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
1 rating

Monday - October 04, 2010

From: Wimberley, TX
Region: Select Region
Topic: Best of Smarty, Soils
Title: Growing Native Plants in Juniper litter from Wimberley, TX
Answered by: Mike Tomme

QUESTION:

Junipers create an environment under their canopy that prohibits growth of other plants. I have a virgin lot that has been cleared of many juniper but has remaining heavy natural leaf mold containing juniper leaf fall. Will this old dense leaf mold prohibit the growth of newly-planted natives in areas that were heavily populated with junipers? It contains a lot of Spanish oak leaves, as well.

ANSWER:

Mr. Smarty Plants has talked about your concerns in a previous answer. Part of that answer is worth repeating here because the belief that "cedar trees" which is what we here in central Texas call Juniperus ashei (Ashe juniper) somehow "poison" the soil is so widely held (see the Mark Twain quote at the end). Here's a quote from the article  Biology and Ecology of Ashe Juniper by F. E. Smeins and S.D. Fuhlendorf:

"There is little evidence that the accumulated litter of Ashe juniper in anyway alters the chemical nature of the soil as it relates to growth and development of other plants (Yager 1993). Soil chemical and physical properties are in fact "improved" by the presence of the juniper litter (Marshall 1995). No allelopathic effects have been shown to be produced by the litter. The major impact of the litter seems to be its physical presence and its alteration of hydrologic properties of the area under the canopy. The thick litter layer is a difficult physical medium for seeds of other species to germinate and grow in mainly because moisture either runs off (due to the hydrophobic nature of the litter) or it dries out very quickly after a precipitation event, which prevents seedling growth from reaching the mineral soil (Yager 1993)."

The wording of your question indicates you understand a very important point when you say, "Junipers create an environment under their canopy." They do indeed. That environment includes dense shade and a lot of shed material like leaves, berries and bark (aka mulch).  Add to this that the shed material is hydrophobic ( it sheds water rather than absorbs it) and I ask you what could be less conducive to existing plants or new seedlings?"

To sum up, Mr. Smarty Plants says don't worry about what grew there before. You need to till the litter from the junipers and oaks into the soil and plant natives appropriate for you area, soil, light, drainage and enjoy.

It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so. - Mark Twain.

 

More Soils Questions

Foundation Plants for South Carolina
November 07, 2009 - What native plants are suitable as foundation plantings? My soil is heavy clayey loam with red clay subsoil. I live in Charleston County.
view the full question and answer

Plants adding calcium to soil
June 08, 2006 - Hi, I am looking for a resource to help determine the functions of native plants. For instance, nitrogen fixing can be found in Indigo, Lead plant, lupines. Are there other plants that add back cal...
view the full question and answer

Will wood shavings in the soil require nitrogen from Charleston MO
May 04, 2011 - I cut down a big maple tree and a lot of the wood shavings was left in the soil. I planted a flower bed over the area this spring. I later read that the wood chips in the soil would use a lot of nitro...
view the full question and answer

Malpighia glabra for Austin
October 14, 2010 - Dear Mr. Smarty Pants, I am planting native Malpighia in a raised bed that was specially prepared for growing roses (soil and amendments). This bed has been left fallow for several years. Do I need t...
view the full question and answer

User comments on soils from Austin
July 02, 2013 - You had a question this month about chlorosis in a Mexican plum in Bellaire. You correctly, in my opinion, answered that the problem was most likely overwatering. However, I just wanted to point out a...
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