Last week, I worked in a very overgrown bed in the yard. I knew that it had poison oak in it, but I watched carefully. Obviously, I did not watch carefully enough.

By Sunday, I had the itching rash associated with poison oak and poison ivy.

Many of you also fall prey each year to the discomfort, itching and pain from contact with poison ivy and poison oak. Therefore, this might be a good time to talk about them.

Poison oak and poison ivy both have stems with three leaflets. There is an old saying, “Leaflets three, let it be.” This is a good maxim to follow. Poison ivy is a perennial, high climbing, woody vine. It is often found climbing high on trees, walls or fences or trailing on the ground. The vine has hairy-looking aerial roots and can grow to more than 10 feet tall.

Poison oak is a low shrub growing 1 to 6 feet tall.

They are both very similar in appearance, the difference being that poison oak does not climb.

All part of the plants are poisonous. The toxic principle is a phenolic compound called urushiol. It is a skin and mucous membrane irritant.

Some people, like me, are very sensitive to the effects of the toxin. If I come in contact with the plant, it means a trip to the doctor. Other people, like my husband, show no ill effects from coming into contact with the plant.

The toxin has little or no effect on animals, but pets carry the irritating substance on their hair and thereby transmit it to humans.

The oil which causes the irritation can even be transmitted through the smoke from burning poison oak and poison ivy, so burning is not recommended.

Remember that the root also has the toxin in it. I was pulling up honeysuckle roots, and I think that is where I came into contact with the poison oak.

Become familiar with how these plants look and avoid them. If you come into contact with one of them, immediately wash your skin with strong soap and hot water and remove and wash all clothes, including shoes and socks, in hot soapy water.

Keep your hands away from your face and mouth. If you develop a rash, don’t scratch it. You can apply calamine lotion, zinc oxide treatment or a paste made with baking soda and water to the rash. If these measures don’t work, call your doctor.

You also need to clean the tools you were using. The toxin can remain on tools for up to a year.

Some people have severe allergic reactions to these plants and can have swelling in the throat, breathing problems, weakness, dizziness or bluish lips. Some may even fall unconscious. If any of these reactions occur, seek emergency medical care.

May and June are the best times to apply control measure to these plants, but it can be done any time of year.

Always identify the plant before attempting any control measures. Spraying the foliage with glyphosate (sold under the trade names of Roundup or Kleenup) is recommended. Follow all label directions and use these herbicides with care because they will kill any plant with which they come in contact.

I sometimes brush glysophate on when the poison plants are near plants that I want to be sure are not harmed.

To kill poison ivy on trees, cut the vine above the ground and treat plants on the ground with Roundup. This will kill the roots and prevent sprouting.

Remember that the vine left on the tree or fence still has oil in it, so be careful if you pull the vine down. The roots can also run long distances, so be careful when pulling roots.

Hopefully, you will get rid of all these irritating plants. I class poison oak with mosquitoes and black gnats. I’m sure they serve some good purpose; I just can’t discover what it is.