En EspaÑol

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Thursday - October 01, 2009

From: Thornwood, NY
Region: Northeast
Topic: Container Gardens, Pruning, Seasonal Tasks, Herbs/Forbs
Title: Overwintering Cardinal Flower in Thornwood NY
Answered by: Barbara Medford

QUESTION:

I have 6 Cardinal Flower plants in planters. They have mulch on top to keep them moist. Can they stay in the planters all winter? Do I cut the stalks before winter comes or leave as is?

ANSWER:

Lobelia cardinalis (cardinalflower) is native to New York and to Westchester County, on the southeastern tip of New York. It is hardy from USDA Hardiness Zones 3 to 10; you are in Zone 6a, with minimum average annual temperatures of  -10 to -5 deg. F, so it would seem the answer to your question is yes. The only reservation we have is that the roots will be in planters instead of the earth. When roots are in the ground, the whole earth is insulating them from the cold. In a planter, they are insulated by the mulch on top of the soil, a few inches of potting soil, and whatever the planter is made of. If it is possible, it would be better if the containers were situated in front of a sunny wall, where the day's warmth from the sun would be re-radiated back out to the nearby plants. If that is not possible, we still think the roots of this plant will be all right, just do everything you can to protect them from freezing temperatures. 

 

From the Image Gallery


Cardinal flower
Lobelia cardinalis

Cardinal flower
Lobelia cardinalis

More Seasonal Tasks Questions

Spring care for Garrya ovata from Pflugerville, TX
February 24, 2014 - Hello again, Mr. S-P, I planted a Mexican silktassel in April 2012 (purchased at the WFC). It has done well, but the leaves are bronzed and splotchy from this winter's freezes. All the stems are...
view the full question and answer

Trimming of Aster ericoides in Philadelphia
March 20, 2010 - Should I cut back my Aster ericoides, ‘schneegitter’ in the spring?
view the full question and answer

Deadheading Mexican hat to produce more blooms in Austin
July 05, 2010 - I have several Mexican hat (rudbeckia) plants growing wild in my yard. Would deadheading now give them a second flush of bloom in fall?
view the full question and answer

Native plants for Summer Planting in Vernal UT
May 24, 2011 - What are the native plants that I could plant this summer in Vernal, Utah
view the full question and answer

Winter care for plants in Austin
December 05, 2008 - Hello, I'm just getting into the gardening thing, and have planted tons of plants this fall here in Austin. I'm a bit worried about them with winter right around the corner. My first question is r...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2015 Lady Bird Johnson Wildflower Center