Host an Event Volunteer Join Tickets

Support the plant database you love!

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

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

Saturday - January 30, 2010

From: Clover, SC
Region: Southeast
Topic: Trees
Title: What plants to put under an oak tree in Clover SC
Answered by: Barbara Medford

QUESTION:

I have a 70 year old oak tree in my backyard and have tried to grow grass out from it with no success. I'd like to just plant some shrubs and make it a natural area now, but need advice on what I can plant near the oak, not directly under it. The area where I want to create a garden is about 10-12 feet from the oak. I've planted flowers away from the oak in the past, but nothing has done well. Any suggestions on shrubs or flowers that I would do well about 10 ft away from the oak? Also, would it be better to create a large raised bed and create a garden area that way?

ANSWER:

An oak tree that old is a valuable landscape asset, so your first question should probably be: "What will not harm the tree?" Oak trees do not like competition. Their heavy shade in summer, and the year-round presence of the root system are disadvantages for plants beneath the oak. Furthermore, the mature oak is known to have the quality of allelopathy, which means they emit substances that will inhibit the growth of plants beneath them; these substances can come from roots, twigs, or leaves. You say you plan to plant 10 to 12 feet from the oak, we assume that is from the trunk. A tree that old likely has a pretty impressive canopy, and the roots can extend out up to three times the circumference of that canopy.

Next, your idea of making a raised bed would possibly permit you to grow some plants, but it would not be good for the oak. These far-reaching roots we described reside mostly in the upper 12 inches of the soil. That characteristic is to ensure the roots have easy access to moisture, nutrients and oxygen. Piling soil up on those roots might not damage the tree right away, but in the long run it could begin a die-back of the most affected areas, eventually becoming an unattractive liability. If you dig holes for shrubs in the ground level, without raising the bed, you will both be destroying roots of the tree and putting roots of the shrubs in competition with the roots of the tree, whch is advantageous to neither.

We don't like to sound so negative, but we also would hate for you to waste time and resources putting in plants that will not thrive and possibly damaging your tree, as well, in the process. One possibility might be to put down a good quality shredded bark mulch beneath the tree, and perhaps ring that mulch with shrub beds having the same mulch in them. They would blend together nicely and look natural. With that in mind, we are going to recommend some shrubs native to South Carolina that will tolerate sun or part shade. We tried to choose some that are considered "understory" plants; i.e., they should do pretty well at coping with interference from trees. Follow each link to the page on that plant to learn other characteristics and growing conditions. 

Shade or Part Sun Shrubs for Cover SC:

Callicarpa americana (American beautyberry) - 3 to 5 ft. tall, deciduous, blooms white, pink May to July, part shade

Comptonia peregrina (sweet fern) - 2 to 4 ft., blooms white, green May to August, part shade

Hydrangea arborescens (wild hydrangea) - 3 to 6 ft., deciduous, blooms white, green June to August, part shade

Hypericum prolificum (shrubby St. Johnswort) - to 3 ft., deciduous, blooms yellow June to August, part shade or shade

Symphoricarpos orbiculatus (coralberry) - 4 ft., deciduous, blooms white, green April to July, part shade or shade

From our Native Plant Image Gallery:


Callicarpa americana

Comptonia peregrina

Hydrangea arborescens

Hypericum prolificum

Symphoricarpos orbiculatus

 

 

 

More Trees Questions

Mexican Plum with wilted leaves in Austin, TX.
June 06, 2012 - I am new to Texas & have a yard with mature mexican plum trees. They are quite beautiful however as summer sets in I notice that the leaves appear "wilted". Is this normal or should I be providing...
view the full question and answer

Large tree and smaller specimen tree for Austin, Texas
May 01, 2007 - We are in the process of removing two Silver Maples in our front yard planted by the previous owner of our house. We live close to the Wildflower Center and have very shallow soil on top of rock. We...
view the full question and answer

Dying branches on Texas Mountain Laurel from Kempner TX
September 14, 2012 - The branches on my Texas Mountain Laurel are very dry and brittle. The leaves are also starting to die. The tree has been in my yard for six years and prior to that it sat wrapped in burlap for ov...
view the full question and answer

Care of lemon cypress (Cupressus macrocarpa)
May 17, 2008 - How do I grow the lemon cypress in zone 7? I bought one today at Home Depot in Granbury,TX. It had no information. Should I put it in the shade or sun?
view the full question and answer

Escarpment Black Cherry losing leaves in Austin, TX.
July 13, 2012 - Dear Mr. Plants: We live in Austin off of Mount Bonnell Road. We have beautiful 20 foot tall + black escarpment cherry tree very near the house with leaves turning yellow like it's about to drop th...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.