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?


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

Wednesday - December 10, 2008

From: Dallas, TX
Region: Southwest
Topic: Shade Tolerant
Title: Grass to grow in the shade of pecan tree
Answered by: Nan Hampton


Dear Mr. Smarty Pants, We have an enormous pecan tree in our backyard that had grass underneath the breadth of the branches, but not around the trunk. The grass isn't doing well (though we did fail to fertilize it last year) and I was wondering if there is a grass that can grow under the shady limbs of a pecan tree. Will the shade and juglones kill anything and everything off? Thanks so much!


You are correct that the juglones that are produced by trees in the Family Juglandaceae (Walnut Family) are allelopathic to some, but not all, other plants. You can see lists of plants susceptible to juglones and those tolerant of juglones from Ohio State Univeristy.  It appears that the level of  juglone in Carya illinoinensis (pecan) is less than in walnuts.  Grasses, in general, seem to be tolerant of juglones.  In fact, there have been studies showing that bermudagrass and tall fescue are allelopathic to pecan seedlings!

Here are three grasses and a sedge that occur in the Dallas area and will grow in the shade.  I have personal experience with inland sea oats growing quite happily under my walnut tree and suspect the other three species will also be tolerant of your pecan's juglones.

Chasmanthium latifolium (Inland sea oats)

Elymus canadensis (Canada wildrye)

Muhlenbergia schreberi (nimblewill)

Carex blanda (eastern woodland sedge)

Chasmanthium latifolium

Elymus canadensis

Muhlenbergia schreberi

Carex blanda





More Shade Tolerant Questions

Grasses for shade in McKinney TX
August 19, 2010 - Dear Sir, We have lived in the same house for 25 years and when we originally moved in we had St. Augustine sod installed and for several years it did very well until my trees started getting bigge...
view the full question and answer

Deer resistant plants for Pittsburgh PA
January 30, 2012 - What shrubs can I plant on a wet slope that gets partial sun that will help control erosion? They need to be something the deer won't eat! We have lots of deer.
view the full question and answer

Small evergreen shrubs for part shade in Texas
January 31, 2015 - Mr. Smarty Pants, I'm, for some reason, at odds with myself about a shrub decision. I have need about 8 ft of hedge-like evergreen shrub(s) that I can maintain around 4ft to go under a window. It...
view the full question and answer

Sedges and ornamentals for shade in Bastrop County
June 20, 2007 - I bought a home in Elgin, TX that was owned by an elderly woman. Most of the lawn is shaded by elm or pecan trees. In the sunny areas, i got native wildflowers to grow like lantana and coneflower,...
view the full question and answer

Native vine for shade on west side in Texas
July 21, 2008 - I have just put in a trellis to cover the west side of my house for shade. What would be the best native vine to put their for quick growth. I plan on putting a rose (Fortunia) but can't do that till...
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.
© 2015 Lady Bird Johnson Wildflower Center