Autumn Olive is an inoffensive looking shrub or small tree with silvery green leaves, yellow flowers, and red berries in the fall. Unlike many of the invasive plants that plague Granby lands, it is not yet universally established and controlling it is more feasible.
By May, Autumn Olive’s leaves are fully developed, and its fragrant yellow flowers are in full bloom, making it easy to identify and remove.
It grows rapidly in a wide range of soils and is often found in “disturbed” habitats and at the edges of fields and near streams. Its ability to grow quickly in infertile areas allows it to colonize areas quickly and crowd out slower-growing varieties.
Russian Olive (Elaeagnus Angustifolia) looks similar and is considered potentially invasive. Its leaves are silvery on both sides, not just the back, and it has yellow berries, not red.
Why it’s a problem
People brought Autumn Olive from Asia in the 1800s as an ornamental shrub, and it was widely planted, including along Connecticut highways for erosion control. It escaped cultivation and now runs rampant across much of the eastern U.S.
Autumn Olive is equipped with an unusual tool: it creates its own food. Autumn Olive extracts nitrogen, an essential plant nutrient, from the air and makes it available in the soil for nourishment just as the plants farmers use to enrich their fields (clover, peas, other legumes). This allows it to flourish and become dominant in poor soil where other plants and trees struggle and grow slowly. Autumn Olive grows rapidly, and mature shrubs produce thousands of seeds that are gobbled up and widely distributed by birds and animals.
What to do
Remove it. The most effective way to control Autumn Olive is to identify and completely pull out young plants. It’s important to pull up all the roots because the plant can restart from root fragments. Springtime is the best time to pull young plants, when the soil is moist. With mature shrubs, it’s much harder to extract all the roots, and just cutting the shrub encourages growth. An effective alternative is a careful cut-and-paint strategy in late summer using a liquid herbicide.
Gaining control over apparently invincible invasive plants may seem as difficult as reversing a worldwide pandemic. But the lessons are the same: trust science-grounded facts, vigorously apply tested strategies, and work together to multiply our efforts. In the long run we will prevail, and be better for the struggle, together.
For more information on invasive plants, events and the NOT WANTED campaign, drop us a note on the Granby Conservation Commission webpage.