Exotic invasive plants, and what to do about them

pigdoc

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Have been incredibly busy at work - the bird flu season has started early this year.

I have been doing battle with exotic invasive plants on my 12-acre fully wooded property for years. The battle front is steadily advancing towards complete victory in another year or two.

First, how to define an "exotic, invasive plant"?
Many of the plants common in our environments were imported, either recently, or in the distant past. At some point, I guess, they all become "native", as opposed to exotic. But, the exotics I target do not have redeeming qualities as a food source for native wildlife. And, from my short list below, most will agree that they are truly "invasive" and will take over a landscape, if you let them. In general, the exotics stand out as they are the last to wither in the winter, and the first to green up in the spring. In mild winters, they will remain green all winter. So, they outcompete and crowd out the native plants.

My short list (the ones I'm currently targeting most aggressively):
1. Oriental bittersweet - vines that climb trees, choking them, getting as big as your arm in diameter.
2. Porcelain-berry - another vine, closely resembles grapevine, but with a different bark and hard, blue, pea-sized berries. Another tree-climber.
3. Japanese barberry - a prolific shrub with thorns and small, oblong, red berries. Must be distinguished from native barberry, by the thorn pattern.
4. Multiflora rose - large thorny shrub, very common across the US. Imported for use as a natural fence, but very invasive.
5. Hedge laurel - not highly invasive, imported from Europe.
6. Bush honeysuckle - tree-like large shrub with arcing branches and shreddy bark, pleasant-smelling prolific blossom, red fruit is winter food for birds, but is VERY invasive, as it is spread by birds.
7. Kudzu - Thorny, woody vine, most common in the southeast US. Very invasive, spreads via underground rhizomes.
8. Angelica and related Asian tree-like plants, including tree-of-heaven (Ailanthus), the favorite of Spotted Lanternfly. Have compound leaves like native sumac, and often, thorny stems. Common along roadways, railbeds, and power-line corridors.

In particular, the growth of oriental bittersweet, multiflora rose, kudzu, and Angelica will actually be stimulated by efforts with a saw, mower, or a blade. Burying the shredded growth in a nutrient-dense material (mulch or compost) will make them very happy indeed. And, don't think about trying to pull them out by the roots. The root fragments left behind will quickly sprout and regrow. All of these exotic invasives quickly populate clearings in the woods. My most troublesome areas are the borders of the small lawn around the house, and along the driveway, where light has recently been introduced to the forest floor.

My MO is to use some kind of hand clipper (short-handled, or long-handled) to clip these plants off at ground level. You may need a hand saw for the bittersweet vines and bush honeysuckle. For large tree-of-heaven, I girdle them in the spring with a hatchet. Then, I immediately paint the stump with straight, 41% glyphosate concentrate. I use a small, 2-ounce shoe polish applicator - the kind that you pump to moisten a foam applicator. Two ounces will typically last me a couple of hours when I'm working. Now, before anyone has a cow about the "chemicals", realize that glyphosate is about the safest herbicide there is, from an environmentally conscious standpoint. It is rapidly degraded by soil bacteria and its half-life in soil is about 24 hours. This kind of focused (not broadcast) application is very discrete, so you're not killing nearby native plants. Don't use it near surface waters, as it is quite toxic to aquatic animal life. I'm always wearing thick gloves when I do this work, so I have no worries about skin contact. Typically, I will gather up the clipped off aerial parts of the plants and promptly burn them, so they have no chance of re-rooting.

Yes, this is a lot of work, but a thorough approach will permanently eliminate these nuisance plants. And, preserve the native plants around them, to quickly take over the void. Areas that I have cleared of exotic invasives become carpeted with bracken and ostrich fern the very next spring. Beautiful!

Now, go out and reclaim your property!
-Paul
 
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Biker1mike

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I have a large section of Golden Bamboo which is banned in NY. It was here when I bought the property over 20 years ago so I am grandfathered in and am not required to dig it up. I try to keep it in check by hand cutting new growth and keep a 4 foot path with the blade as a slow down buffer. Not sure if there is a way to get rid of all of short of an excavator. To close to a non-trout stream that does feed a trout stream just down the road to use poison.
 

Russell King

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Good luck on your tasks

I have about five acres that was neglected and is along a river so has been flooded a few times.

Texas is overrun with non native plants also that the flooding helps to move around. I have eradicated the chinaberry trees and the johnson grass and the beggars lice so far. But the seed bank is well stocked with these so it is a challenge to keep them from getting established again every year.

now I am trying to eradicate grasses (King Ranch bluestem) that are not native but close enough that they are difficult to distinguish from native and prolific growers.

the flooding also spreads undesirable natives (spiny cactus and juniper tree) that will show up often even though I am sure that they have never been there before.

it is satisfying and frustrating at the same time
 
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fried1765

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Have been incredibly busy at work - the bird flu season has started early this year.

I have been doing battle with exotic invasive plants on my 12-acre fully wooded property for years. The battle front is steadily advancing towards complete victory in another year or two.

First, how to define an "exotic, invasive plant"?
Many of the plants common in our environments were imported, either recently, or in the distant past. At some point, I guess, they all become "native", as opposed to exotic. But, the exotics I target do not have redeeming qualities as a food source for native wildlife. And, from my short list below, most will agree that they are truly "invasive" and will take over a landscape, if you let them. In general, the exotics stand out as they are the last to wither in the winter, and the first to green up in the spring. In mild winters, they will remain green all winter. So, they outcompete and crowd out the native plants.

My short list (the ones I'm currently targeting most aggressively):
1. Oriental bittersweet - vines that climb trees, choking them, getting as big as your arm in diameter.
2. Porcelain-berry - another vine, closely resembles grapevine, but with a different bark and hard, blue, pea-sized berries. Another tree-climber.
3. Japanese barberry - a prolific shrub with thorns and small, oblong, red berries. Must be distinguished from native barberry, by the thorn pattern.
4. Multiflora rose - large thorny shrub, very common across the US. Imported for use as a natural fence, but very invasive.
5. Hedge laurel - not highly invasive, imported from Europe.
6. Bush honeysuckle - tree-like large shrub with arcing branches and shreddy bark, pleasant-smelling prolific blossom, red fruit is winter food for birds, but is VERY invasive, as it is spread by birds.
7. Kudzu - Thorny, woody vine, most common in the southeast US. Very invasive, spreads via underground rhizomes.
8. Angelica and related Asian tree-like plants, including tree-of-heaven (Ailanthus), the favorite of Spotted Lanternfly. Have compound leaves like native sumac, and often, thorny stems. Common along roadways, railbeds, and power-line corridors.

In particular, the growth of oriental bittersweet, multiflora rose, kudzu, and Angelica will actually be stimulated by efforts with a saw, mower, or a blade. Burying the shredded growth in a nutrient-dense material (mulch or compost) will make them very happy indeed. And, don't think about trying to pull them out by the roots. The root fragments left behind will quickly sprout and regrow. All of these exotic invasives quickly populate clearings in the woods. My most troublesome areas are the borders of the small lawn around the house, and along the driveway, where light has recently been introduced to the forest floor.

My MO is to use some kind of hand clipper (short-handled, or long-handled) to clip these plants off at ground level. You may need a hand saw for the bittersweet vines and bush honeysuckle. For large tree-of-heaven, I girdle them in the spring with a hatchet. Then, I immediately paint the stump with straight, 41% glyphosate concentrate. I use a small, 2-ounce shoe polish applicator - the kind that you pump to moisten a foam applicator. Two ounces will typically last me a couple of hours when I'm working. Now, before anyone has a cow about the "chemicals", realize that glyphosate is about the safest herbicide there is, from an environmentally conscious standpoint. It is rapidly degraded by soil bacteria and its half-life in soil is about 24 hours. This kind of focused (not broadcast) application is very discrete, so you're not killing nearby native plants. Don't use it near surface waters, as it is quite toxic to aquatic animal life. I'm always wearing thick gloves when I do this work, so I have no worries about skin contact. Typically, I will gather up the clipped off aerial parts of the plants and promptly burn them, so they have no chance of re-rooting.

Yes, this is a lot of work, but a thorough approach will permanently eliminate these nuisance plants. And, preserve the native plants around them, to quickly take over the void. Areas that I have cleared of exotic invasives become carpeted with bracken and ostrich fern the very next spring. Beautiful!

Now, go out and reclaim your property!
-Paul
Bittersweet has been invading my 11.7 acre property for years.
At 82 I am just too old to deal with it.
I have surrendered.... to the bittersweet!
 
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ken erickson

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Paul,

Thank you for the write up!
I am also battling invasive species on my oak/savanna restoration project in Central Wi.
My main foes are

Spotted Knapweed
Buckthorn
Black Locust
Scot Pines

Unfortunately as you mentioned some of the species can not be eracticated without the use of herbicides.

A issue that is not discussed a lot when I chat with our DNR and habitat organizations is what our neighbors are doing or not doing to keep invasive species controlled. I my case I have spent many $'s and time to try and control Spotted Knapweed but 2/3rds of my neighbors either do not have the resources, knowledge or interest in controlling theirs. With wind born seeds propagating the invasive species this can become a daunting task.

Last summer I had the good fortune to have some help spot treating Spotted Knapweed with a product called Milestone. The help was from an intern finishing up her college courses at one of the University of Wi campus's that offers many DNR and habitat type courses.

Keep fighting the good fight and thanks again for your write-up.

Ken

DSC03823.JPG
 
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DaveFromMi

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I have an annual battle with multifloura rose, blackberry, bush honeysuckle, autumn olive, Japanese honeysuckle, tree of heaven, poison ivy, and several other thorny bushes that don't belong here. I buy concentrated triclopyr from TSC. It works better that glyphoshate for these tough plants.
After about 15 years, they are under control, but still need to kill new plants every year.
It would help if the neighbors would take care of theirs as well.
 
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PoTreeBoy

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My nemeses:
Sweet gum
Ligustrum
Russian/August Olive (I don't know the difference)
Multiflora Rose (I just have a little, and it's where I can keep an eye on it)
My goal is minimal chemical.
 

Russell King

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One thing about glyphosate that I found helpful in killing the Johnson grass (spreads by prolific seed and rhizomes) was to use weaker solutions so it would have time to get throughout the plant before the leaves were too dead to absorb the herbicide

but it is non selective so somewhat difficult to apply by spray but wipers work better but slower process by hand
 

Trapper Bob

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The NRCS in my area recommended diesel fuel & Remedy mixed 3 to 1 for trees & woody plants. It works pretty good on the Multiflora rose after cutting the rose at the ground & treating the stump. I put a little dye in the mix to prevent missing spots.
 

Flintknapper

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Good luck on your tasks

I have about five acres that was neglected and is along a river so has been flooded a few times.

Texas is overrun with non native plants also that the flooding helps to move around. I have eradicated the chinaberry trees and the johnson grass and the beggars lice so far. But the seed bank is well stocked with these so it is a challenge to keep them from getting established again every year.

now I am trying to eradicate grasses (King Ranch bluestem) that are not native but close enough that they are difficult to distinguish from native and prolific growers.

the flooding also spreads undesirable natives (spiny cactus and juniper tree) that will show up often even though I am sure that they have never been there before.

it is satisfying and frustrating at the same time
Never ending battle in East Texas to keep the Flora beat back.

China Berry Trees, Honey Locust, Privet Hedge, Black Berry, Green Brier, Sweet Gum Saplings.

I am forever burning brush piles and making new ones. Its a challenge for one person to 'clear' new parts of the property while 'maintaining' the rest.

Winter time (only a couple of Months here) is all the time I have to make any headway. Then its back to maintaining what has been cleared/thinned/improved.

 
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GeoHorn

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Here’s a Marine demostration:





EFB2E921-0E42-40B2-A303-A36E83EC5352.png
 
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anomad

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A good chunk of my property was cow pasture until the late 90's or so. Then left to grow over. One south facing section came back in pines and others closed in with hardwoods nicely. But a couple areas are a mess. Bitterweet, privet, multiflora rose, and the worst - japanese stiltgrass.

Sprang for a very expensive selective herbicide for the stiltgrass. Works out to like 2 dollars a gallon, which isn't bad. But paying over 100 dollars for like a pint kind of stings.

I would like to pursue grant money to restore riparian areas on the property. But haven't really pursued it.
 

fried1765

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The NRCS in my area recommended diesel fuel & Remedy mixed 3 to 1 for trees & woody plants. It works pretty good on the Multiflora rose after cutting the rose at the ground & treating the stump. I put a little dye in the mix to prevent missing spots.
I have found that recipe to work well also.
 

johnjk

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My big ones are multi flora rose, field olives and Japanese milkweed. The first two I’ve had the best luck with pulling them out by the roots with the tooth bar. The milkweed is toxic to the skin and brush hogging does little to keep it down. I may try a controlled burn this summer and see how that does. I don’t hate it enough to invest in chemical eradication plus it is over a 4 acre area. No way to easily spot treat.
 

jyoutz

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Paul,

Thank you for the write up!
I am also battling invasive species on my oak/savanna restoration project in Central Wi.
My main foes are

Spotted Knapweed
Buckthorn
Black Locust
Scot Pines

Unfortunately as you mentioned some of the species can not be eracticated without the use of herbicides.

A issue that is not discussed a lot when I chat with our DNR and habitat organizations is what our neighbors are doing or not doing to keep invasive species controlled. I my case I have spent many $'s and time to try and control Spotted Knapweed but 2/3rds of my neighbors either do not have the resources, knowledge or interest in controlling theirs. With wind born seeds propagating the invasive species this can become a daunting task.

Last summer I had the good fortune to have some help spot treating Spotted Knapweed with a product called Milestone. The help was from an intern finishing up her college courses at one of the University of Wi campus's that offers many DNR and habitat type courses.

Keep fighting the good fight and thanks again for your write-up.

Ken

View attachment 96664
You may not like them, but black locust is a native species in the Midwest and the mid-south.
 
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ken erickson

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You may not like them, but black locust is a native species in the Midwest and the mid-south.
Wisconsin DNR lists black locust as an invasive species. According to their webpage it was introduced into Wisconsin in the early 1900's.
The problem with it here in central Wisconsin is that it will form a monoculture stand and crowd out native Forbs and grasses.

black_locust_brochure.pdf
 

jyoutz

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Wisconsin DNR lists black locust as an invasive species. According to their webpage it was introduced into Wisconsin in the early 1900's.
The problem with it here in central Wisconsin is that it will form a monoculture stand and crowd out native Forbs and grasses.

black_locust_brochure.pdf
I understand why they are considered a pest, just pointing out that the areas I mentioned are their native range. They may not have been historically found in Wisconsin, but they were historically found in adjacent states to the south.
 
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ken erickson

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I understand why they are considered a pest, just pointing out that the areas I mentioned are their native range. They may not have been historically found in Wisconsin, but they were historically found in adjacent states to the south.
One source lists the native range to be these states.

Illinois , southern Indiana, Ohio and Missouri.

I have a friend that has property about 70 miles to the southwest of me, close to Wi Dells. He put in a native planting under the CRP program about 4 summers ago. Had black locust along property line on one side of the planting. It was amazing that within 2 summers the black locust started springing 20 to 50 foot inside the planted natives and reached 8 to 10 foot high in that time. He has now spent time and resources girdling the mother trees.