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Invasives Watch

     

     

    Invasive Plants to Watch This Month

    There are several invasive plants that should be on your radar:

    • Autumn Olive (Elaeagnus umbellata)
    • Porcelain Berry (Ampelopsis brevipedunculata)
    • Tree-of-Heaven or Ailanthus (Ailanthus altissima)

    Read about Autumn Olive and Porcelain Berry in this month’s Tasks & Tips article: September in the Ornamental Garden.

    Identifying Autumn Olive

    Identifying Porcelain Berry

    Now is the time to start looking out for the bright berries of the porcelain berry. Reduce its spread by preventing flowering and fruiting. This video can help you identify it:

    Porcelain berry by Leslie J. Mehrhoff, Bugwood.org

    Control of Porcelain Berry: “Herbicidal foliar treatment is most effective when applied between midsummer and early fall. Cut-stump bigger vines, applying an herbicide immediately to the cut. If you can reach the largest stems in the tangle, use a basal bark application.” — Invasive Plant Control Calendar, The Garden Shed (May 2022)

    Controlling Autumn Olive

    Autumn olive is difficult to eradicate once it reaches a certain size. It usually takes several years to completely kill the roots. If dealing with large ones, at least cut the flowers and berries. Foliar herbicide applications are recommended in summer through September. As autumn progresses, stored sugars begin to move toward the roots, making cut-stump applications more effective.

    Watch: Expert guide on how to control Autumn Olive

    Tree-of-Heaven / Ailanthus

    This tree has been in the news recently as spotted lanternflies become more visible. Since the lanternfly depends on Ailanthus, removing the tree helps control the pest. Be aware that Tree-of-Heaven resembles some natives, such as sumac and walnut.

    Watch: INVASIVE ALERT – Tree-of-Heaven

    Control Methods – Blue Ridge PRISM

    Foliar Spray: Effective in summer through fall for seedlings and small trees. Avoid spraying desirable plants.

    Basal Bark: For trunks 4–6 inches wide, use an oil-based herbicide from July to late summer or late winter to early spring. Spray around the base.

    Hack & Squirt: For large trees, make cuts with a hatchet at waist height, spaced 2 inches apart. Apply concentrated herbicide in the cuts immediately. Best from June to October.

    Cut Stump: Cutting live Ailanthus causes resprouting. If felled, treat the stump with a water-soluble herbicide immediately.

    Follow up with foliar or basal treatments to kill suckers and new seedlings.

    — Blue Ridge PRISM Tree-of-Heaven Fact Sheet


    Non-Native Invasive Plant Species Control Treatments

    Pesticide Warning

    Pesticides (including herbicides, insecticides, rodenticides, etc.) are poisonous. Always follow safety precautions on the label. Store chemicals in their original containers in a locked cabinet, away from children, pets, and food. Pesticides can contaminate waterways. Prevent runoff and avoid drift.

    Learn more:
    Reading Pesticide Labels |
    Preventing Water Contamination

    Weed Alerts & More

    If you’re still seeing Japanese stiltgrass, pull it before it drops seeds! Read the latest alert: Blue Ridge PRISM – Stiltgrass Alert

    Sign up for Weed Alerts and newsletters from Blue Ridge PRISM: Subscribe here.

    Sources