With its innocent looking, poison oak is an annoying plant that when touched can cause an itchy rash. The rash can then progress into blisters or worse, skin poisoning. It can thrive in a variety of environments, so don’t be surprised to find it near your home or workplace. To avoid contact with the plant, it is important to learn how to kill the poison oak.
How to Kill Poison Oak
1. Kill It Manually
If you decide to kill poison oak by removing it manually, it is important to note you must remove all of it, including the roots. It is a hardy plant so any roots left behind can allow for regrowth. You can either pull the plant out by hand or dig it out with a pick or shovel. The ideal seasons to remove poison oak is early in the spring or fall when it is easier to remove because of the moist earth. If the ground is hard, you have a greater chance of leaving some of the plant behind.
Beware! Just pulling out the plant doesn’t mean the debris can’t still affect you. Even if dried out, poison oak rubbish can still have contaminant on it, until you can bury it, take it to an approved dump for yard waste, or stack it in an area that is out of the way. Whatever you do, don’t burn it. It doesn’t do anything but create a fire hazard.
When pulling out poison oak, make sure you wear protective clothing. It is best to wear a long sleeve shirt, long pants, boots or long socks under shoes, gloves and if possible, a face mask and protective eye wear. Wash everything after you are done, including your footwear. If you happen to come in contact with any of the poison oak, make sure to wash the area thoroughly to reduce your risk of developing a rash.
2. Apply a Chemical Treatment to Poison Oak Stumps
If you don’t want to pull out a live plant, you can kill it first with a chemical treatment. Common chemicals used for this purpose are triclopyr, glyphosate or a combination of the two. You will want to apply the poison in the spring when the plant is green so it will absorb it more readily. Once it has died, you will need to dig the plant out. To try this technique, do the following:
- Make sure to wear protective clothing, gloves and shoes, just like you would if you were pulling out a live plant.
- Use a lopper with a long handle to cut the plant until only stumps of the stems are left, no more than 2 inches.
- Then spray or brush the chemicals onto the stumps. Make sure you cover it well, remembering to check for new growth that will have to be treated as well.
- Within a few days, the stems should turn brown. Dig out the dead roots and properly dispose them. Do not burn or mulch it, as contact even with the dead plant can cause an allergic reaction or rash.
3. Use an Early-Season Spray
Early-season herbicide spray is made of the chemical triclopyr. When thinking how to kill poison oak effectively, consider this method. It works best if you apply it during early spring, but no later than mid-summer. Tips to consider:
- Only spray when the weather is calm. If it is too windy, the herbicide can accidently spray on neighboring plants and kill them as well. Also, you run the risk of having the wind blow the spray backwards into your eyes and face.
- Remember, the spray is damaging to trees. If the poison oak is located close to a tree, take care to only apply it to the plant’s stems, not the tree’s trunk, branches or leaves.
- Most plant herbicides require 24 hours to work at its best. If it is raining or there is a forecast for rain of the next day, do not spray.
4. Use a Late-Season Spray
If you discover a poison oak at the end of the summer or in the fall, a good alternative is to use a late-season herbicide. This type of poison contains glyphosate. The solution is made up of a 2 percent glyphosate solution and is applied directly to the leaves.
- As with the early-season spray, do not apply when windy outside as it can kill nearby plants. It can also damage your eyes or skin if the wind causes it to blow back at you.
- Trees can be damaged by late-season herbicide, so do not spray on or near them. If your poison oak is nearby, take care to only spray the plant.
- Do not spray when you are expecting rain or if it is raining. The herbicide needs to be on the poison oak for at least 24 hours to work.
5. Cover the Plants
Another way to kill poison oak is by covering it. Cut the plant as far down as you can, only leaving a few inches of it above the ground. Also, consider that the method only works for poison oak in a confined area. Cover the plant in plastic sheeting. When the plant dies, remove the dead roots and throw them properly away. If you leave the roots, you run the chance of the poison oak growing back.
6. Use Boiling Water
If the plants you want to get rid of are small, you may consider using boiling water to kill them. Simply heat water to a boil and then pour it on or near the poison oak’s roots. Of course, this should only be used on plants located outside. Once the plant dies, you must dig up the roots and dispose it. This method will not work on large plants. Take caution and do not breathe in the steam coming from the boiling water being poured on the plants.
7. Use Goat to Do the Job
A natural way to kill poison oak is to hire goats to eat the plants. Goats are immune to its negative effects. The ravenous creatures can quickly get rid of the pesky plants and are a great option to consider when thinking about how to kill poison oak.
Just like the other methods, you must get rid of the roots to prevent the plant from growing back. If you do not want to dig them out, you can hire goats early every season to clear out any new growth. Several goat farms lease their animal for landscaping purposes and there are no ill effects on the animals, not even the milk of nursing mothers.
8. Try a Vinegar Spray
Some people use vinegar spray as a method of killing poison oak. If you want to try it, remember it will only work on small plants.
Fill a spray bottle with white vinegar. Do not dilute it with any water; just plain vinegar will do. Spray directly on the plant’s leaves and stems. If it works, the plant will die within a couple of days. Dig out the roots to prevent regrowth.
9. Consider Getting a Professional Involved
If you are confused about all the ways on how to kill poison oak, you might want to call a professional. If you have a high sensitivity to the plant or just don’t want to deal with it yourself, hire a licensed professional.
A professional can administer a stronger pesticide like Imazapyr. This herbicide will completely eliminate the poison oak. The best time of the year to hire an expert is in the spring or early in the fall.
10. Plant Your Yard with Healthy Groundcover
Finally, you might want to consider planting healthy groundcover over your yard to prevent poison oak from making its way into your property. Poison oaks prefer bare ground and open space, so if you fill that space, they will be deterred from the spot.