Bishop Weed: Most Hated Plants Bishop’s Weed Ajava Seeds, Ajowan, Ajowan Caraway, Ajowan Seed, Ajowanj, Ajwain, Ajwan, Ameo Bastardo, Ammi Commun, Ammi Élevé, Ammi glaucifolium, Ammi Inodore, Ammi majus, Ammi Officinal, Although it has extremely vigorous growth and invasive tendencies, bishop's weed is useful in the right setting.
Bishop Weed: Most Hated Plants
I’d like to dedicate this post to my blogging friend, Carol at Flower Hill Farm, for her long-suffering with this invasive plant, her nemesis, Bishop Weed, also known as Goutweed (Aegopodium podagraria).
But first, a disclaimer. I call this ongoing series “Most Hated Plants,” but some have taken issue with “hating” poor defenseless plants. Most Hated Plants is really a shorhand way of saying:
- I don’t really hate the plants.
- I do hate that nurseries continue to propagate and sell these plants
- I hate that landscapers continue to install them
- And I hate that people continue to plant them
- Invasive plants are wiping out native habitats leaving wildlife no place to go
- Invasive plants cost taxpayers $138 BILLION dollars every year
- I really would like to see homeowners do their homework prior to purchasing ANY plant
But instead of saying all of that every time I refer to the damage caused by invasive plants, I simply say MOST HATED PLANTS as my short hand.
Bishop Weed is native to Europe, northern Asia, and Siberia and was brought to this country as an ornamental plant. It was first noticed to have escaped cultivation and become invasive in Rhode Island in 1863.
Also known as Goutweed, it wreaks havoc in moist, partly shaded woodlands and disturbed areas. It forms a dense mat that prohibits other plants from establishing.
This trait is especially harmful in natural wooded areas where it outcompetes native plants. Because of this, many native woodland plants are now highly endangered.
I’ve been attempting to rid my property of this plant since 2001 when I first moved in. It feels like a losing battle because it returns with a vengeance especially after the rain. We pull, and we pull, and then we pull some more. But it always comes back.
That’s because Bishop Weed not only spreads by seed, it also spreads by underground runners. If you’re pulling but don’t get every last piece of those runners out of the ground, it will pop up again almost immediately.
My neighbor across the street is the head propagator for Morris Arboretum. Her garden is her own beautiful private botanic garden. Really, it’s stunning! But she has been battling Goutweed for the 30 years she’s lived in her house. Trust me, she REALLY hates this plant!
Risa Edlestein, my blogging buddy at Garden and the Good Life, has started a discussion on the best ways to eliminate this invasive plant from the landscape at the Ecological Landscaping Association Group on LinkedIn.
It is banned for sale in Connecticut, Massachusetts, and Vermont, and is considered a noxious pest from Eastern Canad to Georgia and into the midwest, plus is invasive in the Pacific Northwest.
A much better alternative to this noxious, invasive plant is the native Golden Alexanders (Zizea aurea), in the same family as Bishop Weed, but a much gentler inhabitant of native ecosystems, and a host plant for Black Swallowtail butterfly caterpillars.
So, Carol, this one’s for you, in hopes that you will make headway in this battle!
Ajava Seeds, Ajowan, Ajowan Caraway, Ajowan Seed, Ajowanj, Ajwain, Ajwan, Ameo Bastardo, Ammi Commun, Ammi Élevé, Ammi glaucifolium, Ammi Inodore, Ammi majus, Ammi Officinal, Bishop’s Flower, Bisnague, Bullwort, Carum, Espuma del Mar, Flowering Ammi, Grand Ammi, Omum, Yavani.
Bishop’s weed is a plant. The seeds are used to make medicine.
The prescription drug methoxsalen (Oxsoralen, Methoxypsoralen) was originally prepared from bishop’s weed, but it is now made in the laboratory. Methoxsalen is used to treat psoriasis, a skin condition.
Bishop’s weed is used for digestive disorders, asthma, chest pain (angina), kidney stones, and fluid retention.
Some people apply bishop’s weed directly to the skin for skin conditions including psoriasis and vitiligo.
Be careful not to confuse bishop’s weed (Ammi majus) with its more commonly used relative, khella (Ammi visnaga). The two species do contain some of the same chemicals and have some similar effects in the body. But Bishop’s weed is more commonly used for skin conditions, and khella is usually used for heart and lung conditions.
How does it work?
Bishop’s weed contains several chemicals, including methoxsalen, a chemical used to make a prescription medication for the skin condition psoriasis.
Uses & Effectiveness
Insufficient Evidence to Rate Effectiveness for.
- Skin conditions such as psoriasis and vitiligo.
- Digestive problems.
- Chest pain.
- Kidney stones.
- Fluid retention.
- Other conditions.
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).
There isn’t enough information to know if bishop’s weed is safe. When taken by mouth, bishop’s weed might cause nausea, vomiting, and headache. Some people are allergic to bishop’s weed. They can get a runny nose, rash, or hives. There is also some concern that bishop’s weed might harm the liver or the retina of the eye.
Bishop’s weed can cause skin to become extra sensitive to the sun. This might put you at greater risk for skin cancer. Wear sunblock outside, especially if you are light-skinned.
Special Precautions & Warnings
Pregnancy and breast-feeding: It’s UNSAFE to use bishop’s weed if you are pregnant. It contains a chemical called khellin that can cause the uterus to contract, and this might threaten the pregnancy.
It’s also best to avoid using bishop’s weed if you are breast-feeding. There isn’t enough information to know whether it is safe for a nursing infant.
Liver disease: There is some evidence that bishop’s weed might make liver disease worse.
Surgery: Bishop’s weed might slow blood clotting. There is a concern that it might increase the risk of bleeding during and after surgery. Stop using bishop’s weed at least 2 weeks before a scheduled surgery.
Medications changed by the liver (Cytochrome P450 3A4 [CYP3A4] substrates)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some medications are changed and broken down by the liver. Bishop’s weed might decrease how quickly the liver breaks down some medications. Taking bishop’s weed along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking bishop’s weed, talk to your healthcare provider if you are taking any medications that are changed by the liver.
Some medications changed by the liver include lovastatin (Mevacor), ketoconazole (Nizoral), itraconazole (Sporanox), fexofenadine (Allegra), triazolam (Halcion), and many others.
Medications that can harm the liver (Hepatotoxic drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Bishop’s weed might harm the liver. Taking bishop’s weed along with medication that might also harm the liver can increase the risk of liver damage. Do not take bishop’s weed if you are taking a medication that can harm the liver.
Some medications that can harm the liver include acetaminophen (Tylenol and others), amiodarone (Cordarone), carbamazepine (Tegretol), isoniazid (INH), methotrexate (Rheumatrex), methyldopa (Aldomet), fluconazole (Diflucan), itraconazole (Sporanox), erythromycin (Erythrocin, Ilosone, others), phenytoin (Dilantin), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and many others.
Medications that increase sensitivity to sunlight (Photosensitizing drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some medications can increase sensitivity to sunlight. Bishop’s weed might also increase your sensitivity to sunlight. Taking bishop’s weed along with medication that increases sensitivity to sunlight could increase the chances of sunburn, blistering, or rashes on areas of skin exposed to sunlight. Be sure to wear sunblock and protective clothing when spending time in the sun.
Some drugs that cause photosensitivity include amitriptyline (Elavil), Ciprofloxacin (Cipro), norfloxacin (Noroxin), lomefloxacin (Maxaquin), ofloxacin (Floxin), levofloxacin (Levaquin), sparfloxacin (Zagam), gatifloxacin (Tequin), moxifloxacin (Avelox), trimethoprim/sulfamethoxazole (Septra), tetracycline, methoxsalen (8-methoxypsoralen, 8-MOP, Oxsoralen), and Trioxsalen (Trisoralen).
Medications that slow blood clotting (Anticoagulant/Antiplatelet drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Bishop’s weed might slow blood clotting. Taking bishop’s weed along with medications that also slow clotting might increase the chances of bruising and bleeding.
Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.
The appropriate dose of bishop’s weed depends on several factors such as the user’s age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for bishop’s weed. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Health Solutions From Our Sponsors
Dollahite, J. W., Younger, R. L., and Hoffman, G. O. Photosensitization in cattle and sheep caused by feeding Ammi majus (greater Ammi; Bishop’s-Weed). Am J Vet.Res 1978;39(1):193-197. View abstract.
EL MOFTY, A. M. Observations on the use of Ammi majus Linn. In vitiligo. Br J Dermatol 1952;64(12):431-441. View abstract.
EL MOFTY, A. M., el Sawalhy, H., and el Mofty, M. Clinical study of a new preparation of 8-methoxypsoralen in photochemotherapy. Int J Dermatol 1994;33(8):588-592. View abstract.
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Singh, U. P., Singh, D. P., Maurya, S., Maheshwari, R., Singh, M., Dubey, R. S., and Singh, R. B. Investigation on the phenolics of some spices having pharmacotherapeuthic properties. J Herb.Pharmacother. 2004;4(4):27-42. View abstract.
Abdel-Fattah A, Aboul-Enein MN, Wassel GM, El-Menshawi BS. An approach to the treatment of vitiligo by khellin. Dermatologica 1982;165:136-40. View abstract.
Ahsan SK, Tariq M, Ageel AM, et al. Effect of Trigonella foenum-graecum and Ammi majus on calcium oxalate urolithiasis in rats. J Ethnopharmacol 1989;26:249-54. View abstract.
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Viveka Neveln is the Garden Editor at BHG and a degreed horticulturist with broad gardening expertise earned over 3+ decades of practice and study. She has more than 20 years of experience writing and editing for both print and digital media.
Bishop’s Weed Overview
|Description||Although it has extremely vigorous growth and invasive tendencies, bishop’s weed is useful in the right setting. If you are looking for an easy-to-grow groundcover to quickly fill a confined space, consider this plant. Its attractive light green foliage edged in cream looks nice all season long in part shade to full shade. Airy panicles of white blooms emerge above the foliage in summer.|
|Genus Name||Aegopodium podagraria|
|Common Name||Bishop’s Weed|
|Light||Part Sun, Shade|
|Height||6 to 12 inches|
|Season Features||Summer Bloom|
|Special Features||Good for Containers, Low Maintenance|
|Zones||3, 4, 5, 6, 7, 8, 9|
|Problem Solvers||Deer Resistant, Drought Tolerant, Groundcover, Slope/Erosion Control|
Worth the Risk?
Bishop’s weed—as you might guess by the name—is a plant gardeners love to hate (after all, they named it a weed). When introduced in the eastern United States as an ornamental plant, people loved its ease of growth and vigor. It helped that the plant had attractive foliage. Because it is extremely easy to share as a simple division or clipping from the garden, it became a common pass-along plant and quickly made its way into ornamental gardens. Eventually, people realized the mistake: Once planted, it can be nearly impossible to eradicate. The vigorous growth habit, coupled with its quick regeneration and copious seed production, make this plant a beast to control. For these reasons, it is important to think long and hard before planting bishop’s weed. Even then, it should only be planted in confined areas like between a sidewalk and a house where it has solid physical boundaries.
Bishop’s Weed Care Must-Knows
As the name implies, bishop’s weed is an extremely easy plant to grow, even in harsh conditions. Ideally, it likes consistently moist, well-drained soil, although it can take some drought. During long dry spells, the foliage, especially of variegated species, tends to crisp and burn.
For the best-looking foliage, plant it in part sun. This ensures that the plants get enough light to have nice variegation but also protects their sensitive leaves from burning. The plant’s vigorous nature means it grows fine in full shade or even full sun.
If your plants begin to look a little ragged, mow them back to encourage a new flush of growth. It’s also a good idea to remove any seed heads after blooming to control spreading. Other than leaf blight in the heat and drought of the summer, these plants are fairly untouched by pests and disease.
Generally speaking, gardeners end up more concerned about removing the plant, which is much easier said than done. You must dig up the underground rhizomes without leaving even the smallest piece behind.
Manual removal of the plants is tedious and may need to be repeated until all of the plants are removed. They also are tough enough to survive several applications of harsh herbicides.
The best method of eradication is solarization: Cut back the plants and cover the bed with black plastic for a whole growing season to block out any sunlight and to raise the temperature of the soil.