- Everything You Need to Know About How to Get Rid of Pokeweed
- Things You Will Need to Get Rid of Pokeweed
- How to Get Rid of Pokeweed
- Pokeweed and giant ragweed: Common look-alikes to giant hogweed
- Pokeweed, Phytolacca americana
- Life Cycle
- Flowers and Fruit
- Roots and Underground Structures
- Distinguishing Features
- Popular Culture
- Medicinal uses
Everything You Need to Know About How to Get Rid of Pokeweed
Pokeweed is one of the hardest weeds to control or kill. They are a nuisance to gardeners everywhere. Pokewood, or Phytolacca Americana, is a perennial herb that grows in U.S. plant hardiness zones 2 through 11.
Many gardeners want to learn how to get rid of pokeweed, only to realize that it is a never ending process!
Birds help to propagate new plants by dropping seeds after eating them. Also, seeds fall off the plant. One pokeweed plant can produce 50,000 seeds in a lifetime.
Each seed can last for 40 years. These are some of the reasons why the pokeweed invasion is so hard to control! Pokeweed and cockroaches could both survive the apocalypse.
Everything You Need to Know About How to Get Rid of Pokeweed
You can find pokeweed almost anywhere in the United States. It is a native plant that grows in disturbed soils like fields and pastures.
However, you can find them almost anywhere. Unfortunately, pokeweed is hazardous to livestock. All parts of the pokeweed plant are considered toxic.
Identifying pokeweed is quite easy, and you will likely see it each year. It has a red, woody stem with oval leaves. These leaves can reach up to ten inches long!
July to September, the pokeweed has green flowers and has grape-like clusters of berries. The plant is quite deceiving; the berries look edible but don’t dare try them! They can lead to some unpleasant reactions.
One of the reasons you need to get rid of pokeweed is that children could try to ingest the berries. They look delicious, and children are naturally curious.
Typically, eating a berry or two won’t kill you. It is full of toxic compounds, dangerous for children. While the roots are the most toxic choice, every part of the plant has some toxicity.
Things You Will Need to Get Rid of Pokeweed
- Garden hoe
- Bow rake
- Optional – Glyphosate herbicide
How to Get Rid of Pokeweed
There are a few methods for getting rid of pokeweed. Most people use a combination of these methods when they learn how to get rid of pokeweed..
Unfortunately, you will always have to keep up with the process of removal and always keep an eye on the inflicted area.
1. Remove small, new shoots by hand
Don’t just pull on the top of the plant. You have to firmly grab the plant at the base and pull straight up. When you do this, think about harvesting a carrot.
If you do it correctly, a thick taproot with a thin root will emerge from the soil. This method works best in light soil; clay soil compacts easily, making it harder to remove the roots.
2. Manual removal of larger pokeweed plants
For larger plants, pulling it up by base won’t work as well. Manual removal requires you to dig deeply to get out of the taproot.
You will want to dig a circle around the base of each plant. The hole should be 12 inches in diameter and depth. Using a spade will make this job much easier.
3. Use your tools to get the plant loose
Pokeweeds don’t want to come out of their comfortable home in the soil. Don’t expect to remove the plant without some muscle work.
One of the best methods to remove the plant once you dig the hole is to use your spade to pry it loose from the group. You want to get the entire root from the hole. Otherwise, it will grow back too quickly.
4. Loosen the soil with a rototiller
Once you have manually removed all of the pokeweed plants in the desired area, you need to get all of the loose root pieces.
The last thing you want, after all of this hard work, is for the plants to grow back. A rototiller can churn up the soil to a depth of 12 inches. Then, use a rake to go through the turned up soil, looking for root pieces.
5. Sun the pokeweed to kill them off
If you just throw the pokeweeds over to the side, you will likely find a regrowth in that area. You want to get rid of them totally!
Place the pokeweed plants on an area away from the soil, such as on a tarp or a work surface. They need to be left in the sun to dry out and die.
Once they are thoroughly dried and dead, you can put them into a compost bin or a waste bin. Never put them in your compost bin before they are fully dried!
6. Frequent maintenance removal is crucial
You will have to continue this process. It is important for you to pay attention to the area.
If you notice new shoots or plants emerging from the ground, pull them up as fast as possible. Seeds have a long viability span. There is a good chance they will eventually reemerge.
7. Use glyphosate herbicide for persistent problems
Sometimes, you have to resort to an herbicide to entirely get rid of the pokeweeds. Take the top of the shoots and put them into a bottle with two or three percent glyphosate herbicide.
This method helps the stem suck up the chemicals, taking it directly to the roots. You will find this approach is useful for persistent problems that seem to have no end.
You need to keep the top of the shoot into the solution for two days. Or, you can apply it to the leaves of the plants. Then, you have to pull or dig up the plant after ten days.
Victims of pokeweed find that they must continue this process every year. Thankfully, the patch will eventually get smaller with dedication and a lot of digging.
It is important to remove all of the new shoots you find. You have to get the entire root out of the ground, or they will return.
For the larger plants, you need to dig a large hole around the plant and pry the plant out of the soil. Remember always to dry out the plants before disposing of them! These vicious plants are hard to eradicate, but you will be victorious eventually.
They pop up quickly, like an alien invasion in our yards.
They spread downward through the soil as quickly as they grow upward. The invasion is so widespread that you may see it anywhere you go, if you are tuned into it. This intruder is just as poisonous as it is prolific, causing symptoms that could easily kill an adult human. The invader’s name is simple and well known: pokeweed.
Phytolacca americana, aka pokeweed, is indeed a weed — and a feisty one at that. With a taproot that is almost impossible to dig up, berries that will stain anything, and poison coursing throughout the whole plant, it can be quite scary. So, why are many people letting this perennial weed grow in their yards? Maybe it’s the pretty purple berries or the nice fall color it shows, or maybe they just don’t know what they have on their hands.
Pokeweed does have a few positive attributes. In the book “Weeds, Friend or Foe?” author Sally Roth contemplates the value of this fruitful intruder. She mentions the fact that it is a great source of nutrition for berry-eating songbirds. She also speaks of the uses in wildlife gardens, writing that “the purple stems are outstanding with the bleached ornamental grasses in fall,” which sounds quite appealing.
While all that is well and good, the cons certainly outweigh the pros in many ways. Birds can spread this weed like wildfire by carrying the seeds, and pokeweed will grow anywhere, sun or shade. So wherever a berry is dropped, you can bet a new plant will pop up next year.
Roth explains that pokeweed is poisonous and, if consumed, can kill an adult human very fast. Symptoms of pokeweed poisoning, according to Kansas State University, include abdominal cramping, diarrhea, vomiting, weakness, drowsiness and difficulty breathing. Children may be attracted to the toxic berries, and the plant is also dangerous to animals.
Pokeweed has actually been eaten for hundreds of years, but only through a process that includes boiling the leaves for a long period of time while replacing the poison-filled water several times before consuming. It is said to have a taste similar to spinach, but you won’t catch me trying it and letting you know!
If you happen to find pokeweed in your yard, it will become a chore to pull it up. These plants have very long taproots that can also be very wide, sometimes reaching close to 6 inches in diameter. That entails quite a lot of work.
Roth has several suggestions, including digging the plant up, then digging as far into the root as possible and pulling it all out. Another suggestion is what I do, which is cruise my yard regularly and pull out the little seedlings by hand, before they can grow up. Yet another suggestion from Roth is to use a hoe and “scrape the flocks of seedlings with a swipe of the hoe blade just below the surface of the soil.”
Pokeweed can also be killed by chemicals. According to a study done by Perdue University, Roundup seems to be the most effective at killing pokeweed in the home landscape. Be aware that Roundup will kill anything herbaceous in nature, so if you are spraying pokeweed, you will also be spraying other plants near it.
The benefits of pokeweed are not really enough to justify keeping this plant in your landscape. It is dangerous if eaten and it is highly invasive. If you find it growing in your soil, take steps to destroy it as soon as possible for your family’s protection and the safety of your whole neighborhood.
More on the blog: blogs.roanoke.com/fanaticalbotanical
Pokeweed and giant ragweed: Common look-alikes to giant hogweed
Every late spring and early summer when plants suddenly put on a great deal of growth because of extra rain, some people become worried. Could those big plants be the dreaded giant hogweed they have heard about? Many calls come into Michigan State University Extension with questions and concerns.
It is possible to go online and search for “giant hogweed look-alikes” and find a number of sites, but these are usually just rehashing the same plants, and not all big plants are covered. People are concerned because they have discovered big plants they cannot recognize. They sort of remember parts of the giant hogweed description, like purple stems and large leaves or hairs on stems. When their heart starts to race, the rest of the description is forgotten. Pokeweed and giant ragweed are two Michigan plants that have attracted attention by being similar in the viewer’s eyes.
Phytolacca americana is a perennial native plant. Pokeweed can grow 9-12 feet tall under good conditions. Stems are smooth and soft green when the plant is young. As the plant grows and stems age, they are uniformly reddish or soft purple and are relatively smooth. There may be a single stem or multiple stems. Leaves are green and smooth with a plain margin. Leaves are slightly egg-shaped with a pointed tip and have an alternate placement to each other on the stems.
Pokeweed is currently blooming with small white and green blossoms, often showing a soft pink color. The flowers will become dark purple berries that are reminiscent of a loose cluster of grapes. All parts of the plant are toxic for people to eat, but birds and other critters relish the berries. Young plants were boiled several times and eaten in some places in the south, and this was called “poke sallat or poke salad.” The berries have a crimson juice that in the past was used for dyes. The plant produces a massive taproot that is often branched as the plant matures. Native Americans used this plant for medicinal purposes as a purgative.
- Want to love it? Pokeweed is a large, majestic plant with virtually no insect, disease or animal problems. It can add an impressive presence to a native landscape.
- Want to hate it? In the fall, birds feed on the ripe berries and then fly directly over your car, leaving multiple purple to crimson birdie-bloops on the vehicle.
Pokeweed stems are uniformly reddish or soft purple as they age. Photo by Patrick Voyle
Ambrosia trifida is an annual plant with its origins in Europe. It reproduces by seeds. Stems are coarse, rough, hairy and slightly ridged. It can grow to 12-18 feet tall on rich, moist soils. Leaves are opposite of each other on the stem and have three pointed lobes, but occasionally five lobes. Leaves have a subtle, serrated edge. There are two kinds of flowers, male and female, on the plant. They grow in spikes at the end of branches and bend over slightly.
- Want to love it? Giant ragweed is a rank weed that only its mother could love unless one is into the unkempt jungle look.
- Want to hate it? This is the plant that causes much of the hay fever misery for people because of its abundant pollen. This is light floating pollen. Goldenrod has heavy pollen that pretty much drops like rocks and almost never is the Allergy King of the Prairie.
Giant ragweed leaves. Photo by Debbie White
Smart gardeners have already checked out giant hogweed websites and the really smart ones have purchased books so they can identify plants on their property. For more help in identifying common giant hogweed look-alikes, see “Common plants are being mistaken for giant hogweed.” For photos and more information of giant hogweed, see “Giant hogweed: Not widely spread in Michigan.”
My Backyard Poison: Pokeweed
I have a weed in my backyard. Every year, for the past 7 years, it has poked its head from the fertile soil in the border between the yard and the woods, looking oh-so cute and innocuous. Then I blink. Next thing I know, its nearly six feet tall with an equally wide canopy, covered with clusters of small, white flowers that soon develop into green berries that ripen over the summer to a deep, dark purple. Plants have a tendency to grow fast and wild here in the hot and humid South, so in late summer I’ll hack it down, which is surprisingly easy, given its size. There’s a small tinge of remorse, but after I clear out the wild vines and plants that have overtaken the neutral-zone I feel satisfaction. Throughout the fall and winter I sit at the kitchen table, remarking how nice and clean the area looks, all the while knowing that it is short lived. I blink again, and it’s early summer, and the weed emerges yet again. Its a fun little game we play, and I’ll miss it if it fails to return one year. But only for a small while, I only have room for one feeling at a time.
The weed I refer to is pokeweed, Phytolacca americana, an herbacious perennial plant, which explains why it’s so easy to cut down (non-woody) and comes back every year. It grows throughout the United States, and particularly the southeast, where it is literally everywhere. Along ditches, on the side of road, in open fields. Everywhere. But is it really a weed? I often read that a weed is just a plant that we haven’t figured out what to do with yet, so in that regard, pokeweed is certainly not a weed. In fact, pokeweed is edible. It’s also poisonous. It’s a poisonous edible that is deadly and delicious. Confused? Not for long.
Pokeweed is edible and relatively safe . . . if you know what you’re doing.* First, the thick taproot and immature green berries should never be eaten. The young leaves and shoots are edible, so long as you pick them while they are small – plants less than 8 or so inches tall – and you boil them twice, changing the water each time. Mature leaves, or from plants that have red-tinted stalks, despite their size, should never be ingested either. It sounds like a lot of work to me, but people have been doing it for centuries. Hell, even Elvis sang about it.** Swamp rock pioneer Tony Joe White, who wrote the song, covers it much, much better than The King, though.
* I don’t know what I’m doing. It’s likely you don’t either. So if you feel an insatiable need to forage, find a local expert.
** Pokeweed is called Polk in some areas, after the 11th U.S. president James Polk. I’m sure you don’t care.
So what happens if you don’t follow these rule? Incredible sickness. Violent nausea, vomiting, diarrhea, and urinary incontinence may be the least of your worries. Convulsions, transient blindness, and syncope (loss of consciousness due to low blood pressure) are of more serious concern. Scratch that…move crapping your pants over to the serious side.
It is these effects though, that have made pokeweed a folk medicine. Teas made of roots and leaves have been used for centuries as an abortificant, a treatment for syphilis and scurvy, and a remedy for rheumatism. Early settlers learned of pokeweed from the Algonquin and Cherokee tribes, who also used the ripe berries as a dye for arrows and horses. In fact, pokeweed received its name from the Algonquin word “pakon,” meaning dye. Since it is so plentiful, pokeweed ink was commonly used, and many Civil War letters were penned with the ink. Here in Appalachia country, pokeweed is still used today as a “blood cleaner,” and prepared by cooking in hot grease – probably bacon. In a nutshell, if there’s something in your body that you want out, pokeweed is the right tool for the job.
In Tennessee, a 68 year-old man was found by his wife sweating profusely, drooling, vomiting, and without any control of his bladder or bowels, before becoming unconcious. At the ED everything was basically normal, save for a blood pressure of 75/54 mm Hg and general weakness with inability to stand. Liver enzymes, ECG, CT scans, and “the works” were normal, and by the following day the patient was fine and discharged.
What caused this man’s insides to want to go outside? Pokeweed. He was suffering from a bout of constipation and remembered what his mother would make when he was a child: pokeweed tea. He picked pokeweed leaves and stems from a plant in his yard and boiled them up. He placed the concoction in the refrigerator for several days, until he was tempted by the ice-cold liquid on a hot, sunny day. Ten minutes later, fluids were exploding from every orifice. Safe to say, he was cured of constipation.
What devilish chemical, or chemicals, are responsible for this, and why would nature do this to us? Phytolaccatoxin is thought to be a main contributor, as well as various saponins – similar to solanine in green potatoes. There are countless other natural products, but given pokeweed’s history and cultural significance, there is surprisingly little known about them. I would be remiss, however, if I failed to note that there are multiple studies investigating the naturopathic properties of pokeweed, for indications such as cancer and HIV. Nothing has panned out, but hopefully these last two sentences will cut down on the deluge of emails I get from angry readers. Yes, even I get hate mail.
From the symptoms of our older gentleman, there seems to be a cholinergic effect with pokeweed, stimulating the parasympathetic nervous system, which you all remember as SLUDGE:
☑ Defecation (or Diaeresis)
☑ GI upset
He wasn’t crying, or at least it wasn’t reported…but I bet he wanted to. What is clear, however, is that pokeweed is not to be taken lightly, and despite its edibility, special procedures and precautions must be followed. All you residents, fellows, and ED doctors in the South take note! And remember, Mother Nature has planted poisons everywhere, even my backyard.
This is a follow up article to a blog that my colleague, Guy Kyser wrote back in 2011 titled “Purple alert: Common Pokeweed”. Since that time, I probably get a dozen or so calls this time of year asking, “what is that huge weed growing in my yard with dark black berries and big green leaves.” Pokeweed!
I personally find this plant quite interesting. As a native to portions of the United States, it turns out this plant has a diverse history and in recent years it is being studied in cutting edge medical research and energy technology. Have I perked your interest? If so read on.
American pokeweed (Phytolacca americana) is a robust, non-woody shrub that is weedy throughout much of California. Native to the eastern United States from Maine to Wisconsin, south to Texas, Mexico and Florida, pokeweed now occurs throughout much of North America. It is sometimes cultivated as an ornamental or garden vegetable, however more often it’s considered an undesirable weed. Pokeweed is found in riparian areas, oak woodlands, forest edges, fence rows, forest openings, pastures, under power lines, disturbed areas, vineyards, orchards, cultivated fields, parks, and ornamental landscapes.
Common pokeweed (Phytolacca americana) Also called poke salad, poke sallet, pokeberry, inkberry, American nightshade, American spinach, scoke, and pigeonberry, the plant’s uses are as diverse as its names. Pokeweed has an extensive history for being used as a food, medicine, herb, dye for clothing, ink for writing, colorant for wines, and much more. Although used for food, extreme caution should be used, as the entire plant is poisonous causing a variety of symptoms, including death in rare cases.
Pokeweed is an erect herbaceous perennial shrub, 4 to 10 feet tall and 3 to 5 feet wide, with large leaves and showy purple-black berries. It has a smooth, stout, purplish stem that branches extensively and can reach up to 2 inches in diameter. The bright green, elliptic leaves are smooth, tapered, and alternate on the stem. Leaves can be large, reaching up to a foot in length and 4 to 7 inches wide and have a strong unpleasant scent when crushed. The purple berries hanging from the bright green leaves and red stems in late summer are the most distinguishing characteristic of pokeweed.
Reproduction is by seed and a single plant can produce 1,500 to 7,000 seeds annually. The seeds are large, lens-shaped, glossy, and black. Seeds can remain viable in the soil for up to 50 years. Pokeweed berries serve as an important food source for many species of birds, including Robins, Cedar-waxwings, Warblers, pigeons, and many others. New populations of pokeweed are spread primarily by birds. Seeds germinate in mid spring through early summer when soils are warm and moist. Germination is followed by rapid growth.
Pokeweed flowers in mid-summer. Flowers are borne in white-pinkish clusters that hang from the branches. Flowers consist of 5 white sepals, no petals, and are erect when in bloom and begin to droop as fruits develop. Flowers are self-fertile resulting in high fruit set. Immature berries are dull green, turning glossy purple-black at maturity in late Summer.
Pokeweed’s above-ground growth dies back after the first Fall frost, leaving large skeletons that breakdown over the winter. In the Spring, plants resprout from a large fleshy taproot.
Common pokeweed storage root
Pokeweed is an occasional weed throughout much of the United States and is increasing in abundance in some areas. Once seen as a wildland weed, pokeweed is now becoming more common as an urban and landscape weed. All plant parts, especially the roots, contain numerous saponins and oxalates and can be fatally toxic to humans and livestock when ingested raw or with improper preparations. Severe digestive tract irritations are the primary symptom.
American pokeweed has a long history in the United States. A wide variety of chemicals have been isolated from pokeweed that have medicinal properties and Native Americans have used the plant in herbal remedies for centuries. During the Civil War, soldiers wrote letters using the ink from American pokeweed berries, and the pigment is still used occasionally to dye fabrics. Pokeweed has also been a favorite staple of country cuisine since colonial times, when tender young shoots were boiled and eaten as “poke salad”. Resembling canned spinach, “Poke salad” or “Poke sallet” was once available commercially and still inspires “Poke” festivals across portions of the east coast and the Deep South. American singer-songwriter and guitarist, Tony Joe White is best known for his 1969 hit song “Polk Salad Annie”, that was performed by Elvis Presley and Tom Jones. The shoots proved so popular to the first European explorers to the New World, it is documented that early Europeans took the sprouts back to Europe where they were equally enjoyed.
While Pokeweed has been used in folk medicine to treat numerous health problems and is still used in many herbal remedies today, medical research has not shown whether pokeweed is indeed effective in treating many of these ailments. Recently a protein in the plant “pokeweed antiviral protein” shows promise in being used in treating cancer, herpes, human immunodeficiency virus (HIV), and for conferring broad spectrum disease resistance in agricultural crops.
Researches have also been examining pokeweed for other uses. The dark red dye made from pokeweed is currently being tested to coat fiber based photovoltaic solar cells. The dye acts as an absorber, helping the cells tiny fibers trap more sunlight to convert into power. This fiber cell technology can produce as much as twice the power that current flat-cell technology can produce, and the dye made from pokeweed is much less expensive than a polymer dye.
What’s in a name. The scientific name Phytolacca americana comes from the Greek word phyton meaning plant and lacca meaning crimson lake in reference to the deep reddish-purple fruits. The second term, americana is in obvious reference to this plant being native to America. The common name poke is derived from puccoon, pocan or poughkone (from an Algonquin Indian name for this plant). Berries were once used to make ink, hence the sometimes-used common name of inkberry. An additional common name is poke sallet, local term meaning salad.
Pokeweed is spread by seed and new occurrences are often were birds frequent. Monitoring for new seedlings in areas below tree canopies, along fence rows, and below other perches, often provides the best strategy for surveillance and early detection.
Hand pulling is effective on small plants. Once plants are established and develop an extensive root system, hand removal is difficult. Digging out established plants with a shovel is effective, but often difficult in summer when soils are dry. Cutting well below the root crown prevents regrowth. Cultivation can also be effective on new seedlings in raised beds or other areas where tilling can be used.
Grazing is not considered an effective control option and animals should not be encouraged or allowed to consume large quantities of pokeweed. Seeds and foliage contain numerous saponins and oxalates and can be fatally toxic to livestock when ingested.
There are no biological control agents currently available for the management of pokeweed.
Foliar Sprays. The effectiveness of herbicides applied to the foliage depends on three factors—timing, achieving good coverage, and concentration.
Timing. Foliar application of herbicides to pokeweed is most effective after leaves are fully developed and when the plant is actively growing. This period normally is from April into July or August, when soil moisture remains adequate.
Don’t apply herbicides before plants begin their spring growth or in late fall when plants are stressed.
Although not typically a problem, dust can cover plants growing near roadsides. Herbicides, particularly glyphosate, can readily attach to dust or soil particles, thus reducing their effectiveness.
Coverage. You can apply herbicides as a foliar spray using one of two methods. The first is spray-to-wet, where all leaves and stems should glisten following an application. Coverage, however, should not be to the point of runoff.
The other method is a low-volume foliar application called drizzle. This technique uses a higher concentration of herbicide, but you spray it at a lower volume. This method is advantageous in dense shrubbery or where access is limited. To achieve proper coverage, spray the herbicide uniformly over the entire canopy in a “drizzle” pattern, using a spray gun.
Concentration. For spray-to-wet applications, products containing at least 41% glyphosate as the active ingredient can provide good to excellent control of pokeweed when applied at 3.75 ounces of product per gallon of water (3% of the total solution). Some products available for use in the home landscape with this concentration of active ingredient are Roundup Pro Concentrate®, FarmWorks Grass & Weed Killer 41% Glyphosate Concentrate, RM43 Total Vegetation Control, Compare-N-Save Grass & Weed Killer Concentrate, and Remuda® Full Strength. Glyphosate products that have a lower concentration of active ingredient, such as Roundup Weed & Grass Concentrate (18% active ingredient), will require about 6 ounces of product per gallon of water (4.7% of the total solution) for effective control.
Triclopyr is available in either amine or ester formulations, with triclopyr ester being more effective on pokeweed. Products containing a minimum of 61% active ingredient of the ester formulation can provide good to excellent control when applied at 1 to 1.25 ounces of product per gallon of water (0.75% to 1.5% of the total solution). One such product with this concentration is Brushtox Brush Killer with Triclopyr. Other ester formulations with less concentrate are also available including Crossbow. Mixing triclopyr ester with commercially available seed oils can offer better penetration. One available product is Southern Ag Methylated Seed Oil. Mix this at 1.25 ounces of product per gallon of herbicide solution (1% of the total solution). Triclopyr is also available in the amine formulation. Products available include Bayer Bio Advanced Brush Killer Plus, Ortho Brush-B-Gon Poison Ivy and Poison Oak & Brush Killer, and Monterey Brush & Vine Control.
The drizzle application method is good in situations of dense planting, or when it is difficult to cover an entire area due to topography. Glyphosate formulated into a product with 41% active ingredient can provide good to excellent control of pokeweed when applied at 13 ounces of product per gallon of water (10% of the total solution).
You also can apply triclopyr ester using a drizzle application. Products containing 61% active ingredient should be applied using 6.5 ounces of product (5% of the total solution) and 25 ounces of seed oil (20% of the total solution) per gallon of water.
Remember that although the drizzle technique uses a higher concentration of herbicide, you are applying it at a lower volume. One gallon of mixed herbicide solution should adequately treat one-half acre of densely populated pokeweed.
The best time to apply either herbicide is during active plant growth. Seedlings can be treated in early spring through summer. Mature plants should be treated in late summer during flowering as this will draw the herbicide into the root system. Glyphosate is a non-selective herbicide that has no soil activity and triclopyr is a broadleaf selective herbicide with very limited soil activity. When air temperatures are higher than 80°F, it is better to use glyphosate or the amine formulation of triclopyr, since the ester form is subject to vaporization.
All photos from J.M. DiTomaso and E.A. Healy, Weeds of California and Other Western States, 2007.
No endorsement of named products is intended, nor is criticism implied of similar products that are not mentioned.
This profile of pokeweed is another in a series on invasive plants from the City Green blog by the Portland Bureau of Environmental Services.
Photo from Portland City Green blog by the Bureau of Environmental Services.
Pokeweed might look decorative with large, smooth leaves, dark purple berries and green, red or purple stems, but it is an invasive plant.
Pokeweed is native to the southeastern United States, but is increasingly popping up around the Pacific Northwest. It was likely brought here for landscaping interest. It starts off small but can quickly grow into a large bush.
The Portland Bureau of Environmental Services, the East Multnomah Soil and Water Conservation District and other agencies ask for help getting this weed under control before it spreads even more.
Why is pokeweed bad? Birds often eat the berries and carry the seeds to new locations, including natural areas. Left unmanaged, pokeweed can form dense patches and overwhelm native plants and trees. This damages the region’s natural areas and parks, which we depend on for clean water, wildlife habitat, recreation and other benefits.
Here’s another reason: Although birds seem to be immune to the berries, every part of the pokeweed plant is toxic to people. Some people eat parts of the plant (poke salad is an example). But preparation is tricky and ingesting improperly prepared pokeweed can cause severe nausea, or even death.
Environmental Services staff are surveying some neighborhoods for pokeweed to help property owners identify it and give them recommendations for dealing with the plant.
If you see it, remove it carefully. Put berries and flowers in a bag and in the trash, not in your yard debris bin or compost. Stems without berries or flowers can be put in yard debris.
Pokeweed is a perennial plant, which means the stems, leaves and flowers die each year, but the roots — and therefore the plant — stay alive through the winter. In spring, each plant will send up new stems and leaves.
Digging up the whole large tuberous root systems and disposing of them in the trash is the best way to remove the plant. The roots will likely need to be watched for a couple of years, in case pieces re-sprout.
This plant has sometimes been mistaken for Japanese knotweed, another invasive species in northwestern Oregon, due to its hollow red stems and large ovate to lanceolate leaves.
Alternatives: Choose one of many noninvasive garden greens like kale or spinach,
Read about Portland’s Invasive Species efforts and to get involved, join a group like Friends of Trees and Portland Parks and Recreation.
— Homes & Gardens of the Northwest
If you want to receive more tips, sign up for the free OregonLive.com’s newsletter.
Pokeweed, Phytolacca americana
Reproducing only by seed.
Stems (Fig 8) produced from taproot, erect, usually 1-2m high but up to 3m high, smooth and hairless, pinkish to bright red, dying down to the ground each year.
Leaves (Fig 4,5) alternate (1 per node), the lower quite large, up to 30-50cm long and about 1/3 as wide, upper leaves shorter and smaller and with shorter leafstalks; all leaves usually dark green above, lighter green to pinkish-green below and with prominent pinkish veins.
Flowers and Fruit
Flowers (Fig 6) greenish-white to pinkish in slender racemes at the ends of the main stem and branches. There are no petals, 5 petal-like sepals (a), 5 to 30 stamens but usually only 10, and a ring of 10 pistils in the centre; at maturity these form a flat, ring- ring-shaped, juicy, purplish berry with 4 to 10 (usually about 6) sections (b), each with 1 large hard seed. The whole plant, but especially the ripe berries, has an intense purplish-red juice that was used for dyeing. Flowers from June to October.
Roots and Underground Structures
Thick perennial taproot, as much as 10-15cm in diameter, very poisonous.
Pokeweed is a native plant which occurs in meadows, edges of woods and waste areas in the southwestern part of southern Ontario; elsewhere in the province it may persist in old gardens after having been cultivated for the young leafy sprouts which are used as a green vegetable if properly cooked and re-cooked, with the cooking water discarded 3 times.
The soft, smooth, fleshy texture of leaves and young stems (Fig 2,3) and the absence of an ocrea at the base of each leaf distinguish Pokeweed from Lamb’s-quarters, Pigweeds and the Docks, respectively, with which it might be confused. The flat, juicy, 4 -10-seeded purplish berries arranged in a spike at the ends of smooth stems and branches distinguish it from wild blackberries and raspberries.
Pokeweed can be toxic to humans and livestock. Toxins are concentrated in the berries, seeds and roots. The plant is poisonous to livestock.
Research is being conducted investigating a protein isolated from the pokeweed plant, pokeweed antiviral protein (PAP), which may be a promising nonspermicidal broad-spectrum antiviral microbicid. D’Cruz, OJ., Waurzyniak, B., Uckun, F. (2004) Mucosal toxicity studies of a gel formulation of native pokeweed antiviral protein. Toxicologic pathology. 32:212-221.
Pokeweed leaves can be edible, although this is often advised against. There have been reports of people consuming the leaves after first boiling them three times and discarding the water after each boiling. Historically, native peoples have used berries to make a red ink or dye. Armstrong, Wayne. Pokeweed: An Interesting American Vegetable. Retrieved on 2008-06-23.
Close up of pokeweed berries.
Dark purple berries of pokeweed plant.
Purplish stem of pokeweed.
Young pokeweed plants growing in horse paddock, in June, Central Ontario.
Young pokeweed plant.
Young pokeweed plant.
New leaf of pokeweed plant.
Small white flower.
Pokeweed plant in June, Central Ontario.