Plan the perfect garden with our interactive tool →

Garden Weeds Which Cause Rashes

Although gardens are home to beautiful and attractive flowers and vegetables, they are often home to weeds as well. These invasive plants are not only unsightly, but some varieties cause rashes. Know some of the more common garden weeds that cause rashes is the best way to avoid trouble.

Cotton Bush

The cotton bush (Gomphocarpus fruticosus) is an evergreen shrub exhibiting narrow leaves and white, tube-shaped flowers. The balloonlike fruits are covered with green spines, and the seed has a tuft of hairs. All parts of this weed are poisonous, and the seedlings are often more toxic than the mature version of the plant. When weeding, avoid the sap, which can cause skin rashes. The other parts of the plant can cause stomach upset.

Pellitory/Asthma Weed

The pellitory, also known as the asthma weed (Parietaria judaica), is a perennial identified by the fine hairs growing on its stems and leaves. The stems appear reddish and the leaves are green and lance-shaped. It has small, greenish flowers. The pollen causes allergic reactions, and the hairs can stick to clothing, which often leads to skin irritation, sometimes be quite severe. The plant also causes asthma, conjunctivitis and hay fever.

Stinging Nettle

Most gardeners are familiar with this garden weed, which has a well-deserved reputation for its ability to cause painful and itchy skin rashes. There are several related varieties of nettle, including the giant, scrub and dwarf. It appears as a perennial herb, with oval or lance-shaped leaves with toothed margins. It also possesses hair-covered leaves and tiny clusters of flowers. The pollen causes hay fever, while the hairs cling to the skin and cause a painful irritation and rashes.

Giant Hogweed

The giant hogweed (Heracleum mantegazzianum) is one of the most potent garden weeds you are likely to encounter and is listed by the federal government as a noxious weed. The sap, when combined with moisture and sunlight, causes severe skin irritation, as well as blistering, scarring and even blindness. It grows in a number of states from New York to Pennsylvania and as far west as the Pacific Coast, especially Washington and Oregon. It usually appears as a very tall plant, 12 feet or more, with leaves that can grow to 5 feet wide. If you believe you may have touched this plant, consult your physician immediately.

Garden Guides