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
Not Yet Rated

Tuesday - January 02, 2007

From: Leander, TX
Region: Southwest
Topic: Propagation
Title: Rhizobium inoculant for Leucaena and othr leguminous tree seedlings
Answered by: Nan Hampton and Joe Marcus

QUESTION:

What sort of Rhizobium inoculant would be appropriate for Leucaena and other leguminous tree seedlings?

ANSWER:

It is correct that legumes such as White Leadtree (Leucaena leucocephala) and, as another example, bluebonnets, require Rhizobium bacteria to enable them to fix atmospheric nitrogen for use by the plant. Furthermore, there are different strains of Rhizobium and the strains that are effective for bluebonnets are not necessarily effective for Leucaena. The Rhizobium strains are species specific. It is possible that the proper strain of Rhizobium is present in your soil already. You can check this by looking at the roots of your Leucaena. If there are nodules present, then it already has the correct Rhizobium species. If you have access to mature Leucaena plants, you can simply harvest some soil from around the roots of them and inoculate your seedlings' soil with some of it. It would only take a very small amount per pot. You could mix a handful or two of native soil into a pile of potting soil and that should do the trick—nothing fancy; the roots and the Rhizobium will find one another.

Research in Australia has cited two strains of Rhizobium that are effective with Luecaena. In acid soils Strain CB3060 (TAL1145) was most effective in N2 fixation. This is cited in Tolerance of Leucaena to Acid Soil Conditions by F.P.C.Blarney and E. M. Hutton, p.84. In the article "Establishment and Early Growth of Leucaena" C. M. Piggin et al., p. 87, report strain CB81 was found reliable and strain NGR8 less reliable. They also report (p. 88) CB3060 (TAL1145) is good in acidic soils as well as more neutral soils.

Unfortunately, there are few sources for obtaining Rhizobium cultures. I did find one source, Becker Underwood in Australia with worldwide production and marketing, for purchase of CB3060. The USDA has a Rhizobium Germplasm Collection that provides free cultures for research but they do not have a database of strains available. You can see a list of other bacterial culture collections worldwide.

For a good discussion of seed treatment and nitrogen fixation see Agroforestry for the Pacific Technologies from the U. S. Forest Service and also Nitrogen Fixing Tree Start-up Guide from Agroforestry.com.

You can also check with the Williamson County Extension Office of the Texas Agricultural Extension Service and see if they know of the availability of Rhizobium strains.

 

More Propagation Questions

Gregg's Mistflower stressed in Fredericksburg TX
August 07, 2013 - My Gregg's Mist Flower plants are very stressed. The blooms have turned brown and the leaves are drooping. Plants are receiving moderate sun, partial shade. Do they need daily watering this time o...
view the full question and answer

Can two species of Muhlenbergia be cross-pollinated from Portal AZ
July 17, 2012 - Will Muhlenbergia lindheimeri (Big Muhly) cross-pollinate with Muhlenbergia porteri (Bush Muhly)? I am attempting to restore the grasslands on my private property to a pre-1900 state. Bush Muhly was a...
view the full question and answer

Removing competition of mustang grapes from live oaks
January 26, 2006 - We have several native mustang grape vines on our rural property that seem to be taking over the live oaks on which they are becoming entwined. Is it advisable to remove them or are they harmless? And...
view the full question and answer

Student wants pointers to increase germination rate of Salvia farinacea in Lubbock, Texas
October 06, 2010 - I am a student at Texas Tech, studying environmental horticulture. I have been doing research on Salvia farinacea as well as a number of other natives. I've just been assigned a project to increase t...
view the full question and answer

Germination and propagation of Carolina larkspur
September 02, 2007 - I have some Delphinium carolinianum seeds and I am looking to germinate and propagate them. I threw some out on my caliche rubble Four years ago,and got one to germinate four years later. What time o...
view the full question and answer

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