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

Friday - December 09, 2005

From: Auburn, IN
Region: Midwest
Topic: Trees
Title: Determining distance of trees from paving in NE Indiana
Answered by: Nan Hampton and Joe Marcus

QUESTION:

I'd like to plant 3 types of trees (Catalpa speciosa- Northern Catalpa; Juglans cinerea - Tulip Tree; and Acer saccharum - Sugar Maple) next to sidewalks and driveways, but need to know if they have roots deep enough to not break up the concrete/asphalt. I live in NE Indiana. Thank you.

ANSWER:

Although trees are generally divided into two groups by root type—tap root trees (such as oaks, hickory, walnut, conifers) and lateral, or fibrous, root trees (maples, ash, cottonwood)—this distinction is most evident as seedlings or saplings. Once the tree is planted and begins to mature, the distinctions between the root types become less pronounced. Then, the depth and lateralness of the roots is greatly dependent on the soil condition. Highly compacted soils, soils with low oxygen content and soils where the water table is near the surface are not likely to produce a strong tap root. Their roots are more likely to be lateral and located very near the surface with the majority of the roots located in the top 12 inches of soil. Also, it is important to realize that the spread of the roots can be at least 2 to 4 times greater than the drip line of the branches.

Sidewalks and Trees from Iowa State University Extension Service recommends basing the distance trees are planted near pavement on the mature height of the tree. Their recommendations are:

1. trees with a mature height of less than 30 feet, 3-4 feet from pavement,
2. trees with a mature height of 30 to 50 feet, 5-6 feet from pavement,
3. trees with a mature height of greater than 50 feet, at least 8 feet from pavement.

They also recommend installing root barriers underground between the tree and the sidewalk. Another recommendation from Iowa State is to avoid planting shallow-rooted trees near sidewalks. Unfortunately, the sugar maple (Acer saccharum) is on their shallow-rooted tree list. I am not sure whether you mean to plant the tulip tree, which is Liriodendron tulipifera, or the butternut, which is Juglans cinerea. If it is Liriodendron tulipifera, then that is also on the shallow-rooted tree iist. The butternut, Juglans cinerea, is not on the list, nor is the northern catalpa (Catalpa speciosa). You can read a list of recommended Trees for Parking Lots and Paved Areas from Virginia Cooperative Extension. Be aware that not all the trees on the list are native. The Lady Bird Johnson Wildflower Center recommends that you plant native trees. You can also read more about Tree Roots from Iowa State University Forestry Service.
 

More Trees Questions

Disagreement with HOA on raised beds placed beneath mature oak from Tequesta FL
April 05, 2014 - I have mature 30 year old oak trees on my property and I put a raised bed under each with very good soil and I used pavers for retaining the soil about about 1.5 ft high. I planted a perennial begonia...
view the full question and answer

Live Christmas tree in Katy, TX
March 16, 2010 - My husband is really bent towards having a live "Christmas tree" in the front yard. I hate to use anything non-native so I am looking for a native Texas juniper shrub or a small tree that can be tri...
view the full question and answer

Screening Suggestions in Brooklyn, NY
March 08, 2013 - My neighbor directly in back of me has shrubs that are growing all over my fence. Also his 9-foot-tall shed facing me is rusted. What can I do to improve my view so that I can enjoy my backyard more?
view the full question and answer

Defining drip line on trees from Austin
August 08, 2011 - When you say that trees should be watered at the "drip line," do you mean that literally? I assume that the drip line means at the outside edge of the leaves or branches. Does that mean that waterin...
view the full question and answer

Need help with a fungal disease in oak trees in Austin, TX
April 26, 2012 - Two adjacent oak trees in my yard are showing distinct symptoms of Sudden Oak Death. Most notably, the lowest ten feet of their trunks have several bleeding cankers with thick, tarry ooze and no accom...
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
© 2014 Lady Bird Johnson Wildflower Center