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
1 rating

Friday - June 29, 2012

From: Austin, TX
Region: Southwest
Topic: Watering
Title: Drip irrigation and uneven distribution
Answered by: Nan Hampton and Andrea Delong-Amaya


Subject: Drip irrigation and uneven distribution. Iíve installed drip irrigation in an area of mature shrubs (St. Johnís Wort) in Austin. These have previously received about ĺ inch of water once a week from an oscillating sprinkler, so the water was uniformly applied. Iíve placed four of the new drip irrigation emitters within the 7-foot diameter drip line of each shrub. Because each emitter saturates only about a 20-inch diameter, the water now is not applied uniformly. Even if I provide the same amount of water to a shrub as before, will the uneven distribution of water within the root area pose any problem to the shrub, particularly premature browning or uneven growth?


Installing a drip irrigation system is a very wise move on your part since the City of Austin Water Utility managers are considering allowing homes with drip sprinkler systems to be allowed to water any day at any time and to not have to comply with the officially-assigned watering day.   Installing the drip sprinklers is especially wise since they deliver water to the roots and not into the air where runoff can occur or much of the water evaporates before it can reach the roots.

To answer your question I thought it wise to consult an expert—a Super Smarty Plants—Andrea DeLong-Amaya, chief horticulturalist at the Wildflower Center.   Here is what Andrea says:

"It will depend on what species of St. John’s Wort he is growing, but four emitters on a 7 foot dripline will not provide adequate coverage for a shrub the size of the most commonly planted Hypericum sp. in our area (with a spread of 3-4 ft.). I would suggest he get closer to the dripline. Four emitters per plant should be adequate if they are closer."

So, it looks as if you will have to do a little work and move those emitters closer to the plant and to each other to minimize the areas that don't receive water.


More Watering Questions

Care of Live Oaks
July 11, 2012 - We have Two Young Live Oaks in the front of Our home. We had them treated for insects, ect. Now what can we do to make them Full Green and Happy Happy Happy again.Thank You
view the full question and answer

Shy blooming non-native Crape Myrtle, in Littlestown Pennsylvania
July 25, 2011 - My Crape myrtle has been planted about three years, and reached a height of about 4'. It blooms late July and for the past two years, has only had one or two blooms on it. I have a lot of buds whic...
view the full question and answer

New growth on live oaks in Houston
September 27, 2011 - My 2 10yr. old live oaks are putting out new growth (branches?) although, here in Houston, TX we are having such a drought. For the last 3 months, I have conscientiously watered my entire yard via ...
view the full question and answer

Ilex vomitoria Sufering from Drought?
January 19, 2012 - My Ilex vomitoria has always thrived. It is about ten years old. This fall, a portion of the leaves on the ends of the branches have turned yellow on the edges with green veining in the center. Othe...
view the full question and answer

Drought affecting native trees from The Woodlands
August 18, 2011 - I've been trying to grow native trees in my yard for the past 3 years and I'm starting to question whether the amount of time required to spend watering them during the long hot season in Texas is r...
view the full question and answer

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