Black Knot Fungus Looks Like a Burned Marshmallow on a Twig

While walking through a woodland, have you ever noticed the occasional black stuff on twigs that resembles burned marshmallows? A fellow master naturalist suggested the black stuff looks like scat on a stick.  The black stuff is neither of these but rather a fungus called “black knot”. Black knot fungus grows on species in the Prunus genus which would include our native black cherry, choke-cherry, pin cherry, American wild plum and a few others.

Black knot fungus. Copyright 2011 Landscape Restoration Inc.

By properly pruning away and removing the fungal growth, plants typically recover from black knot fungus if treatment occurs early enough. If you decide to prune black knot fungus from your cherry or American wild plums trees and shrubs, here are some tips that I found to be helpful:
1. Prune in dry weather, preferably during winter.
2. Don’t leave the black growths in the woodland. Place them directly into a bag after pruning and then burn or keep bagged and place in your garbage.
3. Prune 3 – 6″ below the fungal growth or until the pith of the branch is clear without dark spots. Prune the infected branch to a point where the fungus is no longer visible to avoid return of the black knot fungus.
4. When you are through pruning, clean pruning blades with rubbing alcohol to avoid spreading spores during future use.
5. If you are still with me, check out this video of me pruning black knot in my woodland.

The good news is that there is a bit of a silver lining to finding black knot fungus. Buckthorn resembles plants in the Prunus genus but buckthorn is not susceptible to black knot. Therefore, if you do find black knot on woodland shrubs or small trees you have certainly found a native plant that is valuable to native wildlife.

Get outside today and notice something interesting about nature. Nurture a native tree and kill buckthorn!

Cheryl Jirik
Landscape Restoration, Inc.

Posted in Black knot fungus removal, Buckthorn Control, Buckthorn Identification, Buckthorn Replacement Plants, Habitat Restoration, How to Identify Buckthorn in Your Woodland, Native Plant Species, native species, Native Woodland Plants, Non native invasive plants, Winter Identification of Buckthorn | Tagged , , , , , , , , , | Leave a comment

Buckthorn Removal in Minnesota

It seems to me that many folks removing buckthorn are not aware of how to effectively and economically apply herbicide. Often with the cut-stump method, the entire stump is painted or sprayed with herbicide when only buckthorn’s cambium layer is affected by herbicide application. The cambium is a microscopic tree layer that sits just inside the inner bark. In the photo below, I illustrated the herbicide treatment area with blue paint. Notice the black arrow pointing to a barely visible line denoting the location of the cambium layer.

Copyright 2012 Landscape Restoration, Inc. Cut-stump herbicide treatment area.

Only the outer circumference of freshly cut stumps, where the cambium layer is located, needs to be treated with herbicide.  Some older herbicide labels recommend drilling holes in the middle of the trunk and pouring in herbicide – egad! Since this area is the dead heartwood responsible only for holding the tree upright, I wonder why this application would be suggested. Hmmm . . . perhaps a financial motivation on the part of the manufacturer? Back to the point that only the cambium is responsible for drawing down and storing energy into buckthorn’s root structure. When herbicide is applied to the cambium layer it hitches a ride downward to kill the buckthorn root structure and avoid regrowth. You can save time and money by limiting herbicide application to the cambium, not the whole stump.

Another factor affecting my successful buckthorn removal is the herbicide’s active ingredient. I prefer to use a herbicide containing 18-20% glyphosate as the active ingredient. (The reasons I prefer to cut-stump treat buckthorn with glyphosate will be saved for a future blog segment. Something to look forward to!) Glyphosate is sold under various brand names but the most common is Roundup. Whether purchasing Roundup or a generic brand, I check the manufacturer’s product label in the bottom right corner of the herbicide container for the product’s Active Ingredients.


Copyright 2012 Landscape Restoration, Inc. Herbicide label – active ingredient listing

For cut-stump treatment of buckthorn, I want the active ingredient to be glyphosate at 18% to 20% as shown in the photo at right. I use this concentration as is to fill my Buckthorn Blaster applicator and apply herbicide. The 4-ounce Buckthorn Blaster easily keeps me going for 4 to 6 hours of woodland fun. Buckthorn Blasters can be purchased online at

Now that you know my tips to save time and money at buckthorn removal, don’t let your door knob hit you in the rear as you rush outside to eradicate buckthorn. Happy buckthorn busting:)

NOTE: I store my herbicide in an area protected from freezing during winter so the effectiveness will not be diminished.

Cheryl Jirik
Landscape Restoration, Inc.


Posted in Buckthorn Control, Buckthorn Control Methods, Cut-stump buckthorn removal method, Habitat Restoration, How to Identify Buckthorn in Your Woodland, Invasive Species, Non native invasive plants, Winter Identification of Buckthorn | Tagged , , , , , , , , , , , , , , , , , , , | 2 Comments

Buckthorn Replacement & Ground Cover

The fall colors of many native woodland plants are beginning to peak and native woodbine and Virginia creeper are no exception. It may be fun to compare their fall color in the photos below to photos taken earlier this season in our 6-27-12 blog article, “What’s that Plant in My Woodland“.

Copyright 2012 Landscape Restoration, Inc. Woodbine climbing along a small tree.

2012 Copyright Landscape Restoration, Inc. “Virginia creeper as a ground cover in fall”

Virginia creeper and woodbine are almost in full fall color in these photos. Virginia creeper and woodbine provide a great native vining ground cover and also climb fences, trees and other nearby structures. Unlike wild grape, these vines are gentle climbers and will rarely choke out shrubs and trees.

Woodbine and Virginia creeper produce native edible berries for our native birds that are a great food alternative to buckthorn berries. Consider doing a frill cut to your larger buckthorn and then encourage these native vines to use the dead buckthorn as a natural trellis. This is a great option to keep your privacy and stop buckthorn berry production.

     Copyright 2012 Landscape Restoration, Inc.  Woodbine decorating my chicken pen.Copyright 2012 Landscape Restoration,  Inc.  Allow native vines to use a dead tree as a natural trellis.



If you are feeling a little creative, the vines of the less desirable native river grape plant can be pruned from the woods and wound around your porch railing as a decorative accent or wound into a wreath base to decorate for fall and hang on your front door. Go outside and have fun with the natives!

Cheryl Jirik
Landscape Restoration, Inc.

Posted in Buckthorn Control, Buckthorn Control Methods, Buckthorn Replacement Plants, Habitat Restoration, Native Plant Species, native species, Native vines to replace buckthorn removal site, Native woodland ground covers, Native Woodland Plants, Photos of blooming native MN plants, Vining species | Tagged , , , , , , , , | Leave a comment

How to Identify Buckthorn in Your Woodland

The cooler temperatures of fall make it a great season to work on removing buckthorn. Many of our native trees and shrubs change leaf color and begin dropping their leaves in fall. This provides the buckthorn novice with better odds to correctly identify buckthorn compared to the valuable native trees and shrubs we want to keep and protect.

If you would like to improve your ability to confidently identify buckthorn, use these key common buckthorn leaf characteristics:

Copyright 2012 Landscape Restoration, Inc. “Common Bucktorn Leaf”

1.  Notice the indented mid-vein of the buckthorn leaf which runs from the leaf bottom to the leaf tip. Common buckthorn (Rhamnus cathartica) will have 3 or 4 upward curving veins on each side of the mid-vein. This is the most important feature to find but must be combined with the following additional leaf characteristics.
2. The leaf shape is typically a oval – wider across the leaf center.
3. The leaf margin or edges of the leaf are slightly serrated or toothed.
4. The leaf remains green in the fall.

Common buckthorn berries are only found on mature female buckthorn plants and will look like this in the fall:

Copyright 2012 Landscape Restoration, Inc. “Common Buckthorn Berry”

1. Berries of common buckthorn become purple to purple-black in late summer to early fall. Each berry contain 3 to 4 seeds which remain viable in the soil for at least 5 years after dropping from the buckthorn plant or birds who eat the berries. Some buckthorn trees produce thousand of berries per season. You can do the math and understand why buckthorn becomes invasive in a short time span and remains a problem even after the mature trees are removed.
2. The stem of each common buckthorn berry attaches directly to the twig. Berries of native species like choke-cherry, black cherry, nannyberry, etc. form a group and this group is then attached to the twig by one stem.

Now that you are on your way to becoming an expert at identifying common buckthorn in the fall, refer to my blog “Buckthorn – is it a Problem on Your Property” dated 2/15/12 too learn about winter bud identification of buckthorn when the leaves are gone.Go outside today and start getting rid of non-native & invasive common buckthorn. Remember to check out our Buckthorn Blaster herbicide applicator product for cut-stump treatment of buckthorn found under the PRODUCTS tab at

Cheryl Jirik
Landscape Restoration, Inc.


Posted in Buckthorn Berry Characteristics, Buckthorn Control, Buckthorn Identification, Buckthorn Leaf Characteristics, Common Buckthorn Leaf Characteristics, Habitat Restoration, How to Identify Buckthorn in Your Woodland, Invasive Species, Native Plant Species, native species, Non native invasive plants, Winter Identification of Buckthorn | Tagged , , , , , , , , , , , , , , , , , , , | Leave a comment

Buckthorn Education

“Buckthorn Basics & Beyond”City of Eden Prairie Community Ed Class
Presented by Cheryl Jirik of Landscape Restoration, Inc.
Saturday, October 6, 10:00 to 11:30 AM

Learn how to rid your property of buckthorn and restore the native habitat that will benefit hundreds of wildlife species. Know how to positively identify buckthorn in comparison to desirable native species commonly confused with buckthorn. Various buckthorn control methods and pros/cons of each will be presented. If time and weather permit we will head outside to practice buckthorn ID skills and practice the cut-stump buckthorn treatment method. The Buckthorn BlasterTM herbicide applicator for cut-stump treatment of buckthorn will be available for purchase at a special price of $5. Go to to view the Buckthorn Blaster products.


Registration: Refer to class code 33793 when registering Cost: $7
Register by phone: contact Stan Tekiela, City of Eden Prairie Naturalist at 952-949-8479
Register online: Via eConnect at
: Eden Prairie Outdoor Center, 13765 Staring Lake Parkway, Eden Prairie, MN

Please join me for this opportunity to teach you best practices to control and get rid of buckthorn, purple loosestrife control, Canada thistle control garlic mustard control and other non-native invasive plants. Control of invasive species is the first step to the restoration and protection of our native plant and animal habitat. I will be on hand after the seminar to answer questions. Our Buckthorn Blaster and related products will be on  sale for special seminar pricing.

If you have questions related to buckthorn control, please email me at .


Cheryl Jirik
Landscape Restoration, Inc

Posted in Buckthorn Control Methods, Buckthorn Identification, Canada Thistle control, Habitat Restoration | Tagged , , , , , , , , , , , , | Leave a comment

NON-NATIVE PURPLE LOOSESTRIFE CONTROL – Control Instructions with Photos

Blossoming spikes of purple loosestrife. Copyright 2012 Landscape Restoration, Inc.

The purple/pink blossoming spikes of Purple Loosestrife (Lythrum salicaria) are so beautiful this time of year that I wish this plant could be native to our area. Those responsible for its intentional introduction felt the same way. In Europe and Asia, purple loosestrife’s native homeland, specialized insects and disease control its spread. But purple loosestrife is not a native plant to North America and thus there are no native predators to keep this plant from invading and damaging our wetland areas. Biological control of purple loosestrife has been used with great success in some locations as detailed in this article from the Minnesota DNR and Dept. of Ag:


Purple loosetrife taking over a wetland. Copyright 2012 Landscape Restoration, Inc.

Biological control can be a wonderful tool in the tool box to control non-native invasive plant species but it will always have some level of disadvantage. It takes time for those little leaf-eating beetles to get established in your growing patch of purple loosestrife. The word “control” infers control, not eradication. It’s been indicated to me that I have a controlling personality. I think “eradicating personality” would be more accurate. If resources permit, I want purple loosestrife and other non-native invasive plants eradicated from my property. This may be unrealistic in some cases but I can’t hit the moon if I’m shooting for the top of the old oak tree. Please read on if you have an eradicating personality. Here is my step-by-step guide to getting rid of non-native purple loosestrife.

Step 1. Correct plant ID

Correctly ID purple loosestrife by its blossome and these opposite leaves. Copyright 2012 Landscape Restoration, Inc.


It’s important to correctly ID any plant before you begin your “eradication” effort. Note the appearance of the plant and blossom in the photos above and the leaves opposite each other on either side of the stem.

Step 2. Find the stem base

I flatten down the grasses immediately surrounding the stem for better access to the base of the purple loosestrife stem. Cutting the stem close to ground level will allow the follow on herbicide treatment to be most effective.

Step 2. Flatten vegetation around the stem base for best access to cut and treat. Copyright 2012 Landscape Restoration, Inc.


Step 3. Cut the purple loosestrife stem


Apply 18-20% glyphosate to freshly cut stem. Copyright 2012 Landscape Restoration, Inc.

Use a sharp hand pruner to cut the fibrous purple loosestrife stem just above ground level.

Have your herbide and applicator ready for the next step.


Step 4. Apply herbicide to the freshly cut stump

Buckthorn Blaster is used to apply herbicide to freshly cut stem. Copyright 2012 Landscape Restoration, Inc.

This is my favorite part – permanently doing away with this non-native invase plant.  I use the Buckthorn Blaster herbicide applicator to apply herbicide to freshly cut purple loosestrife stems. The herbicide is the same as for cut stump treatment of buckthorn – 18-20% glyphosate* (aka RoundUp Concentrate Plus).  I always include blue indicator dye when filling my Buckthorn Blaster with herbicide. It makes it so much easier for me to tell which stumps have been treated.

* If you are near water, use an aquatic from of glyphosate such as the brand name Rodeo.

Write a reply to this blog if you have questions related to cut-stem treatment of purple loosestrife, or would like to share your ideas for controlling invasive species.

Until next time, get outside and go native.

Posted in Invasive Species, Native Plant Species, Non native invasive plants, Purple loosestrife control | Tagged , , , , , , , , , , , | Leave a comment

Look What I Found – Monarch Caterpillar

While walking through our prairie this weekend to take plant photos I stopped to admire the blossom on a swamp milkweed plant (refer back to previous blog article for photos and value of native milkweed plants) and found this adorable little guy (gal?). I am not an expert on Lepidoptera (nor did I sleep at a Holiday Inn Express last night!) but it seems a little late in the season for a Monarch (Danaus plexippus)to be at this stage of growth. Any Monarch specialists out there who would be willing to share information on the typical growth stages of this beautiful butterfly?


Monarch caterpillar in mid August (Copyright 2012 Landscape Restoration, Inc.

Like this adorable caterpillar and its fascinating story, take time to stop and admire the treasures nature has to share with you today.

Cheryl Jirik
Landscape Restoration, Inc.


Posted in Monarch Butterly | Tagged , , , , , , , , , | Leave a comment

Native Flowering Rain Garden Plants – What’s Blooming in Mid-August

In spring of 2011, I bought an assortment of native Minnesota rain garden plants from the Rice County SWCD (Soil & Water Conservation District). For several years, I had wanted to convert a very small “wettish” area of my lawn into a sample rain garden. Once I took delivery of my 40-plus assortment of healthy new plants it seemed I was committed to this project or my money and plants would be wasted. I removed the sod layer and started planting a few of those new plants.

The area I chose for my little rain garden was frequently saturated after a rain – a good thing for a rain garden. It was along my neighbor’s split rail fence so I would no longer have to tediously mow under the lowest fence rail – another good thing. My neighbors had plantings on their side of the fence which was yet one more good thing and here is why. Author Douglas Tallamy, in his book titled Bringing Nature Home, encourages urban/suburban homeowners to plant along each other’s property boundaries because it provides a larger segment of habitat for native insects, birds, etc. versus each neighbor having an unattached garden in the middle of their property.

A little more than a year after planting, here is what’s blooming in my little rain garden:

Cardinal-flower (Lobelia cardinalis) Copyright 2012 Landscape Restoration, Inc.Boneset (Eupatorium spp.) Copyright 2012 Landscape Restoration, Inc. Sneezeweed (Helenium autumnale) Copyright 2012 Landscape Restoration, Inc.


Blue lobelia (Lobelia siphilitica) Copyright 2012 Landscape Restoration, Inc.

I’ve heard people say they don’t like native plants because they are ugly but I believe otherwise. So do all the butterflies, bees, birds and other pollinators who are enjoying my native MN plants.

Get outside and go native!

Swamp milkweed (Asclepias incarnata) Copyright 2012 Landscape Restoration, Inc.)

Cheryl Jirik

Posted in Native Plant Species, Photos of blooming native MN plants, Rain Garden Plants | Tagged , , , , , , , , , , , , , , , , , , | Leave a comment