Tag Archive | Invasive

Fire in the Fields

Sumac lighting up a hill in Wisconsin's autumn

Sumac lighting up a hill in Wisconsin’s autumn

It happens every autumn. Huge sweeps of straggly, undistinguished shrubs that grew unnoticed in unkempt fields are suddenly, gloriously, ornamental. The long almost palmlike fronds of leaves shine bright red with hints of yellow and orange. The branches spread like candelabra holding up huge crimson fruit clusters that keep glowing long after leafdrop, when all the world is gray. No wonder gardeners think about bringing sumac in from the wild.

Staghorn sumac in the summer before changing color

Staghorn sumac in the summer before changing color

Sumac grows everywhere, all the way from zone 2 to zone 9. It grows in dry soil, poor soil, moist soil, near-bog, bright sun, and part shade. It spreads by seed and by underground runners that can travel 20 feet or more in search of a good spot to make a new clump of sumac. But if there is also a lawn anywhere nearby, there will be adequate local control as long as you keep mowing.

Smooth sumac (Rhus glabra) is the most common roadside attraction. It’s fuller and more readily clump-forming than staghorn sumac (R. typhina), named for the velvety down that covers every branch. Smooth sumac tops out at about 8 to 10 feet, staghorn at 12 to 16 feet.

Fragrant sumac makes a beautiful garden addition

Fragrant sumac makes a beautiful garden addition

Fragrant sumac (R. aromatica) is shorter, at 3 to 4 feet, and bushier, more like a garden plant. If you decide to bring sumac into your garden or prairie, no matter which type you choose you will need both male and female plants if you want fruits. Sumacs are available through nurseries that specialize in native plants, and some large garden centers will order them for you if you ask.

Note: it’s always a good idea to check whether a plant is considered an invasive species in your state before transplanting from an area where the plant is growing wild. In Wisconsin, the Department of Natural Resources provides a free guide to invasive species here:  DNR INVASIVE SPECIES GUIDE


Expert’s Tip: New Invasive Species Jumping Worms

Lisa Johnson, Dane Co. UW-Extension Horticulture Educator



These invasive worms jump when handled.

As you are doing yard clean-up this fall, there is yet another new invasive pest to look for, identified in Dane County in October of 2013. Jumping worms (Amynthas spp.) are of Southeast Asian origin and they can be very damaging to soil structure in gardens as well as forest environments. No earthworms are native to Wisconsin—they were all killed off during the Ice Age. We do have 20 European species in the state, however. Earthworms all have negative effects on the forest duff or litter layer, which acts as a protective cover and helps forest floors to retain moisture, insulate tree roots, provide nutrients, prevent erosion, etc. When that litter is eaten by earthworms, the protective cover is removed, exposing the soil and causing erosion, compaction and increased runoff. This disturbance favors the spread of invasive plants such as garlic mustard and buckthorn. Researchers have also documented the negative effects of earthworms on forest regeneration and ground nesting bird populations.

The jumping worm is especially destructive since it lives right in the duff layer rather than lower in the soil profile. Jumping worms tend to outcompete European earthworms to become the only species in forest environments. They consume the layer of leaves and other organic matter on top of the soil faster than other earthworm species. They have been found in Dane, Sheboygan, Jefferson, Waukesha, Milwaukee and Racine counties, and signs of the worms (though no adults) have been noted in 8 other counties. Jumping worms have also been found in some states in the Eastern U.S. We don’t know how long they have been here in Wisconsin, but introduction through contaminated soils or plants is suspected. Since they can spread very quickly, it is important to slow the spread. Best management practices are being developed by the DNR and municipalities. Don’t share plant divisions from your garden or soil if you know you have jumping worms.

Jumping worms are parthenogenetic, producing eggs without the need for a mate, so just one worm can start a new population. Their eggs survive as microscopic cocoons over winter, with all the adults dying in fall. You won’t see the young worms until late June each year, but you will see the ‘soil signature’ from their feeding during the previous season. Jumping worms feed on soil organic matter, leaf litter and mulch and create very grainy-looking and hard little pellets when they excrete. The excretions resemble coffee grounds, and have poor structure for plants to grow in. Also, the worms’ feeding removes the organic matter that plants, fungi and bacteria need for nutrients. Adult jumping worms are 3 to 5 inches long but can grow to up to 7 inches in length. Jumping worms resemble regular earthworms but there are some important differences. Unlike European earthworms, they don’t produce slime and are more gray or brown in color than pink. Their clitellum, the band of lighter-colored tissue near the head, is smooth, not raised like other earthworms and whitish, not pink. It also goes all the way around the body, not just partway, like the European worms. The body is more rigid as well. Jumping worms get their name from their behavior—when handled, they thrash violently, may jump into the air or even shed their tails. They move in a serpentine fashion like snakes, as well.  Check out this video to observe them moving.  After hatching in late June, each worm begins reproducing; their life cycle lasts 60 days, so we can have two generations easily each year. Unfortunately, other than killing any worms you find by placing them in a closed plastic bag in the sun, there are no products labeled to kill them, since soil drenches would also kill beneficial soil organisms. Some products are being tested, but I haven’t heard about any results as of yet.

To report a sighting of jumping worms, email Invasive.Species@wi.gov . For more information and to see photos, visit http://dnr.wi.gov/ and search for the keyword ‘jumping worm’. There is also a great article in Wisconsin Natural Resources that you may want to check out . 

Editor’s note: these worms have also been identified in Outagamie County.

A Natural History of Ferns (book review)

this article originally appeared in the Summer 2006 edition of the Outagamie County Master Gardener Association newsletter

Book Review by Karen DesJarlais

A Natural History of Ferns By Robbin C. Moran

imagesI just finished reading this book and I know what you’re thinking. Too many rainy days, must have had trouble sleeping. But you’re wrong; this book is riveting as plant books go. I think you’ll gain new respect for ferns if you didn’t appreciate the wonders of a spore reproducing plant that dates back 340 million years.

The book’s 33 chapters (any one of which could be a stand alone) is organized under six major headings: Life Cycle, Classification, Fern Fossils, Adaptations, Geography, and Ferns and People. You’ll be glad to know that the glossary is clear and will cause you to be a real page turner if you want to enhance your knowledge of ferns or be botanically correct.

Here is the author’s crystallized version of how enriching fern study can be. “Learning the meanings of names of ferns opens a little window that looks out onto pteridology, the study of ferns. Through it you can glimpse people who developed the science, the voyages that brought back to Europe many previously unknown and marvelous species and the ancient cultures and what they believed about plants.

The book has the best explanation I’ve seen of the advantage of using the Latin binomial for plant reference and ex- plains how the process of naming works. To name a “new” plant with a new Latin name, you need to comply with five requirements prescribed by the International Code of Binomial nomenclature. The code evolved over the years and every six years, an International Botanical Congress revises it.

You don’t need to have a PhD in botany or membership in a scientific society to name a new species. Anyone can do it as long as they present evidence that the plant differs from any previously discovered and as long as they follow the rules. Between 1991 and 1995, about 620 new kinds of ferns were described worldwide, mostly in the tropics.

You’ll enjoy the chapter “At the Movies” as it relates to a movie “A New Leaf” released in 1971. The plot centers on the naming of a new fern.

We shouldn’t be surprised that ferns could be invasive. One such purple loosestrife like species is the salvinia mo- lesta. It’s capable of doubling its population in size in just two days. This weedy one clogged irrigation ditches, blocked drainage canals and jammed water pumps. In some places, it harbored the human blood of parasite schis- tosomiasis causing entire villages in the Asian tropics to be abandoned. The story of finding the natural predator for this species is like a CSI.

In contrast, the most economically beneficial ad smallest fern in the world is the Azolla. In North America, it grows in the Mississippi River floodplain of northeastern Arkansas. In Southeast Asia, especially China and Vietnam, it’s a rich nitrogen fertilizer for rice paddies. Nitrogen is release as it decomposes. Because of Azolla, the rice grain is richer in protein than if fertilized with chemical fertilizer. You’ll enjoy the cultural and economic discussion surrounding this tiny fern.

Pteridomania is the most engaging chapter under the “Ferns and People” section as well.

If you enjoyed botany at any point in your life, you’ll love this book. If you didn’t, you’ll find the author’s conversational styles slyly teaches you a lot. Yes, there are pictures; several pages of colored plates and lots of enlightening drawings, many of them done by the author.

I have a whole new respect for the Osmunda claytoniana (interrupted fern) that I just got from Wild Ones. It has a longer fossil record than any other fern, extending back 200 million years.

I found my hardcover of A Natural History of Ferns at the Menasha Public Library. It’s still raining (the ferns love it) and my eyes are getting a little heavy but I know it’s not the book!

My Garden is ‘for the birds’!

Beautiful Cedar Waxwings love the berries from trees and shrubs

Beautiful Cedar Waxwings love the berries from trees and shrubs

Not sure why that phrase ‘for the birds’ denotes a negative connotation; I absolutely love the birds that come to visit my garden.  For that reason, I have bird feeders and bird baths at various locations throughout my garden and I make sure to plant things that will bring them in. Year before last, I was lucky to be visited during Spring migration by a huge flock of Cedar Waxwings — probably 50-60 of them were sitting in one of the Silver Maple trees in my front lawn and flying back and forth to visit the Mountain Ash tree across the street. The birds would fly back and forth, gathering and eating the berries that had been fermenting all winter. How amazingly funny to watch them getting tipsy as they gorged themselves on the berries (dropping them all over my driveway in the process)! A wonderfully enjoyable day where I got nothing done but watching the birds!

If, like me, you want to bring in the birds, you might want to consider planting some of the following:

  • Winterberry – not only will the birds love it, you’ll get lovely branches to combine with evergreens for winter containers
  • Juniper – remember: juniper berries are a basic ingredient in gin. No wonder the birds love them!
  • Serviceberry – berries are edible for people, too
  • Hawthorn – thornless varieties are available to protect both yourself and children
  • Crabapple – almost an endless array of choices in size, style, and color
  • Mountain Ash – requires a little care, but it’s such a favorite of birds
  • Elderberry – the flowers add a lovely aroma to your garden, while the berries are delicious for both birds and people. Elderberry jam or wine is absolutely delicious.

Better to avoid planting these wildly aggressive invasive plants if you can:

  • Bayberry – I have two of these (one purple / one yellow) in my garden, but recent studies question whether these shrubs are a threat to public health.  20 states have named the Japanese Barberry as an invasive species and a restricted plant in Wisconsin by the DNR. If you have these shrubs, as I do, it’s important to keep them contained. The branches have thorns, making it a perfect hiding place for small birds, and the berries provide sustenance in the winter but, unfortunately, allow the spread of the seeds of this aggressive shrub. The smart thing is to eventually replace them with something more environmentally friendly.
  • Buckthorn
  • European cranberry bush vibernum
  • Mulberry
  • Smooth sumac

Want some additional ideas to help our feathered friends, the environment, and your garden? Visit this article at EcoSystem Gardening to learn more: http://www.ecosystemgardening.com/native-alternatives-to-invasive-plants.html

Posted by Vicki

Plant Goldenrod in Your Garden – Don’t Blame it for Your Allergies!


Tall, showy goldenrod

I was talking with a friend (with a degree in Horticulture) recently and he suggested that I add some goldenrod (Solidago sp.) to my gardens for height and that beautiful yellow color. My immediate reaction was “Won’t that make me sneeze even more each Spring?!”  As it turns out, I’m not the only one to confuse my sneezing each spring with the blooming of this lovely plant. The real culprit (ragweed) bears some resemblance to goldenrod, but is easily identifiable with just a little research.

Purplish stems of the ragwood plant.

Purplish stems of the ragweed plant.

Alicia R. Lamborn, Environmental Horticulture Agent for the Baker County Extension of the University of Florida, has written a paper addressing the difference between these summer blooming plants.  To access that article, click here; then plant some beautiful goldenrod in your garden and ignore the box of tissues!

Posted by Vicki