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
Not Yet Rated

Monday - March 28, 2005

From: SF, CA
Region: California
Topic: Diseases and Disorders
Title: Pustules on geranium
Answered by: Joe Marcus

QUESTION:

I have a geranium that has developed oblong red/brown pustules/raised bumps on the undersides of the lower leaves. The foliage around the bumps is stil green but everything else has yellowed

ANSWER:

Thank you for writing! The problem you describe sounds like oedema (sometimes spelled: edema; pronounced: ed-ee'-ma). Oedema is not a disease, but a physiological disorder. It is a problem with many plants, but is an absolute disaster for geraniums (Pelargonium X hortorum) -- especially ivy geraniums (P. peltatum). Native geraniums are not as affected by the condition. Oedema is a result of ruptured cells, usually on the underside of a leaf, caused by a complex of issues involving water availability, humidity, temperature, air movement, and plant nutrient levels. In severe cases, the plant will drop the injured foliage, sometimes denuding the plant. The University of Georgia Cooperative Extension website has a nice article on Geranium Diseases including a section on oedema.
 

More Diseases and Disorders Questions

Lantana in hanging basket not blooming in Dover PA
June 23, 2010 - We have a lantana Bandana trailing gold in a hanging planter in full sun. It hardly blooms. Any suggestions?
view the full question and answer

Smarty Plants on lantana in Dallas
September 14, 2005 - For several years, the lantana plants in my backyard in Dallas grew and bloomed all Summer and Fall until the first real cold snap. I've loved having a native plant that didn't need constant care a...
view the full question and answer

Problem with unknown tree in Austin, Texas
July 23, 2013 - Have recently moved to Austin, Texas and have a tree in my backyard that has been dropping leaves and one major branch appears to be dead. That branch has hard rust colored sap circles (about penny si...
view the full question and answer

Various landscape problems in Omaha, NE.
June 18, 2015 - Thank you for your time, sorry i cant sort this out because my issue seems to fit many but also none of the issues I've read about. Some patches of grass in my lawn have yellow spots and dying and/or...
view the full question and answer

Disease-resistant squash varieties for Central Texas
February 03, 2008 - Can you give me names of some disease-resistant summer squash varieties available in Central Texas?
view the full question and answer

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