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
14 ratings

Sunday - August 03, 2008

From: Arroyo Grande, CA
Region: California
Topic: Invasive Plants, Non-Natives, Pruning, Shrubs
Title: Pruning of Grape Kool Aid Plant in California
Answered by: Barbara Medford


I have a Grape Kool Aid plant and was told it would grow to 6 or 7 feet tall, but it is well over that and I need to know if I can prune it and if so how?


Is this a test? Is somebody out there trying to trick Mr. Smarty Plants into making a mistake? Well, it's not hard, but maybe we dodged the bullet this time. Turns out there are two plants referred to as Grape Kool Aid Plant, one native to Texas and New Mexico and one to Africa.

Our first thought was that you were referring to Sophora secundiflora (Texas mountain-laurel. The flowers of this tree (see pictures below) are said to smell like grape Kool-Aid. Personally, we never stick our nose into flowers pollinated by bees, but that's what we're told. At the Lady Bird Johnson Wildflower Center we are devoted to plants native to North America, and planted in the area to which they are native, because they are accustomed to the conditions and will require less water, fertilizer and maintenance. The Texas mountain laurel is basically a desert tree, a legume with very poisonous seeds but absolutely beautiful in the blooming season of February and March. A member of the Fabaceae (pea) family, it is native to the Texas Hill Country and is often found growing among granite rocks. We did find indications that it is being grown in California, but found no information on pruning it. Ordinarily, pruning for shape and to remove damaged limbs would be about the limit. Dispose of prunings carefully, as all parts of the plant are poisonous. We always recommend pruning during the dormant season, mid-winter in California.

On the other hand, we suspect that you may have Psoralea pinnata in your garden. This is a native of Africa, also a member of the Fabaceae family, which blooms in Spring and again in late Summer. It grows 8 to 10 feet tall and 10 feet wide. The flowers also are purple and smell grapey, so maybe it's the color, who knows? Again, we found no information on pruning, but would still recommend pruning for shape. It is a short-lived tree but is prolific in seedlings and suckers. It is, in fact, classified as an invasive in Australia, so that might be a risk in California which is such a good place to grow, invasives love it. Again, prune in mid-winter. 

Probably the only way you can be sure which plant you are dealing with is the leaves. On this page of images of Psoralea pinnata, you can see that the foliage is needlelike, although we understand it is soft and non-allergenic. In contrast, as you can see from the pictures below, the foliage on the Texas mountain laurel has shiny, leathery compound leaves made of 7-9 leaflets that are rounded at the ends.

Sophora secundiflora

Sophora secundiflora

Sophora secundiflora

Sophora secundiflora





More Invasive Plants Questions

Control of invasive sandburs in Austin
May 05, 2014 - My attempts to control / eradicate Sanbur with pre-emergent corn gluten twice yeary for the last three years have been unsuccessful. My post emergent pulling weeds for 15 years has also been unsucces...
view the full question and answer

Invasive native wild onions in East Granby CT
May 17, 2011 - I have wild onions which have become extremely invasive. I have no idea how to get rid of them, and this year they seem to have taken over my entire flower bed. I tried pulling the bulbs out for sever...
view the full question and answer

Non-native, invasive peanut butter tree from Canby, OR
July 17, 2012 - I too have a peanut butter tree with the pink and white blooms, its about 5 years old and is beautiful, but 2 weeks ago it started wilting and losing all its leaves, I am afraid it is dying. Can I sav...
view the full question and answer

Clover Among the Bluebonnets in Round Mountain, Texas
April 13, 2012 - I have a beautiful yard of bluebonnets, but mixed in with them are a tall clover that is hiding the flower's beauty and a shorter plant with clover-like leaves that produces burrs. Pulling is not an...
view the full question and answer

Forget-me-nots choking a spring in Bethlehem PA
June 20, 2013 - Hi Mr. Smarty Plants, I am restoring a native plant area along a spring that feeds directly into our local creek. Right now the spring is becoming choked with forget-me-nots, that I am trying ...
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.
© 2015 Lady Bird Johnson Wildflower Center