Marigolds burst with color in gardens everywhere. Their vibrant yellow, orange, and red petals add excitement, and they even help keep certain bugs away.
You might think planting marigolds is all good, but what about the drawbacks?
All types of marigolds, scientifically known as Tagetes species, can irritate the skin if touched.
The North Carolina Extension Gardener Plant Toolbox lists “Contact Dermatitis” as a potential issue with Tagetes species.
What causes these skin problems from marigolds? Researchers believe chemicals called phototoxic thiophenes and sesquiterpene lactones are to blame, especially for skin reactions in mammals.
Tests on guinea pigs, detailed in a 1995 Contact Dermatitis study, found significant reactions to a compound called butenylbithiophene found in marigolds.
A 2005 European Commission report found extracts and oils from Tagetes erecta, Tagetes minuta, and Tagetes patula unsafe for use in cosmetics.
Be Cautious With Marigolds
If you’re worried about sensitive family members brushing against your garden, you might want to skip planting marigolds altogether.
If you’re not as concerned, avoid the marigold varieties known to cause the most allergies. These include Tagetes tenuifolia (also called signet or lemon marigold), Tagetes erecta (sometimes known as African or Mexican marigold), Tagetes patula (commonly called French marigold), and Tagetes lucida (also known as Mexican marigold in the U.S. or sweet mace in the U.K.).
Tagetes minuta (another African marigold) is listed as a skin irritant by the Royal Horticultural Society (RHS) in the U.K.
For detailed information, the RHS database lists over 300 Tagetes species with allergen data.
For instance, Tagetes erecta comes with a caution, but Tagetes patula (another French marigold) does not.
The naming of marigolds can be confusing. Different cultivars often share the same common name, leading to mix-ups among gardeners and nurseries.
To avoid allergenic marigolds, use the scientific name when purchasing plants or seeds.
Tips for Gardeners
Guides on marigold care often overlook the importance of protection.
Wear gloves, eye protection, socks, closed-toe shoes, long pants, and sleeves when handling marigolds.
Marigolds are generally safe for pets, but keep an eye on them if they have sensitive skin.
Allergic reactions to marigolds cause a rash that’s hard to resist scratching, sometimes with blisters or hives.
Other marigold-like plants in the U.S. can also trigger allergies and confusion. One example is the yellow marsh marigold (Caltha palustris), resembling buttercups, found in wet areas across the U.S., except the southern regions, and mildly toxic to the skin.
The desert marigold (Baileya multiradiata), a yellow-flowered shrub native to the southwestern U.S., is harmful only to goats and sheep.
Pot marigolds (Calendula officinalis) look similar to Tagetes marigolds but are safe to handle.