Crested late summer mint, Vietnamese balm
(Elsholtzia ciliata)
Biological Category
Plants
NY Legal Status
Not Regulated
Species Type
Other Herbaceous
DESCRIPTION
Crested late summer mint is a member of the Mint family (Lamiaceae).
A shallow-rooted annual in the mint family, Crested late summer mint, can grow up to three feet in height, given the right conditions. This strongly scented species is most conspicuous in late summer when plants produce distinctive one-sided spikes of pale blue flowers.
Note: Research for these pages was generated from citations listed. References for specific statements available upon request.
Leaves: Leaves are oppositely arranged along hairy stems, oval to lance shaped and one to three inches long with wrinkled to serrate margins.
Flowers: Flowers are pale blue, classic zygomorphic, tubular mint family flowers and appear in late summer through early fall on tall, one-sided spikes.
The first record of Crested late summer mint in North America dates back to 1887, although how and why it arrived here from its native Asia is not known. The species is now extant in at least thirteen states, although its potential expansion range covers many more.
Crested late summer mint prefers moist, freely-draining soil and is often found in exposed areas with gravelly or sandy soil such as railroad beds, vacant lots, and roadsides. In New York, this species has been found in exposed, disturbed riparian areas.
Crested late-summer mint is pollinated by insects and appears to have very high rates of germination. Vectors include mechanical dispersal via mammals, machinery, and other human activities.
Little is known about the ecological impacts of Crested late summer mint. In fact, by and large, the invasive status of this species is still under question. Several reports of this species aggressively colonizing areas across the Northeast and Midwest indicate Crested late summer mint could become a problematic invasive given time. The large, dense stands this species is capable of forming can cause alterations in the diversity and heterogeneity of the communities it invades.
There is no biological control agent available at this time.
Pulling / Digging Up: No information available
Mowing: No information available. As a weak-rooted annual it is reasonable to assume pulling is effective on small populations.
Girdling: Not applicable
Prescribed Fire: No information available
Prescribed Grazing: No information available
Soil Tilling: No information available
Mulching: No information available
Solarization: No information available
Hot Foam Spray: No information available
The pesticide application rates and usage herein are recommendations based on research and interviews with land managers. When considering the use of pesticides, it is your responsibility to fully understand the laws, regulations and best practices required to apply pesticides in a responsible manner. At times, the pest you seek to treat may not be on a pesticide label, requiring a 2ee exemption from NYSDEC. Always thoroughly read the label of any pesticide and consult the NYSDEC or a licensed pesticide applicator with questions.
Foliar Spray: A 1-2% foliar spray during growing season is probably effective. Always read and follow all directions on the herbicide label and take care when applying in wet areas.
Cut Stump: Not applicable
Basal Bark: Not applicable
Stem Injection: Not applicable
Pre-Emergent Spray: No information available
As with any other invasive infestation complex, Crested late summer mint is best managed via a combination of mechanical and chemical means. All managed infestations should be monitored for at least one year to manage any germination of new seedlings that occurs. As management of this species is still under study, be careful to prevent the spread of seed by practicing boot brushing.
Post-treatment monitoring: Controlled populations should be revisited for several years to ensure no germination of new seedlings has occurred.
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