Maine gardeners may be surprised that a few familiar plants are edging toward the restricted list. I came across one at a local nursery and had no clue it was under review.
These rules shift faster than most people expect. Keeping an eye on potential changes helps you avoid planting something that disappears from the rulebook later.
1. Japanese Barberry
Bright red berries make this shrub look festive, but wildlife experts worry it creates perfect hiding spots for deer ticks. Maine officials are concerned because these ticks spread Lyme disease, which affects thousands of people each year.
The plant spreads quickly through yards and forests, pushing out native species that local animals depend on. Garden centers across Maine still sell it, though some towns already discourage planting it.
Homeowners should consider native alternatives that beautify landscapes without creating health risks for families and pets.
2. Purple Loosestrife
Those gorgeous purple spikes along Maine wetlands might seem harmless, but a single plant produces millions of seeds annually. Waterfowl lose critical food sources when this aggressive invader takes over marshes and stream banks.
Already banned in several states, Maine regulators are watching its spread closely. The roots grow so thick that native cattails and bulrushes cannot compete for space or nutrients.
Removing established plants requires digging deep to prevent regrowth, making prevention the smartest strategy for Maine property owners.
3. Norway Maple
Suburban streets throughout Maine feature these shade trees, yet their dense canopy blocks sunlight so effectively that grass struggles to grow underneath. Sugar maples, which produce the syrup Maine is famous for, face tough competition from this European import.
Seedlings pop up everywhere, quickly dominating forests and parks. The shallow roots also crack sidewalks and foundations, creating expensive repair bills for homeowners.
Native oak or red maple trees provide better shade without threatening Maine’s ecological balance or infrastructure.
4. Burning Bush
Fall foliage fans adore the scarlet leaves this shrub produces, creating stunning autumn displays across Maine neighborhoods. Birds eat the berries and spread seeds into wild areas where the plant outcompetes native vegetation that provides better nutrition for wildlife.
Massachusetts already restricts sales, and Maine conservation groups want similar rules. The shrub adapts to various soil types, making containment nearly impossible once established.
Blueberry bushes offer equally beautiful fall color while supporting Maine’s agricultural heritage and local ecosystems.
5. Multiflora Rose
Farmers once planted this thorny rose as living fences, but the decision backfired spectacularly across rural Maine. Dense thickets now block pastures and hiking trails, with thorns sharp enough to tear clothing and skin.
Each plant produces thousands of rose hips that birds spread far and wide. Removing established patches requires heavy equipment and persistent effort over several years.
Maine landowners face costly removal projects, and legislators are considering bans to prevent further spread throughout the state’s countryside.
6. Glossy Buckthorn
Shiny leaves and adaptability to wet or dry soil made this shrub a landscaping favorite, but Maine forests are paying the price. Songbirds that eat the berries suffer nutritional deficiencies because the fruit lacks essential vitamins found in native plants.
The shrub also alters soil chemistry, making it harder for wildflowers and tree seedlings to establish. Some Maine nature preserves spend thousands of dollars annually battling buckthorn infestations.
Winterberry holly provides similar visual appeal while supporting healthy bird populations throughout Maine.
7. Common Barberry
Yellow spring flowers attract gardeners, but agricultural officials worry this plant harbors wheat rust disease that devastates grain crops. Maine’s small farming communities cannot afford widespread crop failures caused by preventable plant diseases.
The thorny branches also create impenetrable barriers in woodlands, blocking access for hikers and wildlife alike. Birds spread the seeds rapidly, establishing new colonies far from original plantings.
Native hawthorn species offer similar thorny protection for property boundaries without threatening Maine’s agricultural economy or natural areas.
8. Autumn Olive
Silver-scaled leaves shimmer beautifully in sunlight, and wildlife managers initially promoted planting for erosion control across Maine. Decades later, the mistake is obvious as the shrub dominates old fields and forest edges.
The nitrogen-fixing roots actually change soil chemistry, making habitats unsuitable for native plants that evolved in Maine’s naturally acidic soils. Birds spread the abundant berries everywhere, creating new infestations constantly.
Native serviceberry provides similar wildlife food without transforming Maine’s distinctive forest ecosystems or outcompeting valuable native species.
9. Oriental Bittersweet
Craft enthusiasts love the orange and red berries for fall decorations, but Maine’s trees are suffering under the weight of these aggressive vines. Mature trees can be completely smothered, dying from lack of sunlight and structural damage.
The vines grow so vigorously that they snap branches and topple weakened trees during storms. Native American bittersweet, a look-alike species, is being displaced throughout Maine forests.
Purchasing cultivated decorative branches instead of harvesting wild vines helps protect Maine’s forest canopy from this destructive invader.
10. Dame’s Rocket
Roadside ditches across Maine explode with purple and white blooms each spring, and many people mistake this plant for native phlox. Garden seed mixes often include it, but conservation groups want Maine to restrict sales before infestations worsen.
The plant self-seeds aggressively, crowding out wildflowers that provide better nutrition for native pollinators. Its rapid spread threatens rare plant communities in Maine’s wetlands and meadows.
True native phlox species bloom just as beautifully while supporting the butterflies and bees that Maine’s ecosystems depend on.
11. Yellow Iris
Pond edges throughout Maine showcase these cheerful yellow blooms, but the plants form dense mats that choke out native vegetation. Waterfowl nesting sites disappear as the iris takes over shorelines and shallow water areas.
The thick roots trap sediment, gradually filling in ponds and altering water flow patterns. Several northeastern states already prohibit planting near waterways because removal is so difficult and costly.
Maine’s blue flag iris offers similar beauty while supporting healthy wetland ecosystems that benefit fish, frogs, and countless other native species.
12. Garlic Mustard
White spring flowers blanket Maine forest floors, releasing a distinct garlic smell when crushed underfoot. Wildflower enthusiasts recognize this European import as a serious threat to native spring ephemerals that feed emerging butterflies.
The plant produces chemicals that poison soil fungi, harming tree roots that depend on these underground partners. A single plant generates thousands of seeds that remain viable for years in soil.
Hand-pulling before seed formation helps, but Maine communities need coordinated efforts to prevent this aggressive invader from destroying forest biodiversity.
13. European Frogbit
Tiny floating leaves resembling miniature lily pads look innocent, but this aquatic plant can completely cover Maine ponds within a single growing season. Sunlight cannot penetrate the dense mats, killing underwater plants that fish depend on for food and oxygen.
Boaters accidentally spread fragments to new water bodies on trailers and equipment. Once established, the plant survives winter as dormant buds that sink to the bottom.
Maine lake associations are pushing for possession bans before this aggressive invader reaches more of the state’s precious freshwater resources.