Joe Pye Weed Pests

Joe Pye Weed is a flowering perennial native to North America. A member of the Eutrochium genus, this tall wildflower adds height and color to a border or garden bed during the summer and fall. Joe Pye Weed is known for being easy to grow and deer resistant, and is also not favored by many pests. Some typical pests will damage this plant, but pest infestation is not usual when growing Joe Pye Weed.

Common Joe Pye Weed Pests

Aphids

Sap-sucking aphids are tiny insects that sustain themselves by eating the sap from plants, like Joe Pye Weed. Damage from aphids appears as discoloration, leaf yellowing, and curl. A large aphid infestation will cause a buildup of honeydew or waste, attracting ants and other pests. An untreated aphid infestation can cause leaf drop and stunted growth.

Treating Aphids on Joe Pye Weed

Treat aphids using insecticidal soap or horticultural oil. Spray the plant, including the underside of the leaves, to kill the insects. Aphids lay their eggs on the plant, so plan to spray the foliage several times to ensure all of the eggs, larvae, and adult aphids are killed. Remove foliage with significant damage so the plant will redirect energy into new growth.

Preventing Aphids on Joe Pye Weed

Keep aphids away from Joe Pye Weed or at least prevent a large infestation by preemptively spraying the plant with insecticidal soap or horticultural oil. Routinely spray any stray aphids with a strong jet of water throughout the growing season. Avoid over-fertilizing your plant and feature companion plantings that deter aphids, like flowering onions, chives, and garlic.

Leaf Beetles

There are thousands of species of leaf beetles, and they all damage plants by eating foliage. These pests often eat through the leaves, creating a random pattern of lace-like holes. A severe leaf beetle infestation can render the leaves useless, stunting Joe Pye Weed growth or possibly even killing the plant if it cannot sustain itself.

Photo by Katja Schulz, Unedited, Flickr, Copyright CC by 2.0

Treating Leaf Beetles on Joe Pye Weed

Quickly treat leaf beetles by manually removing these pests as you see them. Crush the bugs to kill them and prevent further damage. Spray Joe Pye Weed with an insecticidal soap to kill leaf beetles if you see any larvae or eggs on the plant. You can apply fertilizer to encourage new growth, but do not fertilize Joe Pye Weed late in the growing season since this plant is an herbaceous perennial and will go dormant in the winter.

Preventing Leaf Beetles on Joe Pye Weed

Spraying the plant with insecticidal soap can effectively keep leaf beetles away. Reduce the risk of leaf beetles damaging your Joe Pye Weed by removing debris around the plant and cutting back dead growth in the fall after the first frost. Pests like leaf beetles may overwinter in dead growth, so removing dead plant material also decreases the chances of the pests overwintering.