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?


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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

rate this answer
Not Yet Rated

Wednesday - December 03, 2008

From: San Antonio, TX
Region: Southwest
Topic: Shade Tolerant
Title: Understory shrub for shady area in San Antonio
Answered by: Barbara Medford


We would like to plant a small understory tree/shrub in an odd space that our new deck has created between our fence line and the house. A mature mountain laurel would be our dream but I think there is too much shade. Also since this would probably overhang the deck at some point, it might be kind of messy. Our next door neighbors' large red oaks branches extend over the fence and over our deck. This tree would be under their "umbrella". We would like this tree to reach about 10-12' high. What would you suggest?


We'd like to start this by discussing that red oak hanging over the fence. There are a number of oaks referred to by the common name "red" oak, but we're assuming you probably have Texas native Quercus shumardii (Shumard's oak) in your neighbors' yard. Shumard's Oak dislikes the competition of understory plants, and, at maturity, will retard the growth of competing understory vegetation, apparently by allelopathic effects. Allelopathy involves the emitting of chemicals produced by the tree that will damage the growth of plant materials beneath it. Most oaks have this ability to some degree, with the Shumard's Oak being moderate in this respect. This, along with the shade involved, is the main reason it is difficult to grow grass or flowering plants beneath an oak. So, before you put a great deal of effort into planting a shrub there, you might consider that possibility. If your neighbor would be willing to do so, and certainly you have the right to ask that it be done, trimming of the tree overhang might help both with the shade and the allelopathy issues.

Now, on to the possibilities for this space.  You are correct that the Sophora secundiflora (Texas mountain-laurel) ordinarily needs more sun than it sounds like you have, and that all those flowers, followed by seeds, can make quite a mess. Moreover, the seeds, which grow in long pods, are bright red, attractive and very poisonous. Two of our other suggestions also have poisonous parts; you might consider the safety of having that kind of plant in an area where families and pets might gather. Follow the plant links to a complete webpage on each plant to learn other details of its growth and bloom. At the bottom of that page you will find a link to Google for more information on that plant.


Ilex vomitoria (yaupon) - 12 to 25' high, bright red berries on female plants

Rhus virens (evergreen sumac) - 8 to 12' tall


Amorpha fruticosa (desert false indigo) - 6 to 10'

Ilex decidua (possumhaw) -15 to 20' tall, clusters of persistent winter berries on female plants

Bauhinia lunarioides (Texasplume) - 6 to 12', fast-growing

Cercis canadensis var. texensis (Texas redbud) - 10 to 20'

Diospyros texana (Texas persimmon) - 12 to 36'

Prunus mexicana (Mexican plum) 15 to 35', like all members of Prunus genus has poisonous seeds

Ungnadia speciosa (Mexican buckeye) - 8 to 12', seeds poisonous

Sophora secundiflora

Ilex vomitoria

Rhus virens

Amorpha fruticosa

Ilex decidua

Bauhinia lunarioides

Cercis canadensis var. texensis

Diospyros texana

Prunus mexicana

Ungnadia speciosa



More Shade Tolerant Questions

Small, drought and shade-tolerant perennials for Austin, Texas
March 22, 2010 - We need suggestions for small, drought- and shade-tolerant perennials to be planted in Austin, Texas, please.
view the full question and answer

Native plants with little sun and northern exposure for New York
April 26, 2006 - I live in a co-op and want to fix up the backyard. The backyard area has a west area to plant with a northern exposure and little sun and I am looking to plant something to cover the area. I would lik...
view the full question and answer

Evergreen shrub for part shade in Austin
September 21, 2010 - I am planning a pocket prairie on the north side of my house. Where I am struggling is finding an evergreen shrub that will grow about 6-8', be native and provide semi-privacy in front of a bedroom ...
view the full question and answer

Native ground cover for part shade in Dowagiac MI
June 24, 2009 - Maybe I'm just too picky. I'm trying to make an area that is some what triangular shaped between my house and garage with a tall lattice/privacy fence on one side and walks in the back yard area on...
view the full question and answer

Evergreens for privacy in VA
June 24, 2012 - I need fast growing evergreens or large shrubs, flowering or non-flowering, for privacy. They will need to flourish among large oak and hickory trees that are 75 plus years old. We don't want to dama...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center