Many Maryland gardeners are surprised to learn that their backyard hobby could lead to legal headaches. It’s not just about what thrives in the soil—but what’s allowed by law. Even well-meaning planting choices can cross the line.
State rules, agricultural policies, and Maryland’s unique climate form a tricky landscape for home growers. Some plants pose risks to ecosystems, public health, or local farms. That’s why certain species are tightly controlled—or outright banned.
Whether it’s due to invasive behavior, toxic traits, or ties to controlled substances, these plants are off-limits or heavily regulated. Knowing what’s forbidden can save you trouble—and help protect Maryland’s natural balance.
1. Opium Poppy
Growing these delicate-looking flowers might seem innocent, but they’re classified as Schedule II controlled substances under federal law. Maryland authorities take their cultivation seriously.
The seeds sold in grocery stores for baking are legal, but once you plant them, you’ve broken the law. Many gardeners unknowingly violate regulations while attempting to grow ornamental varieties.
I once mistakenly purchased poppy seeds at a garden center, not realizing the legal implications until a neighbor pointed it out. Even small amounts grown for decorative purposes can result in serious legal consequences.
2. Coca Plant
Federal regulations strictly prohibit growing this South American native in any U.S. state, including Maryland. The plant contains alkaloids used to produce cocaine, making it a Schedule II controlled substance.
Despite its tropical appearance and attractive red berries, possession of even a single plant can result in felony charges. Maryland’s climate isn’t naturally suited for coca growth, but indoor cultivation attempts still occur.
Law enforcement agencies actively monitor unusual plant imports and specialized growing equipment that might indicate coca cultivation. The penalties far outweigh any botanical curiosity about this controversial plant.
3. Salvia Divinorum
Maryland banned this psychoactive sage in 2010, making it illegal to grow, possess, or distribute. The plant produces powerful hallucinogenic effects when consumed, placing it on the state’s controlled substances list.
Before the ban, some Maryland gardeners grew it alongside common kitchen herbs, unaware of its powerful properties. The mint family relative looks unremarkable but contains salvinorin A, one of the most potent naturally occurring psychedelics.
Enforcement has increased in recent years after several incidents involving teenagers experimenting with the plant. Though some neighboring states have looser regulations, Maryland maintains strict prohibition on backyard cultivation.
4. Khat
Native to East Africa and the Arabian Peninsula, khat contains cathinone, a stimulant that’s classified as a Schedule I controlled substance. Maryland follows federal prohibitions against growing this plant.
Some immigrant communities from regions where khat is traditionally used have attempted backyard cultivation, leading to legal issues. The plant resembles ordinary shrubs, making detection challenging for authorities.
Maryland’s climate actually suits khat growth during summer months. The DEA has conducted several operations targeting khat distribution networks in the Baltimore-Washington corridor, demonstrating the seriousness with which violations are treated.
5. Absinthe Wormwood
The infamous plant used to make absinthe contains thujone, a compound restricted by the FDA. Maryland follows federal guidelines prohibiting the cultivation of high-thujone varieties intended for consumption.
Gardeners sometimes confuse ornamental wormwood varieties with the prohibited Artemisia absinthium used for the alcoholic beverage. The silvery-leaved plant has a long history of controversy dating back to its alleged psychoactive effects.
Maryland’s Department of Agriculture monitors suspicious cultivation, especially commercial-scale operations. While small ornamental specimens might fly under the radar, growing this plant specifically for absinthe production violates both state and federal regulations.
6. Peyote Cactus
Federal law classifies peyote as a Schedule I controlled substance, making it illegal to grow in Maryland backyards. The small, button-shaped cactus contains mescaline, a powerful hallucinogen.
Religious exemptions exist for members of the Native American Church, but these don’t extend to home gardeners. Maryland authorities coordinate with federal agencies to enforce prohibitions against cultivation.
The slow-growing cactus takes years to mature, but possession at any stage of development remains illegal. Some cactus enthusiasts have unknowingly purchased peyote mixed in with legal cactus collections, creating unintentional legal exposure.
7. Water Spinach
Surprisingly, this common Asian vegetable (Ipomoea aquatica) is classified as a federal noxious weed, making it illegal to grow in Maryland without special permits. Its aggressive growth threatens waterways across the state.
Maryland’s abundant wetlands make it particularly vulnerable to water spinach invasion. The plant can escape cultivation and quickly establish itself, outcompeting native species and disrupting aquatic ecosystems.
Several Asian grocery stores in Maryland have been fined for selling the plant. Despite its nutritional value and popularity in many cuisines, the environmental risks have kept this leafy green on the prohibited list for backyard gardens.
8. Citrus Quarantine Plants
Maryland enforces strict citrus quarantine laws to protect commercial agriculture from devastating diseases like citrus greening and citrus canker. Many varieties require special permits or are completely prohibited.
Bringing unauthorized citrus plants across state lines into Maryland is illegal without proper inspection and certification. Even seemingly healthy plants can harbor diseases that could threaten the region’s agricultural economy.
Maryland’s Department of Agriculture conducts regular inspections of nurseries and garden centers. Backyard gardeners who order citrus plants online from unregistered sources risk having their plants confiscated and may face fines for violating quarantine regulations.
9. Moonflower
All parts of this night-blooming beauty contain dangerous tropane alkaloids. Maryland poison control centers regularly deal with accidental poisonings, leading to restrictions on cultivation in community and school gardens.
The plant’s resemblance to edible morning glories causes confusion, especially among young children. Several Maryland counties have banned moonflower from public spaces, though private garden restrictions vary by municipality.
Maryland Master Gardeners typically advise against growing moonflower in homes with children or pets. The trumpet-shaped white flowers may be stunning in the evening garden, but the potential risks have placed this plant on watch lists throughout the state.
10. Datura
Often called jimsonweed or devil’s trumpet, this highly toxic plant is restricted in many Maryland counties, especially near schools and public parks. All parts contain dangerous levels of tropane alkaloids that can cause severe poisoning.
The plant grows wild in some areas of Maryland, but intentional cultivation is discouraged by health authorities. Every summer, Maryland poison control centers report cases of accidental exposure, particularly involving curious children and teenagers.
Local ordinances in several Maryland municipalities specifically name datura in their prohibited plants list. While enforcement typically focuses on public property, growing these plants in accessible areas of private gardens can result in nuisance violations or liability issues.
11. Hemp Without Permits
Maryland has legalized industrial hemp cultivation, but growing it without proper licensing violates state law. Backyard hemp gardeners must navigate a complex permitting process or face penalties.
The Maryland Department of Agriculture requires background checks, site plans, and regular THC testing for all hemp cultivation. Without these permits, growing even a single plant is illegal, regardless of its THC content or intended use.
During my conversation with a Maryland agricultural inspector last year, he mentioned that unauthorized hemp growing cases had increased dramatically. Many home gardeners mistakenly believe that hemp’s legal status means they can grow it freely, only to discover the strict regulatory framework too late.
12. Wild Ginseng
Harvesting wild American ginseng is tightly regulated in Maryland, and cultivation requires special permits. The valuable medicinal root faces poaching pressures that have led to strict oversight of both wild and cultivated plants.
Maryland’s Department of Natural Resources monitors ginseng populations and enforces harvest seasons. Growing this native plant without proper documentation can result in significant fines, especially if plants are harvested and sold.
The slow-growing herb takes years to reach maturity in Maryland’s forests. While some dedicated gardeners have successfully obtained permits for backyard cultivation, the regulatory hurdles are designed to protect wild populations from exploitation and ensure sustainable management practices.