Native Plants

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

Not Yet Rated

Monday - February 25, 2008

From: Pflugerville, TX
Region: Southwest
Topic: Trees
Title: Life expectancy for Carolina buckthorn (Frangula caroliniana)
Answered by: Nan Hampton and Joe Marcus

QUESTION:

Someone recently told me that Carolina buckthorn only lives 4-5 years and I'm wondering if that is true. I had a nice one (on Blackland) that died suddenly in its fourth or fifth year, during the drought of '06 (with supplemental watering). Do you know the normal life expectancy of this plant?

ANSWER:

No, we don't have an exact life expectancy for Frangula caroliniana [syn. = Rhamnus caroliniana] (Carolina buckthorn). None of the standard tree guides (Robert Vines' Trees of Central Texas or Trees, Shrubs, and Woody Vines of the Southwest or Benny Simpson's Field Guide to Texas Trees) give an indication of lifespan for this small tree, nor do the more extensive plant manuals (Shinners & Mahler's Illustrated Flora of North Central Texas and Manual of the Vascular Plants of Texas by Correll and Johnston). The only source we found that does is the Texas Plant Information Database from Texas Parks and Wildlife which says it has slow growth and is short-lived. Other sources (Texas Tree Planting Guide and the Georgia Wildlife Federation) say that its growth is moderate. We do know that most sources agree that its maximum height is usually 15-20 feet, although some specimens may reach 35 to 40 feet. So, if we have a definition of what slow or moderate growth is, we can make an educated guess at normal life expectancy. As it turns out, we do have a definition. Michael Dirr in Manual of Woody Landscape Plants says:

"The designation slow means the plant grows 12" or less per year; medium refers to 13 to 24" of growth; and fast to 25" or greater."

So, if we take the upper end of slow (1 ft/year), it could take the tree 20 years to reach its maximum growth. If we take the upper end of medium (or moderate), it could take 10 years to reach its maximum growth. If we take the mid-range between the two, I think we could estimate the trees could live 15 to 20 years. Of course, that doesn't guarantee your tree will live that long; but, then, it might live longer than 20 years.

In our experience, Carolina buckthorn (especially the nursery-grown material) does seem to be susceptible to root and crown diseases—specifically, crown rust of oats according to University of Florida Extension Service. Jill Nokes in How to Grow Native Plants of Texas and the Southwest says that the terminal stem and leaves of plants 4 or 5 feet high in five-gallon containers may suddenly turn brown and the plants quickly die. She also says that transplanting into larger containers after seed germination often causes death of as many as 30% of the plants. She doesn't give a specific disease that causes these deaths.