It was introduced in the United States as an ornamental plant. ... This crowds out native plants and disrupts these ecosystems. Research has shown that the presence of the black-legged tick, which transmits Lyme disease, increases in areas with dense barberry. Japanese barberry has small, oval, alternate leaves.

Why is barberry considered invasive?

Ecological Threat

Where it is well established, barberry displaces many native herbaceous and woody plants. In large infestations, its leaf litter causes changes in the chemistry of the soil, making it more basic.

Why are barberry bushes bad?

But the attractive Japanese barberry is an invasive species that can grow unchecked by predators or diseases, taking space and sunlight away from native plants and trees. ... It provides a haven for ticks that carry the bacteria responsible for Lyme disease.