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?

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

Wednesday - June 06, 2012

From: Woodbridge, ON
Region: Canada
Topic: General Botany, Soils, Herbs/Forbs
Title: Weak stems on asters and ironweed from Woodbridge ON
Answered by: Barbara Medford

QUESTION:

My question is in regards to plants flopping over. My smooth asters and ironweeds never seem to have strong stems. Is because the soil is too fertile or maybe too shallow?

ANSWER:

You may be eligible for the "I stumped Mr. Smarty Plants award!" We found an answer but it was talking about marigolds, but we think it's possible the same answer may be true for your plants. Read this article from eHow Why do Flowers on Marigolds Bend? From that article:

"Overhead watering may cause stem breakage and bending if blossoms become saturated; always water at the base of the plants.

Marigolds are heliotropic, meaning their flowers and leaves turn toward the sunlight whether the plants are grown indoors or out. Cells near the base of the blossoms control the bending, by shrinking or enlarging to move the flowers toward the light source. By keeping marigolds in full sunlight all day, you'll help avoid this survival mechanism and keep flowers from possibly bending away from main focal areas of the garden."

There are four species of the gender Vernonia (ironweed) native to Ontario: Vernonia fasciculata (Prairie ironweed)Vernonia gigantea (Giant ironweed)Vernonia missurica (Missouri ironweed) and Vernonia noveboracensis (New york ironweed). Symphyotrichum laeve var. laeve (Smooth blue aster) is also native to Ontario. You can follow each plant link to our webpage on that plant to see if you get any clues of what you might be doing wrong in terms of soil or watering of those plants. We did some extra research on heliotropism, which obviously occurs in many plants.

We checked all of these ourselves and concluded that all could do well in moist, fertile soils and full sun. About the only possibility that presents itself to us, since we cannot see the plants, is the caution against overhead watering, which can weigh down large heads of flowers, thus bending the stem.

 

From the Image Gallery


Giant ironweed
Vernonia gigantea

Missouri ironweed
Vernonia missurica

Smooth blue aster
Symphyotrichum laeve var. laeve

More Soils Questions

Limp leaves on Texas purple sage in Magnolia TX
July 22, 2010 - Recently planted Texas purple sage, some of it looks healthy and has new blooms, but a few of the plants have limp leaves and are thin at the bottom. I read the article on cotton root rot, but am not ...
view the full question and answer

Adapting to clay soils in British Columbia
April 11, 2006 - What can I use to break down the clay content in my flower bed. It has a high concentration of clay and I want to plant treat it so I can plant flowers in it.
view the full question and answer

Plant mistakes from Cedar Park, TX
April 09, 2014 - At our "Wilts End" in Cedar Park, TX. and are looking for a tall shrub/tree that will hide a 6-ft tall concrete wall and muffle the noise from a busy street. The wall forms a very wide-angled V shap...
view the full question and answer

Native plants for poorly drained clay soil
March 24, 2008 - I am trying to establish a native plant garden in my back yard, I have two places where water stands for a few hours after a heavy rain, and the soil is black clay. Can you recommend any perennials 3...
view the full question and answer

Help with composting in Katy TX
March 19, 2010 - I've gone on line and tried to figure out what I'm doing wrong with my compost pile. What exactly is the proper ratio, and the types of plant matter and layers to achieve the optimum decomposition i...
view the full question and answer

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