28 Poison ivy

first_imgPoison ivy (Rhus radicans) is found mostly in moist,deciduous forests and wooded areas. Unfortunately, it’s alsofound on trees, fences and ornamental plantings in Georgialandscapes.A related species, poison oak (Rhus toxicodendron), mayactually be a type of poison ivy.Poison ivy may grow as a small shrub or a high-climbing vine ontrees, fences and buildings. Each compound leaf has three brightgreen, shiny leaflets.Remember the ruleThe shape of the leaves and presence of hairs on the undersidesvary greatly, so people may not always recognize poison ivy. Theold saying, “leaflets three, let it be,” is a good rule.Poison ivy has small flowers with five yellowish-green petalsarranged on slender stalks. Its small, grayish white berries arefood for more than 55 bird species.Box elder (Acer negundo) is often confused with poisonivy. Its seedlings have three leaflets, too, but they haveopposite leaves. Poison ivy leaves are alternately arranged onthe stem. Virginia creeper (Parthenocissus quinquefolia)can look like poison ivy, too. But its leaves usually have fiveleaflets.The Rhus cousins are said to cause more contact dermatitis(redness, rash, blisters and itching) in the United States thanall other plants and industrial or household chemicals.All poisonAll parts of poison ivy are poisonous year-round. A toxic, oilycompound (urushiol) is quickly exuded if plant tissues are brokenin any way. People are exposed as they brush against the plant ortouch equipment, clothes or pets that have touched it. It caneven be carried in the smoke from burning the vines.Only the oily toxin, though, can spread the rash. Symptomsusually appear in 12 to 48 hours but may not show up for days.If you think you’ve contacted poison ivy, washing your skin withcold water within 5 minutes may keep the urushiol from contactingyour skin. Within the first 30 minutes, use soap and water.Consult a physician or pharmacist for the best treatment.Continually clipping poison ivy at or near the ground willeventually control it. But you may have to clip it several timesduring the year for several years.Can you dig it?Digging poison ivy plants and roots can control it in small bedsof landscape ornamentals. Be sure to wear watertight gloves,though.Herbicides can control poison ivy, too. But always read all labeldirections. Poison ivy has extensive roots, so you’ll likely haveto apply herbicides many times.Glyphosate is the active ingredient in Roundup and many otherproducts. Apply it directly to the foliage of poison ivy. Itworks well on warm, sunny days when plants are actively growing.It’s best when plants are flowering or fruiting, generally inearly summer in Georgia.You’ll need at least one rain-free hour after applying glyphosateto get the best results. The product can severely injuredesirable plants, so don’t spray it on windy days. Use coarsesprays with large droplets to minimize drift.Cut and sprayWhere poison ivy has grown into large trees, cut the vine 2 to 3feet above the soil. Within 24 hours, spray the leaves of thelower section (if any) with a 5-percent to 10-percent glyphosatesolution (using at least a 41-percent glyphosate concentrate tomake the spray solution).If there are no leaves, paint or spray the lower stem portionwith 50-50 glyphosate-water solution or undiluted glyphosate(with at least a 41-percent glyphosate concentrate.Triclopyr (Brush-B-Gon) is recommended around homes, fences andnongarden areas.It’s often used to keep poison ivy and other plants from comingback after being cut. Just clip the poison ivy vine near the soilsurface. Then paint the freshly cut surface with undilutedtriclopyr. Don’t apply it, however, to the bark of any trees.Repeat the treatment when regrowth appears.(Mark Czarnota is a Cooperative Extension horticulturist andTim Murphy an Cooperative Extension weed scientist with theUniversity of Georgia College of Agricultural and EnvironmentalSciences.) Volume XXXINumber 1Page 38 By Mark Czarnotaand TimMurphyUniversity of GeorgiaEveryone who works outdoors with plants or goes hiking, camping,picnicking or other outdoor activities should be able to identifypoison ivy. Failing to know it when you see it can lead to severeallergic reactions.last_img read more

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