En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Removal of invasive horsetail in Shelby Township, MI

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

Friday - June 19, 2009

From: Shelby Twp, MI
Region: Midwest
Topic: Invasive Plants, Compost and Mulch, Trees
Title: Removal of invasive horsetail in Shelby Township, MI
Answered by: Barbara Medford

QUESTION:

Please help me or direct me to who may be able to help. I have horsetail (Equisetum) invading my Blue Rug Juniper. Please tell me what I can use to get rid of the horsetail (Equisetum) without killing off the Blue Rug Juniper. Thank you so much for your time and effort.

ANSWER:

There are 11 species of the genus Equisetum native to Michigan; we have chosen Equisetum hyemale (scouringrush horsetail) as a representative species to use as an example. Blue Rug juniper is the cultivar 'Wiltonii' of Juniperus horizontalis (creeping juniper), also native to Michigan.  So, we can understand your having both plants in your garden, as both are native; what we can't understand is why they are growing close enough together to be interacting. Equisetum hyemale (scouringrush horsetail) (and the rest of the 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. Juniperus horizontalis (creeping juniper) is intolerant of shade and poor drainage, needs dry soil and does best on dry, sunny hillsides.  If the Equisetum is competing successfully with the juniper, then it's obvious the juniper is in the wrong place.

What to do? The first and most obvious solution would seem to be move the juniper, if that is at all feasible. If it is too large to move or there is no other more suitable spot in your garden, you will need to amend the soil, and perhaps prune back trees to provide more sunlight. Either way, you are going to have the get the horsetail out of the juniper, and the only way to do that is by pulling it out, and keep on pulling it out. It spreads by rhizomes, shallow underground roots. Most plants that spread that way are happy to snap off at the ground when you pull them, because those underground rhizomes are down there with food stored up ready to resprout the plant. 

To amend the soil for the juniper, you must improve the drainage. The best way to do this (without digging them up and getting them into a raised bed) is to work compost or some other organic material into the soil and continue to do so periodically. Also, mulch the soil, without covering the crowns of the juniper, with a good quality shredded hardwood bark mulch. This could help suppress the horsetail, although it's unlikely. The main benefit of the mulch is that it will protect the roots of the juniper from heat and cold, and as it decomposes it will continue to add to the organic content of the soil and improve drainage. 

Pictures of Blue Rug juniper


Equisetum hyemale

Equisetum arvense

Equisetum hyemale var. affine

Equisetum laevigatum

 

 

 

More Invasive Plants Questions

Invasiveness of Cosmos from Decatur GA
April 26, 2013 - I have been searching for an answer concerning the invasive plant Cosmos. I know that Florida declares this but I have not been able to find out does Georgia? And specifically,is it only the yellow Co...
view the full question and answer

Shade tolerant plants for privacy from Larchmont NY
April 19, 2014 - Love your site! We have a 4'x4'x50' stone wall, full sun, with a planting bed 30"H by 24"D. We're looking for privacy, so a hedge with pruning is needed. We have looked at Ilex Crenata (8'),...
view the full question and answer

How do I get rid of Smilax bona-nox?
June 09, 2009 - Hi, we live in Circle C and our home backs to an easment area which has become overrun with what some are calling wild grapevine. Recently we noticed a different vine coming up in our backyard throug...
view the full question and answer

Pictures of Bastard Cabbage from Dallas TX
April 07, 2012 - HI! Re your March 12 posting: The USDA Plants website pictures two very different looking plants identified as Rapistrum rugosum (bastardcabbage). Would you please post a photo with leaf and bloom ...
view the full question and answer

Controlling Phragmites australis, common reed
July 04, 2008 - Dear Mr. Smarty Plants, I volunteer at Cedar Ridge Preserve in Dallas. We are currently chopping down an invasive called Phragmites australis around the pond. The belief is that by continuously cho...
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