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
1 rating

Sunday - July 20, 2008

From: Houston, TX
Region: Southwest
Topic: Container Gardens
Title: Failure of potted verbena to bloom
Answered by: Barbara Medford

QUESTION:

I have a trailing purple verbena that won't bloom. It is in a container, not in the ground, and gets lots of sun. What is the problem?

ANSWER:

In our Native Plant Database, there are 36 species with the name "verbena" in the name of the plant, most members of the genus Glandularia. Probably the most-used native verbena is Glandularia bipinnatifida (Dakota mock vervain). We are pretty sure that what you have is some sort of a hybrid, with different colors, as that is what is usually available in commercial nurseries. Since we don't know, and you were probably not given any indication, what hybrid this would be, we can only deal with your question on a general basis. This website from GardenGuides.com Verbena can give you some more care information, regardless of the species. In cooler climates, verbena are considered annuals, but in Houston, you should be able to get it to perennialize. You said it was in a container, so you need to make sure the container drains very well. The verbena needs moist soil until it is pretty well-established, but cannot tolerate soil that does not drain well, and may develop disease because of the poor drainage. The native verbena mentioned above blooms from March to October. Although our webpage on the verbena says it needs part shade, which we define as 2-6 hours of sun a day, other websites say that verbena needs full sun, up to 8 to 10 hours a day of sun. A plant that needs lots of sun to bloom is not going to do well in a more shaded location. If blooms seem to slow during the summer, you might trim the whole plant back by about 1/4, and hopefully it will recover its vigor and bloom again. Dedheading is important on this plant but, again, just trimming across the top to take off spent blooms should suffice, instead of snipping off each individual blossom. If your plant has lush foliage and no flowers, we suspect the plant food you are giving it is heavy on nitrogen, which promotes green leaves. Switch to one that has a higher phosphorus content, the number in the middle of fertilizer designations, and see if that will inspire your plant to bloom.

 

From the Image Gallery


Prairie verbena
Glandularia bipinnatifida

More Container Gardens Questions

Plants for planting in gourds
March 15, 2009 - I enjoy painting dried gourds. This spring I got the idea to paint a gourd and cut holes in the side and plant some small blooming flowers. I have seen "hen and chickens" growing out of holes in the...
view the full question and answer

Plants for indoor container gardening from Lax Vegas NV
May 10, 2013 - What is an good flower to grow in a pot? I live in a apt., and like roses,tulips etc. if that helps any.
view the full question and answer

Replanting a blue agave in Rio Rancho NM
January 11, 2010 - I have acquired a Blue Agave, approximately 4-5 ft high. It still appears quite healthy. It was used over the holiday season for display purposes in a liquor store. Unfortunately, the root ball has be...
view the full question and answer

Huisaches in pots from Houston TX
May 20, 2012 - I have special (and probably weird) affinity to huisaches (acacia farnesiana). As a child I used to admire the three that elegantly guarded our backyard looking almost like fingers reaching for the s...
view the full question and answer

Plants for hanging flower boxes from Austin
July 27, 2013 - I have two long flower boxes 17" x 15" x 25 feet long one on the north side of the apt and one on the south made of metal suspended about four feet from the ground. One will get the morning sun and ...
view the full question and answer

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