Chemical herbicide against poison ivy, poison oak and poison sumac
The use of herbicide can help to control poison ivy and avoid the dangerous uprooting by hand. A glyphosate herbicide should be applied on foliage after the period of active growth of the plant in July and August, when the foliage is fully deployed and the plant is in the phase of energy capture through its leaves.
Auxinic herbicides such as triclopyr (the most effective), 2,4-D, dicamba, and combinations of these herbicides can be applied earlier than glyphosate, from spring to midsummer. The flowering stage is also a good time to spray auxinic herbicides. A single treatment, which poisons the plant to the root and kills, may suffice, but may be not enough for tough poison oak plants. If there is regrowth, especially on older and vigorous plants, it may be necessary to repeat the treatment. You must spray the herbicide directly on the plant and avoid damaging surrounding plants you want to keep. Be careful! Chemicals pollute the soil and will not dissolve in nature like salt and vinegar.
Many types of chemical
Chemical herbicides for domestic use available in garden centers or hardware stores, typically contain one or a mixture of the following active ingredients:
- Glyphosate: Roundup for poison ivy (1% glyphosate)
Ortho Brush-B-Gon Poison Ivy and Brush Killer (0,8% triclopyr),
Bayer Advanced Brush Killer Plus (0,8% triclopyr)
- Amitrole, amitrole T: Nufarm
- 2,4-D, chlorophenoxy
- Combination of 2,4-D and dicamba:
Spectracide Poison Ivy & Poison Oak Brush Killer,
Bonide Poison Oak & Ivy Killer.
- Combination of glyphosate and imazapyr:
Ortho Groundclear Vegetation Killer (1% glyphosate)
- Simazine (banned in Europe since 2003)
- Ammonium sulfamate (banned in Europe since 2007)
The effects of the herbicides may be influenced by the combination of the active ingredients. For example, when dicamba and 2,4-D are combined, it provides much better control. These herbicides are available in premixed combinations. Applied on poison oak, dicamba used at 0.5% gives a better long-term control than 2,4-D. Furthermore, triclopyr ester plus 2,4-D ester is more effective and gives better absorption into the leaves. Complete operating instructions for each herbicide are indicated on the product label.
On toxicodendron shrubs
It is possible to apply herbicide on the stump of the toxicodendron shrubs or thick vines. Stump treatments are most effective during periods of active growth in spring and summer. Cut the shrub or thick vine 2 inches (5 cm) above the soil surface, and treat the stump immediately with herbicide. Use herbicide like glyphosate, triclopyr, or combinations of triclopyr with 2,4-D (or 2,4-D and 2,4-DP). Apply it with a 1 to 2 inch paint brush or with a plastic squeeze bottle. Treatment solutions should contain either undiluted glyphosate (use a product that contains at least 20% glyphosate), triclopyr amine, or a 20 to 30% triclopyr ester solution mixed with 70 to 80% methylated or ethylated seed oil.
It is also possible to apply herbicide on the base of the trunk. Apply triclopyr to cover a 6 to 12 inch (15 to 30 cm) at the base of the trunk. Other types of herbicide are less adequate for that job. Chemical herbicides work very well against poison sumac.
The cost of chemical herbicide
Unlike the free uprooting, the use of chemical herbicides costs a lot. And a gallon (3.5 liters) may be necessary to cover only 200 square feet of ground densely covered with poison ivy. Over a large area, this technique can be expensive, so table salt and/or vinegar can save you money.
Roundup Herbicide (1% glyphosate)
Ortho Groundclear Herbicide (1% glyphosate)
Ortho Herbicide (0.8% triclopyr)
Bayer Herbicide (0.8% triclopyr)
Spectracide Brush Killer Herbicide
Bonide Poison Oak & Ivy Killer (0.6% 2,4-D)
Finale Herbicide (11.33% glufosinate ammonium)
Videos about chemical herbicide
Resources about chemical herbicides
Organic defoliant herbicide: St.Gabriel
Made from plant oils
St. Gabriel Laboratories Poison Ivy Defoliant kills the leaves of poison ivy, poison oak and ivy type plants by burning through the cell structure. The Poison Ivy Defoliant contains clove oil to induce a rapid burn down of plant tissue on contact. It will not kill the plant like the chemical herbicide will do but the plant will be hardly weaken and will die slowly.
How to use this herbicide
Apply a liberal amount to both sides of leaves and vines until run-off.
For complete removal of ivy type plants including poison oak, physical removal of the burned down plant is required. Use gloves and pull dead vines from the Earth making sure to take up as much of the root system as possible.
This product can be used around the home, buildings, including schools, in fence rows, along tree lines, garden and flower beds, and right of ways. It is safe to use around pets and children and sensitive environmental areas including ponds and streams.
Make sure not to over spray on off-target plants as damage will occur, resulting in unwanted plant damage.
- Clove Oil 12%
- Sodium Laurel Sulphate 8%
- Citric Acid
- Mineral Oil
Salt, vinegar and bleach homemade defoliant herbicides
- Not as risky to humans as chemical herbicides can be.
- Doesn’t kill the plant the first time.
- Salt and chlorine will pollute the soil after many applications.
Salt homemade herbicide
The use of table salt, or sodium chloride as a herbicide is a homemade and affordable version of Adios Ambros by Herbanatur used to eliminate ragweed. Table salt (and vinegar) is effective on western and eastern poison ivy , but less so on high poison oak or poison sumac. Sodium chloride in a solution of water sprayed on the leaves, fruits and stems, will wither the plant. Sodium chloride attacks and burns the surface of leaves and tender parts of the plant in a few days. To dry the plant out completely, it may be necessary to reapply the salt solution 3 days after the first application. Unlike chemical herbicides, salt will be washed from the plant and ineffective if it rains heavily within 3 days after application.
Sodium chloride leaches into the soil and does not pollute as can do chemical herbicides. In general, the plants are completely dried after one week. If regrowth occurs on very vigorous plants, another application of salt solution will be required. On my property, after 2 weeks the salt solution was as effective as the herbicide Roundup from Monsanto on one densely populated area of poison ivy.
Unlike chemical herbicides that poison the plant to the roots and kill the plant, sodium chloride attacks the aerial parts of the plant and prevents it from capturing energy during its period of dormancy to survive the winter. As poison ivy captures energy through its roots and leaves, killing the leaves limits its ability to survive and spread. Regrowth may happen the following spring, but the area colonized by poison ivy will be greatly diminished. Another application of salt solution or a simple uproot will be necessary to complete the work.
My salt herbicide recipe
The composition of this salt solution is simple:
AT LEAST 120GR OF SALT (SODIUM CHLORIDE) IN 1 LITER OF WATER.
I often also add bleach (see below).
The cost of salt herbicide
With a box of 1 kg of salt you can produce more than 8 liters of solution at an unbeatable price, although a single application is often not sufficient. Personally, I found in a “dollar store” 2 boxes of salt 737 gr for $1.
It costs $0.68 per kilogram of salt…
so $0.30 per galon or $0.08 per liter of herbicide.
Vinegar homemade herbicide
In addition to table salt (sodium chloride), it is possible to use vinegar (acetic acid) as a homemade herbicide. The classic and most affordable white vinegar (5% acetic acid) will do the job. As with salt, vinegar withers leaves and tender parts of the plant and greatly weakens it. Drying of the plant is visible in a few hours to a day after application. It is most effective to spray vinegar directly on the plant, without diluting it. It is also possible to prepare a solution of salt and water, as seen above, and add vinegar to increase the wilting. Several recipes are possible; just experiment to find the best dosage for your situation.
The cost of vinegar herbicide
If you use the cheapest white vinegar directly on the leaves (5% acetic acid), without diluting it in water, expect to pay around…
3.50$ per gallon or $0.90 per liter.
So 10 times the cost of the salt homemade herbicide.
Bleach is also an excellent herbicide and defoliant. Like salt and vinegar, it dries the leaves of the poison ivy. It is important to apply it only on the leaves of poison ivy because the herbicide will kill all the plants on which it is sprayed. A good recipe is to mix 250ml (1 cup) of bleach to 1 liter of water. We can add salt, as seen above, to accentuate the dryness of the plant. In addition, bleach has an oily texture which sticks to the foliage of the plant and improve the effect of the herbicide. You can accentuate this “catchy” property by adding dish soap, as seen below.
The cost of bleach herbicide
The advantage of bleach, like salt, is the price.
A bottle of almost 2 liters will cost $1.25.
With my proposed recipe, it will cost about $0.18 for 1.25 liters of herbicide.
In comparison, with table salt it comes to $0.08 per liter of herbicide.
Several mixes are possible.
Add dish soap
The problem of water-based herbicides is the flowing of the liquid along the leaves and dripping on the soil. If the solution is foamed, or thickened, it will cling more easily to the plant. To make the salt or vinegar solution more effective, simply add dish soap to the solution. Again, many recipes are possible and just try dosing.
Use a good sprayer!
Quality garden sprayer is an essential tool for any gardener who uses chemical herbicides and basic salt or vinegar. There are herbicide sprayers as backpack that can carry large volumes of liquid (5 liters or more). Some smaller handheld sprayers have a volume of 1 to 2 liters. Often a handheld sprayer is sufficient to treat a small area affected by poison ivy. Be carefull, sometimes salt grains clog the spray nozzle. So, it is important that the sprayer has a filter within the reservoir so that the salt grains can not enter the pipe and clog the spray nozzle.
Two periods of spraying herbicide on poison ivy
1- On young shoots (from May to July)
My favourite technique: “open the fire!” Apply salt herbicide on all poison ivy plants as they appear in late May. The tiny shoots have thin and soft leaves and are easily destroyed by the herbicide. Once the shoots are withered, the mother plant will launch new shoots a few days later. Again, destroy them with salt herbicide. Whenever the plant develops new growth and new leaves, it is weakening. The poison ivy leaves need to create and store energy to survive and grow. The plant is in active growth period until the beginning of July. Then, fewer leaves will come out and the plant will weaken.
2- On mature leaves (July-August)
Wait for July, when leaves and fruits are fully mature to apply the salt herbicide on all leaves and fruits. Once the plants have withered and dried, no new shoots arise because the active growth period has passed. The problem with this technique is that the mother plant has time to store energy during May and June and will be more difficult to eradicate. Moreover, its fruits may have been spread by birds.
When spraying herbicide?
Since it is not a chemical herbicide, home-made herbicide with salt, vinegar or bleach fears rain. Avoid wasting time by spraying the herbicide during the 2 days preceding a rain event. Here’s how to interpret weather forecasts.
Videos about homemade herbicides
Resources about homemade herbicides
How to cut poison ivy?
Mechanical Alternative to Defoliant Herbicide: Shears
- Doesn’t pollute the soil.
- Weaken immediately the plant of poison ivy.
- More likely to come in contact with poison ivy.
- The shears in contact with the plant could later create a rash.
If you do not want to risk polluting the soil in any way, you should avoid using salt, vinegar and bleach (dish soap does not harm nature, or almost). You could use a long edge shears for lawn to cut the aerial parts of the poison ivy plant.
Like with the salt-vinegar-bleach defoliant herbicide, the poison ivy plant will be weakened by these cuts. Some regrowths will appear and will have to be cut as well. The next year, you will see shoots but 80% of the plant will be dead. Again, you will have to cut them.
Be careful! The shears will touch and cut poison ivy! It will be full of oil and urushiol. To avoid a serious skin rash due to poison ivy, you must protect yourself and store the tool with a plastic bag on the shears.
Some Good Long Handle Edge Shears
How to Remove Poison ivy?
Identification and protection
Before declaring war, we must identify the poisonous plants and delineate areas to be treated. Some places may be colonized in part, meaning poison ivy shares an area with other native plants. Other places can be completely covered with poison ivy.
Once such areas have been identified, dress appropriately. Wear thick or waterproof trousers and rubber boots slipped into plastic bags. The plastic bags will be in direct contact with the plants and can be discarded after use. If the goal is to extract plants, wear gloves and an old shirt with long sleeves that can be discarded after use. Ensure that no part of your skin comes into contact with the plant or its sap. Do not touch your face with contaminated gloves.
Poison ivy reproduces with difficulty from fragments of roots or stems, so the best way to prevent reproduction is to remove it. Digging and removing the roots and stems by hand minimizes the ability of the plant to reproduce stems. Uprooting is easier after a good rain when the ground is wet and soft. In addition, you should avoid sudden gestures to avoid accidentally getting plants in contact with your face.
Let’s remove poison ivy!
Complete removal is the most effective and affordable way to fight poison ivy and poison oak, although risky for the person who is responsible for this task. To remove easily the western poison ivy, you need a damp wet soil, so wait the day after a big rainy day. Remember that the roots of the western poison ivy are creeping just under the soil surface. It is also important to pick up any dead plant with its seed. In the fall, once the surrounding vegetation has disappeared, these clusters of seeds are clearly visible.
It is also possible to smother new shoots in the spring by covering with mulch or ideally thick black plastic. You can leave the mulch in place a full season and even longer.
Eliminate poison ivy
Any poison ivy plant (or other poisonous toxicodendron), even dead, can still cause dermatitis, and should be handled with care. The easiest way to dispose of the plants is to fill garbage bags and throw them out like household waste. You can also bury the dead plants at least one foot (30 cm) deep into the ground to avoid any possibility of regrowth. Do not burn poison ivy plants, because the urushiol could volatilize and be transported in the smoke and cause very serious reactions to a sensitive person.
Videos about removing poison ivy
Fungus herbicide (soon)
American researchers have identified a fungus naturally capable of eradicating poison ivy.
The fungus Colletotrichum fioriniae attacks poison ivy, causing a disease that results to the death of the plant. Jelesko John and Matt Kasson, of Virginia Tech University, believe it would be relatively easy to develop granules of fungus that we could sprinkle on infested areas with poison ivy. The two scientists believe the fungus would be more effective than chemical herbicides, in addition of the advantage of being natural and harmless for humans. That new product is not available on the market for now. We look forward.
Resources about Colletotrichum fioriniae
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- Marie Stoves on September 19, 2018. I have a poison ivy plant climbing a corner of my stone wall. Will the salt and vinegar mixture totally kill the plant? I expect it will take a few applications. But if I kill it back now with this mixture can you give me any idea how long it might take to kill the root itself?
- Hi Marie. Thanks for your comment. Salt vinegar is a defoliant that weakens the plant and does kill it only after many applications on over 2 years, maybe. To kill the plant rapidly, use RoundUp. Good luck.
- Dara on November 6, 2018. What about spraying the plants between September and may? I just bought a house. The yard is full if poison ivy and sumac. The leaves are off the sumac and all over the yard. It’s going to snow soon. My dog keeps exposing me to it. I’ve found I’m very allergic. I’m trying to figure out what to do. I bought a hazmat suit and was planning on pulling it out this week but I’m afraid of it and how to keep it from coming back in the spring. Thank you in advance for your help.
- Hi Dara. Thanks for your comment.
It’s unuseful to spray the poison ivy when leaves are down. Herbicide can’t work if sprayed on the stem (branch). So, from fall to spring, what you can do is to cut the stem or pull out the plant carefully. When the snow will come that snow will protect your dog (and you) from the falled leaves and stem. In the next spring-summer the new leaves will grow and you will be able to spray them with RoundUp. It will be radical.
I wish you good luck.
- Hi Dara. Thanks for your comment.