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

Smarty Plants on mockoranges
May 25, 2005 - I live in Colorado where it is common to have 1 or 2 late frosts. I planted 4 littleleaf mockoranges (Philadelphus Microphyllus) 2 years ago and they are pretty much in full sun most of the day. I h...
view the full question and answer

Problems with recently planted trumpet vine from Worcester MA
October 20, 2012 - Dear Mr. Smarty Plants, I have a question about my recently planted Trumpet Vines. First of all, I live in Massachusetts, zone 6. The soil is perfect for the two vines, which I bought from a local nur...
view the full question and answer

Red, puffy growths on Concord grape vine
July 07, 2015 - I have a growth on my grapevine that is red and puffy almost looks like it is full of water. It is a Concord grapevine. I have images I can send to you! It is on the stems.
view the full question and answer

Cause of yellowing buffalo grass (Bouteloua dactyloides)
June 07, 2008 - We are getting large yellow areas in our buffalo grass lawn and think this is probably due to grub worms. Are grub worms the likely culprit and if so, what is the best way to get rid of them? We don...
view the full question and answer

Care of a live oak with decay and perhaps fungus on trunk
July 14, 2011 - I have a huge live oak on my property in Salado that just lost a very large branch. The branch had decay in the center and also has a variety of bugs in it, espeically since it has been on the ground...
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