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
2 ratings

Monday - August 08, 2011

From: Austin, TX
Region: Southwest
Topic: Watering, Trees
Title: Defining drip line on trees from Austin
Answered by: Barbara Medford


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 watering closer to the trunk won't help the tree, even if the grass or plants underneath do benefit?


Sorry, we get so used to using certain catch words, we forget that not everyone speaks the same language. Watering anywhere around a tree during the kind of weather we are having is beneficial. When a tree is small and new, we recommend sticking the hose in the soil around the base and letting it drip slowly until water comes to the surface, at least twice a week. With a mature tree, not only would it be difficult to get that hose in there with all the roots, but there are roots extending far beyond that which need the moisture, too. Using the phrase "drip line" is just a quickie indicator, and not totally accurate. Remember that the roots of a large tree will often extend out a distance at least comparable to the height of the tree, which is usually much farther out than where the edge of the shade from the tree, or drip line, is established. Yes, run the sprinkler under the tree and not under the tree but still over the roots. The only caution we would make is to avoid getting the bark of the tree too wet, as this can invite fungi and diseases.


More Trees Questions

Hurricane resistant alternatives to crape myrtle
September 02, 2007 - Are there any native small to medium trees (15-25 ft) to use instead of crapemyrtles (Lagerstroemia indica)? Crapemyrtles come in many colors and bend with hurricane winds instead of snapping or uproo...
view the full question and answer

Failure to thrive of pecan trees in Las Vegas NV
October 11, 2009 - In April this year I purchased two 8-foot tall pecan trees in 3-foot square boxes from a local nursery and planted them here in Southern Nevada. I'm sure I dug a large enough hole to provide plenty ...
view the full question and answer

Cypress trees near pool in Winter Park FL
August 17, 2012 - I live in Winter Park (Orlando) Florida. I have been gifted two potted cypress trees that I need to get into the ground. The only place I can plant them is in my backyard in between a stand of non-inv...
view the full question and answer

Trees poisonous to horses from Landrum SC
April 15, 2012 - Please tell me if the following trees are poisonous to horses: hickory, beech, poplar, and redbud. Thank you very much.
view the full question and answer

Evergreen trees for California that are non-toxic for dogs
February 19, 2014 - Hi, we live in California, San Bernardino County and would like to know what evergreen trees are safe to plant in our backyard with 2 little dogs being around. I did quite some search online but ever...
view the full question and answer

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