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
2 ratings

Tuesday - March 25, 2008

From: Schertz, TX
Region: Southwest
Topic: Compost and Mulch, Vines
Title: Few blooms on native Bignonia capriolata (cross-vine)
Answered by: Barbara Medford

QUESTION:

I have an 8-year-old crossvine that has grown and bloomed beautifully until this year. During the winter it lost all of its lower leaves. What leaves were left had brownish-red splotches on them. It has begun to grow now and has a few blooms at the very top of the trellis. The new leaves look healthy green--no splotches. Two questions: 1. Are the splotches on the old leaves significant? (I can send a picture if you want to see) and 2. How can I get leaf coverage (and ultimately flowers) again on the lower 4/5 of the trellis?

ANSWER:

Two vines that are frequently confused with each other are Bignonia capreolata (crossvine) and Campsis radicans (trumpet creeper). Their blooms and growth habit are very similar, thus the confusion, but the trumpet creeper tends to be much more aggressive, putting out suckers and sometimes damaging structures. We will assume you have crossvine, and the solutions for both are basically the same.

The sudden leaf loss is a little disturbing, but a late frost, or the plant being allowed to get excessively dry might have produced that problem. This is a plant with no significant insect or disease damage, but might sometimes show small spots of sooty mold or mildew. This could be the product of poor circulation. We are inclined to believe it is something in the culture of your plants, rather than pests, that is causing your problems. Basically, flowering bushes need more sun and less nitrogen. If your plant is not getting a lot of sunlight, it can survive, tolerating shade, but it will not bloom as well. And, if you have been fertilizing with a high nitrogen lawn fertilizer, that can certainly cut down on blooms. If you wish to fertilize your crossvine, switch to a high phosphorus formula just before blooming period.

Finally, we suspect that your plant needs a good grooming. Many gardeners cut it down very severely after the bloom period. This will always inspire a plant to try to do better, before it gets taken down altogether. It may be putting so much energy into growing those thick stems that little is left over for blooms and leaves, but every plant needs to bloom in order for the species to survive. Not only that, trimming may also permit more sun to reach the bulk of the plant, as well as improving the air circulation. Crossvines like lots of water (but can survive pretty dry) and nutrients. Compost mixed into the soil will both add nutrients and improve drainage around the roots. So, basically, feed it a little better, maybe water a little more, give the soil a nice dose of nutrients, cut out the nitrogen-high fertilizer, and tidy the plant up once or twice a year. It's a very tough native plant, and your hummingbirds will thank you for what you do.


Bignonia capreolata

Bignonia capreolata

 

 

 

More Vines Questions

Pruning time for Lonicera sempervirens from Pflugerville TX
August 08, 2011 - Dear Mr. Smarty Plants, When does the Wildflower Center prune its Lonicera sempervirens?
view the full question and answer

Is there a vine in Indiana with poisonous thorns?
December 27, 2011 - I was cut at the left big toe by a brownish/red thorny vine while tracking thru dry grass near the bridge exiting 278. I'm from Indianapolis, in 46208. Was wondering if I was exposed to a poisonous v...
view the full question and answer

Allergic reaction from vine in St. George Island, FL
July 24, 2010 - In the panhandle of Florida, we have a vine that looks like a blackberry vine. Seems to be poisonous. It has thorns that are dark purple and leaves a blistery, itchy rash. The leaves are green and ruf...
view the full question and answer

Transplanting trumpet creeper in Prairie City, IA
August 22, 2011 - I have a Trumpet Creeper that I would like to transplant. How do you do that?
view the full question and answer

Is Bignonia capreolata (Crossvine) known to cause skin irritation
July 23, 2013 - Is Crossvine (Bignonia capreolata L.) known to cause a rash? We are trying to identify the source of a rash-after-gardening, and have not seen any of the big three (poison ivy, poison oak, poison suma...
view the full question and answer

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