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?


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

Wednesday - November 14, 2007

From: Glendale, AZ
Region: Southwest
Topic: Diseases and Disorders
Title: Navel orange disease problems
Answered by: Barbara Medford


I live in Glendale, Arizona. I hav a mature miniature navel orange tree. This year it has lost a considerable amount of leaves. Also the fruit all has a large yellow spot. It looks pitiful. What should I do?


We found an excellent site on dealing with problems with the navel orange trees. We really tried to find one from Arizona but couldn't, so you'll have to accept this Texas Cooperative Extension site, instead. Then, if you're really dedicated to find a solution, go to this site, "Diagnosing common citrus problems", and see what you can find that fits your situation.

As in a great many plant problems, especially, it would seem, with trees, plant stress gets a lot of the blame. One reference said that orange trees should be fertilized 6 times a year, starting in early March through August/September. Maybe your tree is just hungry. Or, if the trunk is not above the surface of the surrounding garden, or there is mulch spread over the root zone, the tree may be developing root rot or foot rot. Charming terminology. It look to us like the experts were pretty nonchalant about most of the problems with navel oranges, with comments like "not worth treating", etc. It's up to you to plow through that chart on citrus problems and see if it's worth it to you.


More Diseases and Disorders Questions

Leaves dropping on native Texas Mountain Laurel in San Antonio
September 20, 2008 - Please help. We have a beautiful TX Mountain Laurel in our front yard. This year the leaves are dropping like snow in the north. What do you think is wrong with our tree?
view the full question and answer

Trumpet Vine Dropping Buds
July 25, 2013 - My trumpet vine is dropping its buds before flowering. This happened last year as well. Do you know what is causing this and what I can do to prevent it?
view the full question and answer

Controlling mildew on Gaillarida sp.
August 11, 2005 - Any suggestions for controlling mildew on blanket flower? It's spreading throughout my garden.
view the full question and answer

Fuzzy Citrus Fruit on Satsuma and Lemon Trees
September 13, 2014 - A man asked you about fuzzy little small fruit-like balls that looked like tiny lemons. I have huge numbers of these on both my mature Satsuma and lemon tree this year. I get 100's of really great f...
view the full question and answer

Yellowing foliage on a lemon cypress from St. Charles MO
May 22, 2011 - I recently received a lemon cypress tree as a gift. After about a month we transplanted it outside and the foliage turned from a light green to a yellow color. Is this normal? The tree doesn't app...
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.
© 2015 Lady Bird Johnson Wildflower Center