Host an Event Volunteer Join Tickets

Support the plant database you love!

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
3 ratings

Saturday - March 02, 2013

From: Boulder, CO
Region: Rocky Mountain
Topic: Invasive Plants, Vines
Title: Passionflower Vine for Boulder
Answered by: Anne Van Nest

QUESTION:

I would love to have a passionflower vine growing up an arbor. I have read comments online that indicate: 1. I can grow some types of passionflowers in Colorado. 2. The plants can become very invasive. Do I need to worry about the invasiveness of these plants in Colorado? If I want to be certain of containing the roots can I put some type of barrier in the ground to keep plants contained? Any suggestions and how deep should the barrier go? Which varieties will grow in CO? Thanks so much for advice!

ANSWER:

There are about six (depending on how taxonomists group which plants together) native Passiflora (passionflower) vines in the United States. Exquisite in bloom and great screening plants, these vines can mostly be found in the warmest parts of the country. There are two that can tolerate colder winter weather conditions and could be possibilities for your garden in Colorado. The hardiest native passionflower vines are Passiflora incarnata and P. lutea.

Boulder, Colorado is in the USDA plant hardiness zone 5b/6a so these plants will need to be located in a protected site, given lots of extra mulch to insulate the roots and will die down to the ground during the winter.  A plentiful amount of continuous snow cover is also an excellent insulating blanket for the winter.  If it is too risky to grow these two passionflower vines outdoors in Boulder, then consider planting them in large containers and moving the containers into a garage or basement for the winter.  Then move them out to the garden in late spring.

The native passionflowers are: Passiflora affinis (native to TX), Passiflora foetida (AZ, FL, HI, and TX), Passiflora incarnata (DE to MO) Hardiness zone 5-7 to 10. Passiflora lutea (PA to FL) Hardiness zone 5 to 9 and tolerant of winter temperatures down to -15 or -30 deg. C. Passiflora suberosa (TX), and Passiflora tenuiloba (NM to TX).

There are no worries about any Passiflora becoming invasive in Colorado. The areas where native or exotic passionflower vines are an invasive issue are locations such as Hawaii where there is not a winter freeze to control the plant. A good resource for invasive plant information is the Invasive Plant Atlas of the United States developed by the University of Georgia - Center for Invasive Species and Ecosystem Health and the National Parks Service (among other partners).

 

From the Image Gallery


Bracted passionflower
Passiflora affinis





Maypop
Passiflora incarnata





Yellow passionflower
Passiflora lutea

Bird wing passionflower
Passiflora tenuiloba

More Invasive Plants Questions

Getting rid of King Ranch bluestem
August 13, 2008 - I have recently moved to South Texas Coastal town of Portland, Texas. My St. Augestine turf grass has been invaded by - what the neighbors tell me - King Ranch Blue Stem grass. I am having a terribl...
view the full question and answer

Creeping buttercups in juniper in McKeesport PA
May 22, 2010 - I have creeping buttercups in my juniper ground cover. How do I get rid of them.
view the full question and answer

Eliminating evasive Celastrus orbiculatus (Oriental bittersweet)
July 21, 2013 - I have Oriental Bittersweet growing pervasively in my shrub garden, strangling my shrubs and growing into my beautiful Victorian porch. I can't keep up with it! What can I do?
view the full question and answer

Landscaping a new yard in El Paso, TX
July 01, 2010 - I am starting my back yard, we want to plant some sod grass and shade trees. We were doing some research and came across the Paulownia and the Royal Empress tree. I like them since they grow very fast...
view the full question and answer

Plants for delineating property line
July 18, 2010 - I have a neighbor who does not mow his grass or take care of a strip that runs between my property and his. I would like to plant some inexpensive, low maintenance, shrubs, that would do well in full...
view the full question and answer

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