Any home gardener knows that pesky invasive plants can appear anytime. Here are seven invasive plants that gardeners can tackle in the spring, before they bloom and scatter seeds.
Tree of heaven. Photo by Dalgial
Tree of heaven: This fast-growing tree spreads quickly by dozens of root-suckers, re-sprouts and by producing enormous quantities of seeds. Because it can grow 10 feet a year, it’s best to identify and control it early. When they are too big to pull, contact an arborist or your local weed control program listed below.
Italian arum. Photo by H. Zell
Italian arum: To control Italian arum, carefully dig out plants as soon they are identified but expect the bulbs and roots to be buried deep. Remove orange seedpod clusters to prevent additional spread. Don’t compost any parts of the plant; toss it all in the trash. And most importantly, don’t share or swap this plant.
Spurge laurel. Photo courtesy of the City of Portland
Spurge laurel: Spurge laurel can irritate your skin and cause respiratory issues in sensitive people. Always wear gloves and cover arms and legs. The berries, leaves and bark are all poisonous; this is not a good plant to compost. Remove all berries and flowers and bag them and toss in the trash. Pull small plants in spring or winter when soils are soft. Dig out larger plants with roots that are hard to pull.
Yellow archangel. Photo by Rosser1954
Yellow archangel: Like many garden invaders, yellow archangel can spread by stems, roots and seeds and can escape to natural areas by the improper disposal of yard waste. If your plants have seeds, clip the seed heads carefully and put them in a plastic bag that can be sealed and thrown in the trash. Do not compost or put in yard debris if plants have seeds. Dig carefully in spring to remove all plant parts above and below ground.
Lesser celandine. Photo by Bob Routledge
Lesser celandine: Lesser celandine is sometimes misidentified as the native marsh marigold. If you have a small infestation, you may be able to dig and gather all the small bulbs and tubers. Do not compost or put in yard debris; they should be bagged and thrown away. For larger infestations or along streams or in wetlands, contact your local weed control program for help. Digging plants in these vulnerable areas can cause soil disturbance and damage.
Pokeweed. Photo by Kathy Shearin
Pokeweed: With striking magenta stems, pokeweed may be shared by neighbors or at plant sales and swaps. It has many toxic parts. It is much easier to control pokeweed when it is small; pull or dig plants and watch for regrowth every year. Flowers, seeds and berries should be bagged and put in the garbage; other parts of the plant can be composted or disposed along with your yard debris.
Garlic mustard. Photo by Frank Mayfield
Garlic mustard: Hand pull and remove small plants; these can go in compost or yard debris. Older plants, if they have bloomed or begun to produce seed, should be bagged and put in the garbage after pulling.
Additional resources
For more information on these and other weeds, check out the 4-County Cooperative Weed Management Area.
Not sure whether something you want to plant may become a problem? The Portland Plant List provides extensive information on native and invasive plants in the area:
Need to talk with an expert? Contact your local soil and water conservation district (SWCD).
Sign up for the Backyard Habitat Certification Program.