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Poison Ivy: ID and Control

Poison ivy commonly grows as either a vine on trees or as a shrub. When identifying it, remember the phrase : “Leaflets of three, let it be.”

As we push on through spring and temperatures continue to rise many of us have been busy working or playing in the beautiful weather. However there is one plant that you should continuously be on the lookout for while outdoors during this time of the year and that is poison ivy. Poison ivy is well known for the terrible rash it caused by the oil urushiol that it contains. So today I want to give you all a quick outline of how to properly identify so you can avoid it and also how to control poison ivy in the landscape.


Poison ivy is a woody perennial that belongs to the Cashew family and is well known for the terrible rash it produces when one comes into contact with skin. It may grow as a small shrub or as a high climbing vine with aerial rootlets on trees, fence rows and buildings. Poison ivy reproduces by creeping roots and seed. Leafy shoots can arise from the creeping roots several yards away from the parent plant. Poison ivy leaves are alternately arranged on the stem. Each compound leaf consists of three bright green, shiny leaflets. Leaflets are elliptic to egg-shaped and have either smooth, toothed or lobed margins. The upper leaf surface is smooth, or lacks hairs, while hairs are commonly found on the veins of the underside of the leaf. Poison ivy leaf shape and texture is highly variable and leaves with different shapes may be found on the same plant or on plants near each other. People may incorrectly identify poison ivy when observing a poison ivy plant with an unusual leaf shape. However, the old saying, “Leaflets of three, let it be” should always be followed. While this approach may cause unjust suspicion of a harmless plant, sensitivity to poison ivy must be considered.


Spraying poison ivy with herbicides is the safest way to control, however multiple applications may be needed.

When it comes to controlling poison ivy I prefer to use herbicides because it requires no contact with the plant whatsoever.  Because poison ivy has an extensive root system, multiple herbicide applications are usually necessary for effective control. Repeat applications should be made to the foliage at the full-leaf stage of growth. Glyphosate which is the active ingredient in Roundup may be used if controlling it as long as there are no desirable plants nearby. This would be applicable for use in the woods around your home. Products such as Southern Trimec or Three way which contain 2,4-D, dicamba, and MCPP will also provide fair to good control of poison ivy while also being safe around lawns.  Triclopyr which is sold as Brush-B-Gon or Poison Ivy Killer in most retail stores is a highly effective post emergence herbicide used for controlling poison ivy and numerous other woody vines.

Don’t let poison ivy ruin your time outdoors this spring and summer. Be on the lookout for it around your property and control it as soon as possible to ensure it does not spread. Remember when attempting to ID poison ivy “leaflets of three, let it be.”