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

Monday - June 03, 2013

From: Austin, TX
Region: Southwest
Topic: Soils
Title: Asphalt beneath surface of soil in Austin
Answered by: Barbara Medford

QUESTION:

About 3-4 inches below the surface of our yard is what appears to be asphalt. It comes out in chunks a few inches across and it's all about 1.5 inches thick. I have no idea what it is; my best guess is that our lot was at one time a parking lot or something before it was developed into a subdivision. Other than just being a pain every time I have to dig a hole, will this cause any problems for my plants by leaching chemicals into the ground or anything like that?

ANSWER:

This is not a happy situation and we were unable to find any actual scientific studies on the question, but we did find a couple of forums. You need to remember that forums are the expression of opinions on the part of whoever writes in, and not necessarily scientific fact. However, here are links to those forums:

Garden Web

Fine Gardening

Our opinion is that it was illegal to leave this material in the soil, and should have been caught in inspections of the property, but we are gardeners, not lawyers. You might try contacting the Texas A&M Agrilife Extension Office for Tarrant County to see if they have any information. As gardeners, we would not want to plant anything, especially anything edible, in that soil and consider it contaminated.

 

More Soils Questions

Improperly prepared building site in Virginia
June 24, 2008 - Hi, I have a question about planting on newly-built homesite. We just moved into a new home in DC suburbs (Northern VA) and the landscape is the worst of the builder grade. There are prickly junipers ...
view the full question and answer

Plants to grow in high zinc, lead and copper soil in Los Angeles
January 24, 2011 - We live on the Westside of Los Angeles and have just been given the bad news that our beds are high in zinc (86.39), lead (45.98) and copper(12.95). Can you recommend some plants that may grow in thes...
view the full question and answer

Gregg's Mistflower stressed in Fredericksburg TX
August 07, 2013 - My Gregg's Mist Flower plants are very stressed. The blooms have turned brown and the leaves are drooping. Plants are receiving moderate sun, partial shade. Do they need daily watering this time o...
view the full question and answer

Use of fresh clippings from tree trimmers for mulch in Austin
May 02, 2010 - Hi, The tree trimmers are in my neighborhood (east central Austin) to clear the power lines and said I can have a load of free mulch. I am wondering if there is any harm in using the fresh mulch from...
view the full question and answer

Replacing hawthorn bush with muhly grass from Plano TX
April 10, 2014 - I am thinking of replacing a hawthorn bush with a muhly grass plant or two in an edged area with river rock cover in Plano, texas. It is the black soil and not a sandy loam. We have a sprinkler syst...
view the full question and answer

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