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
Not Yet Rated

Friday - July 08, 2011

From: Vista, CA
Region: California
Topic: Poisonous Plants, Trees
Title: Are palm tree seeds toxic?
Answered by: Nan Hampton

QUESTION:

Are palm tree seeds toxic to other plants? I have palm trees around my pool and it seems that nothing will grow very good where the old seeds are in the ground.

ANSWER:

I'm not sure what palms you have.  The only palm native to California is Washingtonia filifera (California fan palm), but there are other palms commonly found there [e.g., Phoenix canariensis (Canary Island Palm) from the Canary Islands, Phoenix dactylifera (Date palm) from Asia and Washingtonia robusta (Mexican palm fan)].

I searched for references to palms and allelopathy and below are the only references I found. 

M. I. Khan in an article, [Allelopathic potential of dry fruits of Washingtonia filifera: Inhibition of seed germination.  Physiologia Plantarum, 54(3):323-328, 1982] says that the leachates of the fruits of this palm inhibited the germination of the seeds of lettuce and cucumbers.

Another article by Khan [Allelopathic potential of dry fruits of Washingtonia filifera (L. LINDEN) H. WENDL.  II.  Inhibition of seedling growth.  Biologia Plantarum, 24(4), 1982] reports the allelopathic effect of the dry palm fruits on growth of the seedlings of lettuce, red cabbage, tomato and cucumber.

Finally, A. K. Mukherjee [Allelopathy in Phoenix paludosa pure stand formation.  Journal of Economic and Taxonomic Botany, 12(2), 1988] reported that the roots of Pheonix paludosa (Mangrove date palm), an Asian species related to date palms found in California, delayed germination and retarded the growth of gram (a kind of bean) seed.   Mukherjee speculates that a growth retardant from the roots of the palm eliminates competing plants and results in pure stands of the palm in India.

These references are to experiments performed 20 years or more ago and no one has repeated them, as far as I know, nor has anyone reported allelopathy associated with any other palm trees.  That doesn't mean that your palm seeds or fruits don't have any allelopathic properties.  Since palms are prevalent in lots or landscapes, however, it seems that it would be reported by homeowners and landscapers.  

Just in case the seeds or any other parts of the above ground tree is inhibiting the growth of plants underneath your palm, you can alleviate the effect by keeping the area under and around the tree free of fruits, seeds and fronds.  Also, since the palm is going to provide a good deal of shade, this could be part of your problem.  Try choosing shade-loving plants for the area under the palms. 

 

More Trees Questions

Tree with tap root for small area near Dallas
September 07, 2009 - Mr. Smarty Plants, I live in Coppell, TX (a suburb of Dallas) & am looking for a tree to plant near our pool to provide some shade. The current tree (a silver leaf maple) is dying. My husband thi...
view the full question and answer

Taproot tree to replace willows by pool
June 23, 2008 - Installing Pool with bomanite decking all around it. We're in process of cutting down 18 year old Weeping Willow due to root invasiveness and small messy leaves. Can you recommend a good shade tree w...
view the full question and answer

More trees to go with live oaks in Schertz TX
July 13, 2010 - We moved to a new house that has two recently planted live oak trees. Other than those two little trees there is nothing else on the property. Because of what I read about the oak wilt I would like ...
view the full question and answer

Is Texas Mountain Laurel Honey Toxic in Fulshear, TX?
March 11, 2012 - Toxicity of Texas Mountain Laurel HONEY I know the seeds and leaves of the Tx Mountain Laurel are toxic. But, is honey that comes from the Mountain Laurel toxic too? I heard that it is, but can'...
view the full question and answer

Incorrectly planted anacua from San Antonio
November 22, 2013 - I purchased a 12' anacua tree from a local nursery about 18 months ago. It was not planted correctly (root bound, rolled into a hole about 3" larger than the pot) but is still alive with the number...
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