Wormseed: Understanding This Non-Native Annual Herb
If you’ve ever noticed a strongly aromatic, weedy-looking plant popping up in disturbed areas around your garden, you might have encountered wormseed (Dysphania anthelmintica). This non-native annual herb has quite the journey story—originally from Central and South America, it has now made itself at home across much of the United States. While it’s not your typical garden showstopper, understanding this plant can help you make informed decisions about your landscape.
What Exactly is Wormseed?
Wormseed is an annual forb, which simply means it’s a non-woody herbaceous plant that completes its entire life cycle in one growing season. You might also see it listed under its former scientific names, including Chenopodium anthelminticum—botanists love to shuffle plant names around! This fast-growing plant typically reaches 1-4 feet tall and spreads about 1-2 feet wide.
The plant gets its common name from its historical use as an herbal remedy for intestinal worms, though we definitely don’t recommend trying this at home. Its leaves are serrated and quite aromatic when crushed, producing a rather pungent, medicinal smell that’s quite distinctive.
Where You’ll Find Wormseed
As a non-native species that’s been introduced to North America, wormseed has established itself across 26 states, from Alabama to West Virginia. It’s particularly common in disturbed soils, vacant lots, roadsides, and sometimes in cultivated areas where it wasn’t invited.
Should You Grow Wormseed in Your Garden?
Here’s the honest truth: wormseed isn’t typically grown as an ornamental plant, and there are several reasons why you might want to think twice about intentionally planting it:
- Limited aesthetic appeal: Its small, greenish flowers are fairly inconspicuous and won’t add much visual interest to your landscape
- Weedy nature: This plant tends to self-seed readily and can pop up where you don’t want it
- Strong aroma: While some find the scent interesting, others find it quite off-putting
- Non-native status: As gardeners, we have the opportunity to support native ecosystems
Better Native Alternatives
Instead of wormseed, consider these native alternatives that offer similar growing characteristics but provide better support for local wildlife:
- Wild bergamot (Monarda fistulosa): Aromatic native herb with showy flowers that pollinators adore
- American burnweed (Erechtites hieraciifolius): Annual native that thrives in disturbed soils
- Lamb’s quarters (Chenopodium album): While also weedy, this species is native and edible
If You Encounter Wormseed
If wormseed shows up in your garden uninvited (which it might), here’s what you need to know about its growing preferences:
- Growing conditions: Thrives in full sun to partial shade and tolerates poor, disturbed soils
- Hardiness: Hardy in USDA zones 4-10 as an annual
- Water needs: Quite drought-tolerant once established
- Soil preferences: Not picky about soil quality—actually seems to prefer disturbed or poor soils
Managing Wormseed
If you decide you don’t want wormseed in your garden, the best approach is to remove it before it sets seed. Since it’s an annual, preventing reproduction is key to managing its spread. Pull plants when soil is moist, and be sure to get the entire root system.
The bottom line? While wormseed isn’t harmful to have around, it’s not bringing much to the party in terms of supporting native wildlife or adding beauty to your landscape. Your garden space is precious—why not fill it with plants that truly earn their keep by feeding pollinators, supporting birds, and creating the stunning native landscapes our ecosystems need?
