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?


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
Not Yet Rated

Thursday - August 18, 2011

From: The Woodlands, TX
Region: Southwest
Topic: Compost and Mulch, Watering, Drought Tolerant, Trees
Title: Difficulty of watering at drip line of trees from The Woodlands TX
Answered by: Barbara Medford


I'm watering my couple dozen native mature trees to make sure they survive this drought and its aftermath..and I'm reading about how to water at the drip line. But..all of my trees' drip lines extend over other trees, patios, sidewalks, neighbors' yards, houses, garages, etc. And my property is rumpled with miniature slopes and ridges that send water trickling in all sorts of directions. So should I just soak my entire yard every time I see one tree in the crowd that starts to show yellow leaves? I had been soaking the targeted trunks previously, and that seemed to have been working. What do I do?


So, this is our second chapter of Gardener Survival in a Texas Summer. The first chapter, also for you, is this previous Mr. Smarty Plants question.

Your specific concern this time seems to be concerning mature native trees. We have had several questions about our reference to "drip line." Since roots of large trees will ordinarily go out far beyond the drip line, if you have a lot of trees, yes, you are going to have to cover a lot of ground. Soaking the trunks with water is not what we recommend. Too much moisture on the bark of a tree can invite disease and fungi. Our suggestions to push a hose down in the soil around the tree and let the water drip slowly has to do with young, newly planted trees.

No, we don't think you should soak a yard when one tree shows yellow leaves. Those yellow leaves could be early Fall color because of our extreme drought. We realize some of your trees are under or over other trees, but all of the roots are in the ground, and it's the roots you need to be watering. There is not much you can do about roots under sidewalks, patios and so forth, and some of the roots under foundations or driveways may be causing you problems having nothing to do with where they are being watered. Roots go where they do in search of water and nutrition; if it happens to be under your house, pulling the water out by the tree could be causing settling of your foundation. We always urge people planting trees to stay well away from hardscape of any kind, especially structures.

But you probably had trees on your property, since we know the area in which you live, and you sure want to preserve them if you can. If some of the roots go into your neighbors' yard, some of theirs are probably in your yard. Be responsible neighbors and follow the watering restrictions to water the lawn, gardens and soil under which you know you have tree roots. If you have bare ground, we suggest mulching. That will hold in moisture, help cool the roots and, as it decomposes, add organic material to the soil to aid in drainage and nutrition. Do not pile the mulch up around the trunk-another opportunity for insects and mildew to move in.


More Watering Questions

Replacing Drought-Stricken Cedars
January 16, 2012 - Hello, I live in Williamson County on a couple acres. We have several dead cedars as a result of drought; we're reluctant to cut them down because many of them provide a friendly barrier between us...
view the full question and answer

Landscaping plant for Austin
September 01, 2011 - Great site! Have gotten lots of ideas. We're about to start construction on a fairly major landscaping project: raised beds/privacy screen. We're at the top of a hill in the Hill Country just wes...
view the full question and answer

Why are the leaves on my Laurel hedge turning brown in Everett, WA?
February 22, 2010 - Our laurel hedge seems to have brown leaves on the top of the bush. We haven't had a freezing winter so we are trying to figure out why some of the leaves are brown.
view the full question and answer

Watering Houseplants with Soapy Water
August 22, 2011 - I accidentally watered my house plants with a container that had a some dishsoap in it. Will they be okay? One of the plants is a 20yr old cactus, with small roots.
view the full question and answer

Transplanting a Texas redbud sapling
July 27, 2008 - I've just discovered a Texas red bud sapling (baby tree)that decided to grow next to our fire pit. Although there's no reason for us to sit around the campfire in 100 degree weather, I would like to...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center