Rent Shop Volunteer Join

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

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
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

QUESTION:

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?

ANSWER:

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 Shrubs Questions

Landscaping help for Gilmer, TX
September 01, 2008 - We have just moved to the beautiful hot state of Texas from warm California and we need some help! Our roses are dying, we have a patch about 25ft. by 3ft. that gets the rain run off like a little str...
view the full question and answer

How to Control Poison Ivy
February 22, 2016 - We have lots of Poison Ivy on a site we are clearing it is adjacent to a pond and children are around this area all the time. We are creating hiking paths. I have a lot of experience but I do not wan...
view the full question and answer

Native plant for border in central coastal Texas
September 29, 2015 - I am looking for a native plant suggestion for a border along my front porch in central coastal Texas. My site has heavy gumbo soil and strong sunlight. I want something not more than 2 or 3 feet t...
view the full question and answer

Roses being attacked by spider mites
January 18, 2008 - My roses are being eaten alive by spider mites. I read that this area of Texas has a huge problem with these devils! I've tried everything to kill them to no avail! Can you help me? Gratefully yours,...
view the full question and answer

Privacy screen from Simpsonville SC
May 04, 2013 - My neighbor cut down his part of our shared woods so now we see his whole "outside patio area". What kinds of fast growing shade loving trees and shrubs can we plant on our property line that will c...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.