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

Evergreen for privacy in PA
July 18, 2011 - We need to plant a privacy/sound barrier hedge/hedgerow and my husband says it must be evergreen. I am not familiar with which species would be native to our area and I just don't trust those big sto...
view the full question and answer

White pine insect problems
October 08, 2009 - We live in The Woodlands TX. Some of our large pine trees have leaking sap and one is dead. What can we do to save the one's still alive?
view the full question and answer

Do Maple trees and Poplars grow well in Amarillo,TX?
May 25, 2010 - Do maple trees and poplars grow well in Amarillo Texas? I love the fall reds, oranges, and yellows. If they don't grow well can you recommend some trees that have the color that will grow well?
view the full question and answer

Location of pine trees for a wedding site in Grapevine TX
April 30, 2014 - Okay, I know this is a long shot. My daughter is getting married in Grapevine, October 18 at sunrise. She REALLY wants to have the ceremony near pine trees. Any suggestions for locations in Grapevine ...
view the full question and answer

Need suggestions for a replacement tree for Hackberry tree in Austin, TX in Austin TX.
May 25, 2013 - We have a large hackberry tree in our front yard. We are cutting it down this fall. I would like to replace it with a tree native to this area..preferably something fast growing. What are your reco...
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