En EspaŅol

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

Can fibrous roots of Chasmanthium latifolium damage house foundation
May 03, 2013 - Dear Mr.Ms. S-P, Can the fibrous roots of inland sea oats cause foundation problems? I was digging around my foundation and found a root about 1" in diameter that I am afraid might be from sea oa...
view the full question and answer

Skin Reaction form Cochineal on Prickly Pear
February 16, 2015 - I have severe burning and peeling skin on pads of fingers after touching "white stuff" on a prickly pear. White stuff tuned purple then burned skin even after washing hands. Skin has been cracking a...
view the full question and answer

Plant identification of vine in Ohio
September 21, 2010 - I have a vine in my forest that grows up trees, that could eventually pull them over. It has roundleaves and prickers on the stem. What is this vine so I can research it?
view the full question and answer

Controlling sedge in vegetable garden in Mississippi
August 03, 2008 - I have a veg. garden surrounded by Purple Sedge. The nut grass has been contained/eliminated by replacing all dirt 1' down. Now the surrounding sedge is beginning to creep inward infesting the gard...
view the full question and answer

Controlling Passionflora Incarnata propagation
March 20, 2012 - Would a cinderblock raised bed, 8 inches in height, be sufficient to contain the roots of passiflora incarnata and keep them from traveling to places where I don't want the vine? Are the roots deepe...
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center