By JIMMY ROGERS
Soon, Maryland garden centers should no longer be able to sell invasive plants like English ivy (Hedera helix).
A plant species is considered invasive if it is nonnative to an area and causes human, ecological or financial harm.
Invasive vines like English ivy and porcelain berry (Ampelopsis glandulosa) carpet the ground and climb up trees, smothering forests. Japanese barberry (Berberis thunbergii), which grows equally well in full sun or deep shade, carpets large natural areas with thorny stems and creates perfect conditions for the ticks that spread Lyme disease.
Under a state law enacted in 2011, plants considered invasive in Maryland are listed in two categories: Tier 1 (prohibited) or Tier 2 (signage required). Only six species in the state are listed as Tier 1 and only 13 as Tier 2. These low numbers stand in stark contrast to the hundreds of plant species considered to be invasive by the Maryland
Invasive Species Council, a nonprofit established in 2000 to address issues related to invasive species in the state. Additionally, Tier 2 plants such as heavenly bamboo (Nandina domestica) and Japanese barberry are still sold in great numbers, despite black and yellow signs warning customers that these plants are invasive. “Plant with caution,” the signs say in bold, capped letters with exclamation points included for emphasis.
The notion that a typical gardener could plant an invasive species with sufficient caution for it not to spread is questionable; indeed, planting an invasive species in a home garden all but guarantees that wind, water and birds will spread seeds and other plant material into wild areas. Consequently, the most popular invasive ornamental plants are easily found in the woods and meadows surrounding residential areas. Home gardens continuously spread these plants, thwarting efforts, often by volunteers, to remove invasives.
Last year the Maryland Native Plant Coalition drafted a new invasive plant bill to do away with the tier system and ban more species, including invasive aquatic plants. The coalition combines the resources of the Maryland Native Plant Society, Green Towson Alliance, Sierra Club Maryland Chapter, Wild Ones Greater Baltimore chapter and Garden Clubs of America Zone 6 to bring issues concerning native plants to the attention of state lawmakers.
In its draft bill, the coalition proposed a single list of harmful plants with no option to sell them in the state. The coalition’s legislation would also introduce a new, more efficient means of evaluating harmful plants quickly. Plant Invaders of the Mid-Atlantic Natural Areas, a field guide by Jil Swearingen (et al), lists 92 species that could be readily assessed using this new process.
State Delegate Linda Foley (District 15) and State Sen. Ben Brooks sponsored the bill (jointly filed as HB979 and SB915) and shepherded it through their respective environmental committees. After some amendment of how long growers would have to transition, the Maryland Green Industry Council, which represents the interests of nurseries, joined those testifying in favor of the bill. The Maryland Department of Agriculture also voiced support once it was confirmed that the new budget would provide personnel for implementation of the changes. The legislation passed in both chambers in March 2024, and Gov. Wes Moore signed it into law on May 9. It took effect on June 1, and the new regulations must be adopted by the state’s secretary of agriculture by Oct. 1 of this year.
Under the law, when a plant is classified prohibited, sellers will have one year (two years for woody plants grown directly in the ground) to sell their stock before the plant is banned from being sold. This means top priority species like English ivy could start disappearing from store shelves as soon as the fall of 2025 or sooner, if sellers choose to get ahead of the deadlines.