several years, scatter and germinate. When pulled, it is important to get the entire root, as new plants can sprout from root fragments.

Fortunately, pulling is still – in the case of this particular invasive plant – a good method of control. Removing plants before they go to seed, or before the seed has scattered, will help to keep garlic mustard from taking over our woodland areas.

Let’s get to know the plant, so we can keep it away.

  • Garlic mustard is a cool season biennial herb.
  • Its leaves are triangular to heart-shaped, with scalloped edges and prominent veins.
  • Leaves give off the odor of garlic when crushed.
  • Plants produce clusters of small white flowers, each with four petals in the shape of a cross.
  • Garlic mustard plants stand 12 to 36 inches tall.
  • On Beaver Island, garlic mustard will be the only plant of its height flowering in the woods in May.

With concern and vigilance, we can protect our beautiful island!