Growing your own food can be rewarding, but in Iowa, some plants are off-limits. State laws restrict certain crops due to agricultural concerns, invasive potential, or public safety issues.
Before starting your garden this season, check out these surprising plants that could land you in trouble with Iowa authorities.
1. Giant Hogweed
This towering plant with white umbrella-shaped flower clusters might look impressive, but it’s strictly prohibited throughout Iowa. Contact with its sap causes severe burns when exposed to sunlight.
Originally brought to America as an ornamental curiosity, giant hogweed can grow up to 14 feet tall and spread aggressively. The Department of Agriculture actively works to eradicate any sightings to protect public health.
2. Wild Marijuana
Despite neighboring states legalizing cannabis for various uses, wild marijuana remains completely illegal to cultivate in Iowa backyards. Law enforcement doesn’t distinguish between intentional growing and allowing wild plants to flourish on your property.
Even with CBD’s rising popularity, Iowa maintains strict regulations. Penalties for cultivation can include hefty fines and potential jail time depending on the amount discovered.
3. Chinese Water Spinach
Known for its hollow stems and arrow-shaped leaves, Chinese water spinach (Ipomoea aquatica) is banned as a federal noxious weed. Though popular in Asian cuisine, it’s considered too invasive for Iowa waterways.
The plant can grow up to four inches daily in ideal conditions! Its rapid spread chokes out native vegetation and disrupts aquatic ecosystems. Even contained garden growing is prohibited to prevent accidental introduction to local water systems.
4. Opium Poppies
Many gardeners are surprised to learn that those beautiful papaver somniferum poppies are actually illegal to cultivate in Iowa. The same plant that produces innocent poppy seeds for your muffins also produces opium.
Law enforcement typically doesn’t target ornamental gardens, but technically, growing these poppies violates state and federal law. The distinctive seed pods contain alkaloids used to make morphine and other controlled substances, making them a controlled plant.
5. Purple Loosestrife
Once sold as an ornamental perennial, purple loosestrife is now banned throughout Iowa. Its vibrant purple flower spikes might catch your eye, but they signal an ecological disaster.
A single plant produces over two million seeds annually! When it invades wetlands, it forms impenetrable stands that displace native plants and destroy wildlife habitat. Iowa’s Department of Natural Resources actively removes existing populations to protect the state’s biodiversity.
6. European Buckthorn
European buckthorn might seem like an innocent shrub, but it’s classified as a noxious weed in Iowa for good reason. The fast-growing woody plant forms dense thickets that overwhelm native vegetation.
Birds spread its berries widely, allowing it to invade natural areas rapidly. Its thorny branches create impenetrable barriers, while its leaves contain chemicals that prevent other plants from growing nearby. Removal requires persistent effort as it readily resprouts from cut stumps.
7. Japanese Barberry
With its attractive red foliage and ability to thrive in shade, Japanese barberry was once a landscape favorite. Now it’s prohibited in Iowa gardens due to its aggressive spread into natural areas.
Research shows these thorny bushes create perfect humidity conditions for ticks that carry Lyme disease, increasing tick populations by 300%! The plant’s berries are spread by birds, allowing it to rapidly colonize woodlands and displace native understory plants essential for wildlife.
8. Himalayan Blackberry
Unlike their tamer cultivated cousins, Himalayan blackberries are classified as noxious weeds in Iowa. Their delicious berries hide a seriously invasive nature that’s banned from backyard cultivation.
These robust canes form impenetrable thickets up to 15 feet tall with vicious thorns that can puncture tractor tires! They spread aggressively through birds, animals, and runners, quickly overtaking pastures and natural areas. Once established, they’re extraordinarily difficult to eradicate.
9. Multiflora Rose
Originally introduced for erosion control and living fences, multiflora rose is now prohibited throughout Iowa. Its clusters of small white flowers may look charming, but they lead to serious ecological problems.
A single plant can produce up to a million seeds that remain viable in soil for 20 years! Its arching, thorny canes form dense thickets up to 15 feet tall. Iowa farmers spend millions annually battling this invasive plant that reduces grazing land and crowds out native species.
10. Palmer Amaranth
Palmer amaranth might look like an ordinary weed, but it’s actually one of Iowa’s most feared agricultural threats. This aggressive pigweed species is banned from intentional cultivation and must be reported if found.
A single plant produces up to 500,000 seeds! Even more alarming, it can grow 2-3 inches daily and has developed resistance to multiple herbicides. Iowa farmers face significant crop losses when this invader establishes in fields, making its control a top priority for the state’s agriculture department.
11. Garlic Mustard
Despite its culinary-sounding name, garlic mustard is strictly prohibited in Iowa gardens. This invasive biennial produces small white flowers and heart-shaped leaves that emit a garlic odor when crushed.
What makes it especially dangerous is its ability to produce chemicals that prevent other plants from growing nearby. It rapidly colonizes woodland areas, displacing native wildflowers and tree seedlings. Iowa conservation groups regularly organize volunteer pulls to combat its spread in natural areas.