En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Invasive horsetail in Etna NH

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.

Need help with plant identification, visit the plant identification page.
 
rate this answer
1 rating

Monday - July 27, 2009

From: Etna , NH
Region: Northeast
Topic: Invasive Plants
Title: Invasive horsetail in Etna NH
Answered by: Barbara Medford

QUESTION:

I seem to have an increasingly "healthy" supply of Equisetum in ALL of my many gardens over the years .. it is not easy to get all the rhizomes (what is?) is it possible to control it some other way? Could pH have something to do with it?

ANSWER:

There are 10 species of the genus Equisetum native to New Hampshire; we have chosen Equisetum hyemale (scouringrush horsetail) as a representative species to use as an example.  It and the rest of the  Equisetum  genus are very much wetland plants-they tolerate shade, poor drainage, occur in wet places and even standing in water. They are considered very aggressive, which you have already found out. 

We felt your question about the pH having something to do with the too-healthy growth of the horsetails was thought-provoking, but we could find no research to support that one way or the other. What we did learn was that it did best in marshy, poor drainage soils, and even standing in water. We don't know what kind of garden you have; if you have a water garden, and started the Equisetum in that water garden without confining it in pots without holes, that is no doubt the source of your problem. If it is growing in your soil, the soil must be very poorly drained, and we are wondering what other plants you have been able to grow there. 

Everyone wants a special spray that will just kill the one plant they are interested in eliminating. The Lady Bird Johnson Wildflower Center recommends neither for nor against the use of herbicides. We found two articles that dealt with elimination of this plant. The first is from University of Minnesota Extension Horsetail by Beth Jarvis.  Here is an excerpt from that article:

"Horsetails are difficult to eradicate without the use of herbicides. They favor damp, sandy or gravelly, shady places. Depending on where they're growing, improving drainage and fertility and increasing the organic material in the soil along with regular mowing or clean cultivation may make the site less hospitable. Digging the plants out, in all but the smallest sites, could be prohibitively difficult due to the depth and spread of the underground rhizomes."

Another article, from a UK newsgroup, has more herbicide information to add: Re: Horsetail Roots.

Our conclusion from all of this is that you may need to modify the environment in which your garden is growing. In other words, improved drainage, drier, richer, maybe with taller plants to shade out the Equisetum. Cut off the spore-bearing cones before they ripen and spread more spores, but with all those rhizomes under ground, it will be difficult to starve out the plant. 


Equisetum hyemale var. affine

Equisetum hyemale var. affine

Equisetum hyemale var. affine

Equisetum hyemale var. affine

 

 


 

More Invasive Plants Questions

Dog-proof grass from The Woodlands TX
April 26, 2013 - I am looking for a hardy grass that can tolerate female dogs urine. Zoysia was suggested but I am concerned about it being invasive. Any suggestions?
view the full question and answer

What is wrong with cultivars of native plants?
May 26, 2009 - What is wrong with cultivars of native plants? My state native plant society won't allow cultivars at their annual sale, and the native plant nursery from which I order only offers the species. But a...
view the full question and answer

Invasive native mint in Tippecanoe OH
August 23, 2009 - I have a problem with Mentha Arvensis, I raise sheep and goats and they will not eat this. The mint is starting to take over my 65 acre farm,Q.What is best way to rid this plant so I do not lose my gr...
view the full question and answer

Ground cover for Central California from Concord CA
July 19, 2012 - I live in a part of California where the summers can be very hot and dry but quite cool and wet during the rainy seasons in the wintertime. The soil around my home is very dry, rocky and infertile. I...
view the full question and answer

Japanese Wineberry in Maryland
July 16, 2014 - Hello, we were at Cunningham Falls in Maryland and I can not identify this plant. If you could I would greatly appreciate it, thank you. It looks like a raspberry but the berries are inside small leav...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center