En EspaŅol

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 - July 30, 2009

From: St. Louis, MO
Region: Midwest
Topic: Pollinators, Compost and Mulch, Herbs/Forbs
Title: Failure of tall garden phlox buds to open in St. Louis MO
Answered by: Barbara Medford

QUESTION:

Why won't the buds of my tall garden phlox open? Plants are apparently healthy, no powdery mildew or visible insects, foliage looks great and buds are profuse but they don't open. I have two clumps in different areas, both get full sun. I gave one clump a high phosphorous bloom booster fertilizer but it didn't help. The bees love the closed buds all the same. This happened last year too.

ANSWER:

Tall Garden Phlox are hybrids of Phlox paniculata (fall phlox), which is native to Missouri.  However, hybridized plants can present a problem, as you don't know exactly what their parentage is, and what attributes of the original plant were edited out and what others were added in to gain more height, different colors, longer blooming time, etc. We found an excellent website, Tall Garden Phlox for Minnesota Gardens, from University of Minnosota  Extension. We realize you are not in Minnesota, but the principles should apply. Please read the whole article but some of the things you should probably give attention to are:

The amount of sun (you already said you had full sun).

The soil being well-drained yet retaining adequate moisture; this may require incorporating a generous amount of organic material (compost, etc.) before planting. Plant grows best when it's moist.

Good air circulation to prevent mold, and watering soil, not sprinkling from above, for same reason.

Light application of balanced fertilizer as new growth emerges each Spring, again just before plants begin to flower. Not too much nitrogen, and don't use lawn fertilizer, which is high nitrogen. The high nitrogen encourages leaf development (as in grass) at the expense of flowering. 

 

 

 

More Compost and Mulch Questions

Shriveling and dying of non-native impatiens
July 14, 2008 - Several years now many of my impatiens after a month or so seem to shrivel up and eventually die. They are planted in a row and not all are affected. I am not noticing any slug evidence which I would...
view the full question and answer

Ground cover to withstand dog traffic in Michigan
November 02, 2010 - I need a soft ground cover that will grow in sand, and be able to take four big dogs that love to run in the yard. Grass just doesn't make it. Someone suggested that groundcover might work. Thanks...
view the full question and answer

Spreading compost from Kyle TX
January 22, 2012 - I'm trying to find if there is some type of "implement" to help spread compost in my yard that is easier than a shovel and rake. Any ideas?
view the full question and answer

Native plants for a bioswale in Baltimore
July 22, 2009 - What native plants would suit a bioswale in an urban part of Baltimore City? The clay soil gets waterlogged and the site has part shade.
view the full question and answer

Live oak leaves turning yellow after planting in Houston
December 19, 2011 - We bought a 65 gallon live oak in early October, and have been watering fairly heavily three days a week. It seemed OK, then all of a sudden lots of the leaves are turning yellow. Is it getting too ...
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
© 2014 Lady Bird Johnson Wildflower Center