En EspaÑol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

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
2 ratings

Monday - May 10, 2010

From: Franklin Lakes, NJ
Region: Northeast
Topic: Invasive Plants, Problem Plants
Title: Eliminating dogbane from transplanted milkweed in Franklin Lakes NJ
Answered by: Barbara Medford

QUESTION:

We transplanted milkweed from the wild into our garden. Included in the clump of milkweed was dogbane. We weren't aware of how invasive dogbane is. We've has some success in digging it out but we're losing the battle! Do you have any suggestions to help us eliminate our dogbane problem?

ANSWER:

Apocynum cannabinum (Indianhemp), also known as "dogbane" is native not only to Bergen Co., but just about the whole state of New Jersey, as seen in this USDA Plant Profile.  So, you're not alone if that is any comfort. A number of varieties occur across the continent. This species can become a serious weed as it is aggressive and difficult to control. It is also a dangerous plant to have in your garden. From our page on this plant in the Native Plant Database: "POISONOUS PARTS: All parts, fresh or dry. Highly Toxic, May be Fatal if eaten. Symptom: Cardiac arrest. Toxic Principle: Resins and cardiac glycosides."

So, getting rid of it is a good goal. It is perennial, so just preventing it seeding out is not going to be enough, but it's a start. This plant is starting to bloom now-do whatever you can to keep those blooms from becoming seeds. Pull the whole plant out if you can, or keep trimming it as low as possible to keep it from re-blooming.  The problem with just pulling it out, of course, is that you are probably also be pulling out some of your milkweed, and spraying it with herbicide will have the same effect, killing the milkweed just as surely as the dogbane. These plants may be found growing as colonies due to a long horizontal rootstock that develops from an initial taproot

So, you have a multi-pronged problem; you must not only prevent it from re-seeding but also get out the root from which new plants can grow, as well. From this site, primitiveways.com, Dogbane, we learned that the milkweed you brought the dogbane in with is likely Asclepias syriaca (common milkweed), and extracted this information:

"Stems and leaves secrete a milky sap when broken. Sprouts emerging from the underground horizontal rootstock may be confused with Common Milkweed (Asclepias syriaca) emerging shoots. But note that they are not related to milkweeds, despite the milky sap and the similar leaf shape and growth habit. The flower shape is quite unlike that of milkweed flowers and the leaves of hemp dogbane are much smaller than those of common milkweed. When mature, these native plants may be distinguished by the branching in the upper portions of the plant that occurs in hemp dogbane, and also the smaller size of hemp dogbane compared to Common milkweed."

We noted that the common milkweed is native to exactly the same areas as the dogbane, so it's no wonder they got mixed up.  You will have to be careful not to put herbicide on the milkweed, or leave the dogbane roots behind, thinking they are milkweed.

From our Native Plant Image Gallery:


Apocynum cannabinum

Apocynum cannabinum

Apocynum cannabinum

Apocynum cannabinum

Asclepias syriaca

Asclepias syriaca

Asclepias syriaca

Asclepias syriaca

 

 

 

More Problem Plants Questions

Controlling sandburs from Austin
February 24, 2013 - Hello, What is the best way to prevent sticker burrs from growing in a rocky bed with no grass. There are many other plants we want to preserve and a drip line to keep them watered. We have 2 small k...
view the full question and answer

Methods of controlling poison ivy
April 19, 2005 - What do you suggest for controlling poison oak (ivy)?
view the full question and answer

Black Walnut tree in LA
March 12, 2012 - I was just given a black walnut tree and am trying to determine where to place it. I’ve read on your site that “Certain plants will not grow under Black Walnut trees because of the juglones that the ...
view the full question and answer

Killing oak sprouts from El Paso TX
August 16, 2011 - I want to know how to kill oak root sprouts and seedlings. Very dense and out-of-control in huge area of front lawn. I had tree cut down and I still cannot get rid of them. They're only getting wors...
view the full question and answer

Cat eating yucca stalks in England
May 07, 2013 - Is it safe for my cat to eat yucca as she is being sick and its hard to stop her
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