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?


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

Friday - September 09, 2016

From: Bandera, TX
Region: Southwest
Topic: General Botany, Propagation, Trees
Title: Propagating a white cultivar of Texas Mountain Laurel (Sophora secundiflora
Answered by: Nan Hampton


I am trying to propagate a white cultivar of the Texas Mountain Laurel. I plan to use bee sticks and pollinate the plant. Are the plants self fruiting or do I need to find another white mountain laurel somewhere to try and do this? What would be a good item to cover the blooms with to avoid promiscuity?


First, let's talk about the breeding system of Sophora secundiflora (Texas mountain laurel).  They have perfect flowers with both male and female components within each individual flower.  The flowers of Texas mountain laurel are typical "pea" flowers with the stigma (female part) and the stamens (male parts) enclosed within the keel of the flower.  This would seem to be an ideal setup for self-fertilization inside the unopened keel of the flower.  However,  the very fragrant flowers are enthusiastically visited by bees and other insects that are able to push inside the keel to obtain the nectar and, in the process, collect pollen.  It is VERY unlikely that the flowers self-fertilize in this way.  However, we don't have any information as to whether the flowers are self-compatible or not.  In other words, if a bee visited one flower on the tree and then brought the pollen from that flower to a different flower on the tree, would the pollination result in fruit?   It is certainly worth trying to pollinate the flowers with pollen from other flowers on the tree. 

If you have access to another Texas mountain laurel with white flowers, it would be good to try using pollen from that tree, too, because, even if the flowers on the same tree are self-compatible, the introduction of genetic diversity is likely to increase the amount of fruit set over those of the self-pollinated flowers. That said, you need to realize that white cultivars can be from mutations of different genes and the combination of the two might result in the two compensating for the mutation that the other has and not resulting in white flowers at all.

An article on Wikipedia discusses pollination bags and lists bags made of different materials and their characteristics.  There is also a set of criteria for a good pollination bag.  Among those criteria are that the pollination bag:

  • be made of material strong enough to withstand abrasion from wind, rain, birds, etc.
  • be porous enough that air and moisture is able to pass through, but not so porous that pollen grains can enter
  • allow the penetration of sunlight so that photosynthesis can continue to occur to tissues within the bag

The main criteria for a good pollination bag should be that ambient conditions are maintained within the bag while preventing the entrance of pollinators or wind-blown pollen.

Here are some suppliers of pollination bags that I found on the Internet:

You can find more suppliers by searching the Internet for "pollination bags".

The pollination bag that you use will be tied around the stem of the flower cluster as soon as the flower buds form to prevent insect pollinators from entering the flowers.  In order to prevent injuring the stem, you can first wrap a cotton ball around the stem before you tie the bag, with a string or twist tie, securely around the stem.

Finally, you could make your own bee sticks, buy pollination wands or use a small paint brush like Gregor Mendel used in his famous pea plant crosses.


From the Image Gallery

Texas mountain laurel
Sophora secundiflora

More Propagation Questions

Stubs of Texas Star Hibiscus in Abilene, TX
March 26, 2009 - We have cut back our outdoor Texas Star Hibiscus for 4 years and now have a large number of old stubs that the new growth must navigate around. Will it kill the plant if we dig up the old stubs? At so...
view the full question and answer

Dividing blackeyed susans in Lake Ronkoko NY
July 06, 2009 - How are you supposed to divide blackeyed susan's? And when is the best time to do this?
view the full question and answer

Speeding up growth of Hesperaloe parviflora (red yucca)
January 12, 2012 - I have germinated Hesperaloe parviflora, Red Yucca, for our Caddo Native plant sale. I have kept in the cool greenhouse for 2 months and they are about 2 inches. A friend put one outside and they froz...
view the full question and answer

Hollies not retaining leaves in Tulsa
August 10, 2008 - I have Little Red Hollies that have lost their leaves, some areas being bald. They are also not full - you can see through them. These were planted in this condition Spring of '08 and have been wat...
view the full question and answer

Variety of colors in bluebonnet seeds from Houston
November 18, 2013 - Bluebonnet seeds I have collected are a variety of colors, from the sandy/tan color to a grayish color and black color. Are all variations viable? Are they equally viable?
view the full question and answer

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