Do you have the skills to manage residential and commercial landscapes in the most ecologically sustainable ways possible? or know someone who does? Good Oak is looking for a new manager for our Sustainable Landscaping division, learn more about the position here.
Good Oak News
Friday, January 17, 2014
Good Oak is looking for a Sustainable Landscape Manager
Do you have the skills to manage residential and commercial landscapes in the most ecologically sustainable ways possible? or know someone who does? Good Oak is looking for a new manager for our Sustainable Landscaping division, learn more about the position here.
Tuesday, January 14, 2014
Come see us at the Fox Valley Wild Ones Conference!
Good Oak will be in Oshkosh Saturday, January 25th for the Toward Harmony with Nature Conference put on by the Wild Ones - Fox Valley Chapter! This year is going to be extra amazing as Doug Tallamy is the keynote speaker discussing the importance of urban and suburban gardening. It is undoubtedly going to be their biggest conference yet. Sign up now as registration is limited! Plus, the Good Oak booth is going to be stocked this year with all new books, tools, locally made native bee houses, and so much more! We look forward to seeing you there!
For more information or registration details, check out their website at http://www.towardharmonywithnature.org/.
Sunday, October 27, 2013
American Pokeweed: Feast or Foe?
Popping up out of nowhere
We've been working with the Village of Shorewood Hills for a couple years now on rehabilitating a slope that they have set aside as a stormwater control area within the village. By the time we got there in the fall of 2010 it was an area of weedy trees and invasive brush, dominated by a canopy of black locust, with mostly bare soil on the ground. The ground layer plants that were present were mostly invasive species such as burdock, canada thistle, reed canary grass, garlic mustard and dames rocket, but a few scattered patches of native plants remained from the original seeding done in 2000. One thing we did not see when we first started working on the site was American pokeweed (Phytolacca americana).
We've done some regular but limited management work on this slope in the past few years. A prescribed burn, some brush removal, annual control of garlic mustard, dames rocket and other weeds, and a couple rounds of interseeding. Overall the site looks a lot better today, but it's still a work in progress.
The one plant that has responded best to all this treatment is the American pokeweed. It has gone from being absent, or perhaps a small, trivial population, to covering more area on the slope than any other species. It clearly dominates the entire lower 1/3rd of the slope.
This leaves us to wonder, is it healthy to have this much pokeweed? Should we begin to manage pokeweed alongside summer weeds like bull thistle and burdock at this site? I personally have always admired pokeweed as a resilient pioneer species. Its large size, colorful stem and tropical appearance make it an interesting find on any site. But land-managers around southern Wisconsin are becoming concerned about the rapid increase in abundance of this species in their natural areas. I decided to do a little more research on this species to develop an informed decision on how we should approach managing it... as a weed or a native warrior, and I found out some interesting things.
Poison, meal, medicine and dye
It turns out pokeweed is a poison, a medicine, and an edible wild plant, all in one.
The roots, stems, and leaves of this plant contain high amounts of toxic compounds such as phytolaccine, phytolaccatoxin formic acid, tannin, and resin acid. The berries also contain trace amounts of these compounds, which cause diarrhea, colic, bloody stools, possible anemia, and occasionally death. The young leaves contain less toxin and were used as food by Native Americans and early settlers.
Some people still eat this "poke sallet" today by choosing leaves from the plant when the stems are still green (before they turn purple) and boiling them twice, dumping out the water from the first boiling to remove the toxic compounds. The stems can also be cut, covered in cornmeal, and fried like okra (I assume after being boiled once first). According to the site, Eat the Weeds, "Nutritionally, pokeweed is a powerhouse: A half cup of the greens provides 35 calories (10 from fat), no cholesterol, three grams dietary fiber, and 90% of your daily need for vitamin A, 60% of vitamin C, 8% calcium, and 6% of iron." Eat the Weeds has a really good write up about the edibility and cultural impacts of pokeweed consumption so the above link is a worthwhile side trip.
Pokeweed was even sold as a canned vegetable in the southern US until recently. And the popular song from the 1950's, Poke Salad Annie, was written about a poor girl who gathered and ate this plant.
The compounds produced by this plant don't just make the plant difficult to eat, they also have potential use as medicines. Native Americans discovered the medicinal effects of this plant early on and used it to stimulate the heart and to treat cancer, rheumatism, itching, and syphillis. It was also effective as a laxative and to induce vomiting. Compounds found in the pokeweed plant are being examined by modern medical science; particularly the 'pokeweed antiviral protein' (PAP) is being explored for the medicinal value at treating cancer, herpes and HIV. Other compounds in this plant may enhance the immune system and have additional anti-cancer effects. See cancer.org for more fascinating medical info.
On top of all of that, the juice from the berries was once used to make ink and dye, and is still used today to make red food coloring. This pokeweed ink was used by Thomas Jefferson to scribe the Declaration of Independence.
An Ecologically Valuable Plant? Just ask the birds.
The brightly colored berries are an important food source for many songbirds including eastern bluebirds, rose-breasted grosebeaks, cedar waxwings, northern cardinals, hermit thrush and many other birds which typically consume berries, (including, but not limited to these listed on Illinois Wildflowers) as well as small mammals. We noted a pair of cardinals and woodpeckers feeding on the pokeweed at our last visit to the slope.
So What's the Prognosis?
Pokeweed is considered by some to be just a big weed. But its clear that the plant has value feeding wildlife, perhaps on our own dinner plates, and in our medicine. However, it can get overpopulated at times and shade out other more conservative native speices and may need control work to balance the system. It can be particularly overwhelming in small areas. On the other hand, considering the alternatives in such sites are often invasive weeds such as garlic mustard, dames rocket, burdock and thistles, the pokeweed is often a better option than the alternative.
I think the key to this issue in southern Wisconsin is the below image:
Southern Wisconsin is on the very northern edge of the range of this plant, it thrives in warmer, more moist climates to the south and east of here. It's only in the past decade or so that we've been finding it in abundance in southern Wisconsin. It is likely that this insurgence of pokeweed is a result of global warming altering our local weather patterns in such a way that benefits pokeweed. Consider also that the species responds positively to disturbance, and you have a species that we can expect to be common on natural sites into the future. Perhaps there are various parasites and pests that curb the growth and abundance of pokeweed where it is more common further south that will slowly move their way north to slow this species down in our area. Or perhaps due to habitat fragmentation, these potential control agents won't be able to make the trip.
As a point of comparison, American pokeweed has become an invasive plant in some areas of China. According to this study, it is a sucessful invader in forests composed of black locust. Black locust is an invasive plant in Wisconsin. Though native to the southern US, it must have been imported to China for its timber value. It is interesting to note that our work site also has a canopy of black locust, so there appears to be some association between these species. Perhaps pokeweed is immune to the allelopoathic toxins that black locust releases? This would make sense since they evolved in the same environment. The other interesting thing about this study is that they found that where indigo bush, a native leguminous shrub, was found it was able to exclude the pokeweed, though it's not clear why.
So my advice would be to consider doing control work on pokeweed carefully. If you have a lot of other weeds in the area, it appears to be very effective at suppressing plants of shorter stature. There is no garlic mustard under the dense pokeweed patches on our slope in Shorewood. There's nothing else under there either though. So if you have it taking up a lot of space in a habitat surrounded by a lot of more conservative species, then you might want to control it, to speed the process of ecological sucession up a little bit. However, I suspect that a careful inspection of most sites where pokeweed occurs will reveal that pokeweed is the best plant among a list of awful alternatives. I'd speculate that pokeweed wouldn't compete well in more intact habitats against more conservative natives.
My other thought is that if you have a smallish garden, whether it be vegetable, perennial, or both, this species could be a bit too much for your landscape, so removing some or all of the plants makes sense.
If it Must be Done
If you're going to try to control this species, you'll need to know that it forms a large, deep taproot from which it can resprout if cut or only the upper portion of the root is removed. However, if removed when they are still small plants then it's possible to dig them out. The other organic option for control is mowing. However, studies have shown that mowing will knock it back for a growing season, but it will resprout at full strength the next year. So repeated mowing 2-3 times per year for 2-3 years would probably be needed for permanent control.
Glyphosate, the active ingredient in Round-Up® and other common herbicides, has been shown to be effective at controlling this species. But because of the large size of pokeweed it will have to be applied with caution. For a foliar application, the best bet is to get it while the plant is still relatively small in spring to avoid overspray. The other option would be to use a "stump treatment" method, similar to what is used on brush where a 50/50 mix of the glyphosate concentrate and water are mixed and applied directly to a stump immediately after it is cut. This is time consuming but will nearly eliminate any potential for collateral damage. See the label of the herbicide bottle for specific instructions.
We've been working with the Village of Shorewood Hills for a couple years now on rehabilitating a slope that they have set aside as a stormwater control area within the village. By the time we got there in the fall of 2010 it was an area of weedy trees and invasive brush, dominated by a canopy of black locust, with mostly bare soil on the ground. The ground layer plants that were present were mostly invasive species such as burdock, canada thistle, reed canary grass, garlic mustard and dames rocket, but a few scattered patches of native plants remained from the original seeding done in 2000. One thing we did not see when we first started working on the site was American pokeweed (Phytolacca americana).
We've done some regular but limited management work on this slope in the past few years. A prescribed burn, some brush removal, annual control of garlic mustard, dames rocket and other weeds, and a couple rounds of interseeding. Overall the site looks a lot better today, but it's still a work in progress.
The one plant that has responded best to all this treatment is the American pokeweed. It has gone from being absent, or perhaps a small, trivial population, to covering more area on the slope than any other species. It clearly dominates the entire lower 1/3rd of the slope.
This leaves us to wonder, is it healthy to have this much pokeweed? Should we begin to manage pokeweed alongside summer weeds like bull thistle and burdock at this site? I personally have always admired pokeweed as a resilient pioneer species. Its large size, colorful stem and tropical appearance make it an interesting find on any site. But land-managers around southern Wisconsin are becoming concerned about the rapid increase in abundance of this species in their natural areas. I decided to do a little more research on this species to develop an informed decision on how we should approach managing it... as a weed or a native warrior, and I found out some interesting things.
Poison, meal, medicine and dye
It turns out pokeweed is a poison, a medicine, and an edible wild plant, all in one.
The roots, stems, and leaves of this plant contain high amounts of toxic compounds such as phytolaccine, phytolaccatoxin formic acid, tannin, and resin acid. The berries also contain trace amounts of these compounds, which cause diarrhea, colic, bloody stools, possible anemia, and occasionally death. The young leaves contain less toxin and were used as food by Native Americans and early settlers.
Some people still eat this "poke sallet" today by choosing leaves from the plant when the stems are still green (before they turn purple) and boiling them twice, dumping out the water from the first boiling to remove the toxic compounds. The stems can also be cut, covered in cornmeal, and fried like okra (I assume after being boiled once first). According to the site, Eat the Weeds, "Nutritionally, pokeweed is a powerhouse: A half cup of the greens provides 35 calories (10 from fat), no cholesterol, three grams dietary fiber, and 90% of your daily need for vitamin A, 60% of vitamin C, 8% calcium, and 6% of iron." Eat the Weeds has a really good write up about the edibility and cultural impacts of pokeweed consumption so the above link is a worthwhile side trip.
Pokeweed was even sold as a canned vegetable in the southern US until recently. And the popular song from the 1950's, Poke Salad Annie, was written about a poor girl who gathered and ate this plant.
The compounds produced by this plant don't just make the plant difficult to eat, they also have potential use as medicines. Native Americans discovered the medicinal effects of this plant early on and used it to stimulate the heart and to treat cancer, rheumatism, itching, and syphillis. It was also effective as a laxative and to induce vomiting. Compounds found in the pokeweed plant are being examined by modern medical science; particularly the 'pokeweed antiviral protein' (PAP) is being explored for the medicinal value at treating cancer, herpes and HIV. Other compounds in this plant may enhance the immune system and have additional anti-cancer effects. See cancer.org for more fascinating medical info.
On top of all of that, the juice from the berries was once used to make ink and dye, and is still used today to make red food coloring. This pokeweed ink was used by Thomas Jefferson to scribe the Declaration of Independence.
An Ecologically Valuable Plant? Just ask the birds.
The brightly colored berries are an important food source for many songbirds including eastern bluebirds, rose-breasted grosebeaks, cedar waxwings, northern cardinals, hermit thrush and many other birds which typically consume berries, (including, but not limited to these listed on Illinois Wildflowers) as well as small mammals. We noted a pair of cardinals and woodpeckers feeding on the pokeweed at our last visit to the slope.
So What's the Prognosis?
Pokeweed is considered by some to be just a big weed. But its clear that the plant has value feeding wildlife, perhaps on our own dinner plates, and in our medicine. However, it can get overpopulated at times and shade out other more conservative native speices and may need control work to balance the system. It can be particularly overwhelming in small areas. On the other hand, considering the alternatives in such sites are often invasive weeds such as garlic mustard, dames rocket, burdock and thistles, the pokeweed is often a better option than the alternative.
I think the key to this issue in southern Wisconsin is the below image:
 |
| Image courtesy: Kartesz, J.T., The Biota of North America Program (BONAP). 2013. Taxonomic Data Center. (http://www.bonap.net/tdc). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2013. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)] |
Southern Wisconsin is on the very northern edge of the range of this plant, it thrives in warmer, more moist climates to the south and east of here. It's only in the past decade or so that we've been finding it in abundance in southern Wisconsin. It is likely that this insurgence of pokeweed is a result of global warming altering our local weather patterns in such a way that benefits pokeweed. Consider also that the species responds positively to disturbance, and you have a species that we can expect to be common on natural sites into the future. Perhaps there are various parasites and pests that curb the growth and abundance of pokeweed where it is more common further south that will slowly move their way north to slow this species down in our area. Or perhaps due to habitat fragmentation, these potential control agents won't be able to make the trip.
As a point of comparison, American pokeweed has become an invasive plant in some areas of China. According to this study, it is a sucessful invader in forests composed of black locust. Black locust is an invasive plant in Wisconsin. Though native to the southern US, it must have been imported to China for its timber value. It is interesting to note that our work site also has a canopy of black locust, so there appears to be some association between these species. Perhaps pokeweed is immune to the allelopoathic toxins that black locust releases? This would make sense since they evolved in the same environment. The other interesting thing about this study is that they found that where indigo bush, a native leguminous shrub, was found it was able to exclude the pokeweed, though it's not clear why.
So my advice would be to consider doing control work on pokeweed carefully. If you have a lot of other weeds in the area, it appears to be very effective at suppressing plants of shorter stature. There is no garlic mustard under the dense pokeweed patches on our slope in Shorewood. There's nothing else under there either though. So if you have it taking up a lot of space in a habitat surrounded by a lot of more conservative species, then you might want to control it, to speed the process of ecological sucession up a little bit. However, I suspect that a careful inspection of most sites where pokeweed occurs will reveal that pokeweed is the best plant among a list of awful alternatives. I'd speculate that pokeweed wouldn't compete well in more intact habitats against more conservative natives.
My other thought is that if you have a smallish garden, whether it be vegetable, perennial, or both, this species could be a bit too much for your landscape, so removing some or all of the plants makes sense.
If it Must be Done
If you're going to try to control this species, you'll need to know that it forms a large, deep taproot from which it can resprout if cut or only the upper portion of the root is removed. However, if removed when they are still small plants then it's possible to dig them out. The other organic option for control is mowing. However, studies have shown that mowing will knock it back for a growing season, but it will resprout at full strength the next year. So repeated mowing 2-3 times per year for 2-3 years would probably be needed for permanent control.
Glyphosate, the active ingredient in Round-Up® and other common herbicides, has been shown to be effective at controlling this species. But because of the large size of pokeweed it will have to be applied with caution. For a foliar application, the best bet is to get it while the plant is still relatively small in spring to avoid overspray. The other option would be to use a "stump treatment" method, similar to what is used on brush where a 50/50 mix of the glyphosate concentrate and water are mixed and applied directly to a stump immediately after it is cut. This is time consuming but will nearly eliminate any potential for collateral damage. See the label of the herbicide bottle for specific instructions.
Monday, October 7, 2013
Job Opening: Ecological Restoration Manager
Good Oak Ecological Services is looking for qualified candidates to fill our Ecological Restoration Manager position here at our Madison location. This position is responsible for supervising all aspects of Good Oak's ecological restoration projects, including meeting with clients and educating them about the ecological health of their property, formulating feasible adaptive management plans, developing estimates and proposals, leading the crew conducting field work, and invoicing completed projects. Our restoration work includes: brush removal, prescribed burning, mechanical and chemical weed control, prairie establishment, shoreline and slope restoration, and erosion control.
For more information see the job announcement on our website:
http://goodoak.com/RestorationManager2013.pdf
For more information see the job announcement on our website:
http://goodoak.com/RestorationManager2013.pdf
Wednesday, August 28, 2013
Native Thistles: Pillars of the (Natural) Community
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| A great spangled(?) fritillary butterfly enjoying some nectar from a native pasture thistle. |
Yesterday I took the crew out for a field day to some great natural areas so they could learn some plants and see what real, healthy, managed prairies and savannas look like. Along the way we were fortunate enough to see a lot of native thistles in bloom. We saw many butterflies and bees feeding on these thistles, and I explained to them that, in addition to being excellent pollinator plants, the seeds were valuable food sources for small birds (goldfinches love thistles) and that the fluff from thistle seeds is used by hummingbirds and other small birds for nesting materials. Later, researching online I found that goldfinches are so enamored with thistles that seeing them actually has an effect on their hormone levels.
Then last night I read this article about the reintroduction of the rare swamp metalmark butterfly into a restored wetland in the Chicago area. It turns out the swamp metal mark caterpillars can only eat our native swamp thistle and pasture thistle. These valuable members of our local natural community have a lot to offer, but unfortunately they have suffered not only from habitat loss that effects all of our native species, but also from persecution due to their similarity to the weedy exotic thistles.
Exotic Thistles: America's Least Wanted
Most people think of thistles only as weeds. And it's true that some of most common, troublesome and difficult to eradicate weeds include Canada thistle, plumeless thistle, bull thistle, and musk thistle. These are all exotic species, introduced accidentally as agricultural weeds which are now problems in cultivated and natural areas alike. There are a few more exotic, weedy thistles too, such as European marsh thistle, but they are less common in this part of the state. In any event, these weedy thistles have long been recognized as pests and are on top of many noxious weed lists. There are only 3 plant species listed under Wisconsin's noxious weed law and one of them is Canada thistle.In Illinois, both Canada thistle and musk thistle are listed as noxious weeds (not sure why they skipped the more common bull thistle), and they only bothered to put 7 other plant species on this list. Canada thistle is in fact listed as a noxious weed in 43 states!
When we at Good Oak are managing natural areas we always make controlling thistles a priority. Every farmer has a deep seated hatred of thistles, and we don't want people thinking our prairies are just 'weed patches'. Because of this common disdain for thistles, and some local weed laws (more on this later) native thistles are rarely included in commercial prairie seed mixes, despite the many benefits they can offer to wildlife.
Native Thistles: Rare Natural Gems
Wisconsin has five native thistles. Let me introduce you to them:Pasture thistle (Cirsium discolor) is found in mesic prairie remnants, and sometimes more disturbed sites like woodland edges and yes, even pastures. You will occasionally find it in some better quality restored prairies.
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| Pasture thistle flower. |
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| Pasture thistle. |
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| The pale underside of the leaf on pasture thistle. |
It looks a little like bull thistle at first glance, but the underside of the leaf is distinctively white, which is where this species gets its scientific name. A lot of overlapping silvery hairs create this bright white appearance. Bull thistle can be pale on the underside, but if you're looking at pasture thistle you will definitely think "whoa, that's white!"
Tall thistle (Cirsium altissimum) is a plant of open woodland and savannas. Note that the leaves aren't very thistle like with only small thorns. In fact, without the flowers you might not think it was a thistle at all. They have more surface area to gather more light in these semi-shade environments. The stems are covered in fine hairs, and tall thistle shares the white leaf undersides with its cousin pasture thistle.
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| Tall thistle. |
Swamp thistle (Cirsium muticum) grows only in good quality wetlands. The flowers are a darker, more vivid magenta color compared to most other thistles.
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| Swamp thistle. |
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| Swamp thistle flower. |
Hill's thistle (Cirsium hillii) is a state threatened species which you which you will only find in dry sandy prairies in the upper midwest. It's our shortest native thistle, typically around 18". It's also densely hairy to help it retain moisture in its dry sand-prairie habitat. The flower color is more of a true pink rather than magenta, even reddish.... unfortunately my poor-quality cell-phone photo below is not color accurate.
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| Hill's thistle. |
Dune thistle (Cirsium pitcheri) is our rarest thistle, so rare in fact that it is Federally Threatened. It only grows on a handful of sites in Wisconsin, on stabilized sand dunes on the Lake Michigan shoreline. Its range is limited to the Great Lake shorelines of Wisconsin, Illinois, Indiana and Michigan, within a few-hundred feet from the shore. Its flowers are a pale pink, and its foliage looks nothing like other thistles with hardly a thorn to be seen. In fact the frosted-grey looking leaves look more like sage than any thistle.
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| Dune thistle flower. |
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| Dune thistle's basal rossette (foliage). |
Thistles: Nature's Grocery Store
As it turns out, thistles are extremely valuable plants to wildlife. Most of us think of flowers and we think of pollinators, and thistles are extremely attractive flowers to many kinds of bees, butterflies, hummingbirds, hawk moths, and many, many other small creatures. Spiders, assassin bugs and other predators set up shop on thistle flowers; pollinators can't resist the flowers so they are great spots to ambush prey. |
| Two species of bumble bee and dozens of small green beetles collect nectar and pollen from a pasture thistle. |
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| As much as it pains me to admit it, this Delaware skipper is enjoying a nectar drink from a Canada thistle. Even the exotic invasive thistles can provide some value for wildlife. |
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| Butterflies love thistles. Fritillary butterflies like this one seem to be particularly enamored by flowers in this genus. |
In addition to pollinators and the predators who love them, many insects feed on the foliage of thistles, such as the above mentioned swamp metal mark butterfly. Some of these insects are specialists that can only feed on thistles and no other food source. Others are more generalist and can feed on other, similar plants. John Hilty from Illinois Wildflower has put together this list of insects that feed on thistles on his amazing website.
With at least 23 species of insects that feed on the foliage and (I don't think I'm going out on a limb here to say) hundreds of insects (and one bird) that feed on the nectar and pollen, you can see they play an important role in our ecosystem. Even more so if you consider all the insects, spiders, amphibians, reptiles, mammals and especially birds that in turn feed on the insects that feed on the thistles. Thistles aren't only a pillar of the natural community, they are a big part of the foundation of the natural food pyramid.
Separating Good from Bad:
Our noxious weeds laws are put in place for a reason. These weeds cause economic and ecological damage. Canada thistle in particular is extremely difficult to eliminate requiring an expert, targeted approach for success. But to be absolutely clear, none of our native thistles are aggressive, weedy species. They will not spread rapidly like Canada thistle or infest over-grazed pastures like bull thistle or plumeless thistle. They really can't tolerate the heavy disturbance associated with modern agriculture and dairy production and pose no threat of economic loss to farmers. Unfortunately, many weed laws treat all thistles the same, outlawing the exotic weeds and the already imperiled native thistles alike.For example, the City of Madison's weed ordinances which can be found in Chapter 23, section 29, paragraph 2 states that “The term 'noxious weeds' as used in this section includes the following: Canada or other thistles...” while leaving out many more harmful weeds such as, oh, I don't know, just about everything listed on the state of Wisconsin's invasive species rule NR-40.
The state of Iowa lists any and all all plants in the Cirsium and Carduus genera (what we might call all of the true thistles) as noxious weeds, regardless of origin. At least Iowa is thorough in its noxious weed list to include harmful invasive plants like purple loosestrife, common buckthorn and poison hemlock among others. By comparison Madison's weed ordinance seems somewhat haphazard.
I don't have much say in Iowa or in other municipalities around the midwest that throw a blanket ban on any thistle of any kind, but I would like to help make an effort to improve Madison's noxious weed law. If we can be clear about what plants are an economic, ecological and/or health threat to our citizens then we come up with a sound list of plants that should be banned in our community. The state's NR-40 list is a good place to start. Throw in a few hazardous plants that are already on the list such as poison ivy and the ragweeds, throw in a special request for reed canary grass which has some economic value, but is an ecological horror show, and I think we would have a good law. Then if only we could get the city to enforce it...
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