Tree-of-heaven (Ailanthus altissima), native to China, grows quickly and can ultimately reach up to 80-100’ in height. Tree-of-heaven was first introduced into the U.S., in the Philadelphia area, in 1784. It is particularly invasive in urban landscapes and establishes quickly. The plant is resistant to pollution and can tolerate very poor soils. Tree-of-heaven is very common in the Midwest, lower northeast, as well as the west and southwest coast. Well-established tree-of-heaven stands are only eliminated through repeated monitoring and control efforts. Initial treatments often only reduce the root systems, making follow-up measures necessary.

The Autumn olive (Elaeagnus umbellata) is an invasive, deciduous shrub or small tree. This densely branched plant can grow up to 20 feet and up to 30 of leaves. The Autumn olive is a fast grower and prolific seed producer. While roots are capable of fixing nitrogen in the soil, Autumn olive out-competes and displaces native shrubs. Autumn olive, native to China, Japan, and Korea, is found in the U.S. from Maine, south to northern Florida, west to Nebraska, with scattered infestations in the Northwest U.S. It was introduced into the U.S. in the 1830s, for erosion control and as a windbreak, and for its showy foliage, flowers and berries.

Phragmites australis is an aggressive, robust perennial grass, which creates dense infestations. It is easily identified by its height (five to thirteen feet) and feathery flowers, which appear in June. Phragmites creates dense monocultures in freshwater marshes and wetlands, as well as along river edges and roadsides. It is common to brackish (slightly saline) environments and disturbed sites. Its salt tolerance allows it to persist where few other species can survive.