Feature Article – for release September 17, 2008

Dan Culbert - Extension Horticulture Agent 

 How Does Your Garden Grow?

The local County Extension office has been asked by local newspapers papers to try out a question/answer column.  So – here goes:  Send us your favorite garden question by fax (863-763-5901), email ( okeenews@newszap.com) or just drop it off at the Okeechobee News  office at (107 SW 17th St. suite D, Okeechobee, FL 34974).  The University of Florida - Okeechobee County Extension office will pick out three questions that would be of greatest interest to local residents and publish brief answers in the Okeechobee News.

The questions for today are REAL questions that have been brought in to the Extension office in the past few days.  To continue the column, we need YOUR real questions by Wednesday at 5 PM. Be sure to include your name and phone or email address in case we need more information (We can publish a question as anonymous if you wish).   Clear photographs (digital preferred) may also be submitted, but they might not be able to be returned.  Do not drop by actual plant specimens (unless it is a prize tomato for our salad or a beautiful flower for our office!)  We reserve the right to edit all questions for space.  The answers will be placed on the Okeechobee Extension website the week after the appear in print;  they will include links to additional references.

Spots on my Grapefruit

I have a mature grapefruit tree that was doing just fine – until all the tropical rains came and flooded my back yard.   Most of the fruit has just fallen on the ground, and when I looked at it, they had small raised black spots on leaves.  What are these spots and did they cause my fruit to fall?

The small raised black spots on your grapefruit leaves are signs of a citrus plant disease called Melanose.  This is a fungus that causes blemishes but is not serious enough to cause the fruit to fall.  Melanose is managed by removing any small dead twigs, keeping the leaves dry, especially in springtime, and if necessary, preventative fungicides may be sprayed.   As far as the falling fruit, it is not unusual for citrus trees that have been in standing water for several days to drop their fruit.   Unless you can dig a bigger pond, a deeper ditch or can convince the authorities to quickly take their water back, fruit drop will often result from these late summer tropical deluges.

 Reference:   UF/IFAS Extension Dooryard Citrus Pest Guide  http://edis.ifas.ufl.edu/HS122#SECTION_1.3  

 

 I have this plant growing in my yard.  It’s easy to take care of and grows easily from seed.  The problem is, the leaves look like a “well known” plant that is very illegal.  Can you tell me it’s name and a little more about it so I don’t get in trouble with the law or get too curious neighbors bent out of shape.

The plant you have is called Coral Plant; botanists call it Jatropha multifida.  It is a tropical plant that grows in full sun, almost any kind of soil, and needs little water. Bright red clusters of flowers and large round seed pods should give a hint this is not the other plant you are thinking about.  The sap can irritate skin and the plant is poisonous if eaten.  (Other species of this Jatropha are called Bellyache bush, purging nut, and black vomit nut.)  If curious pets or kids are around, this might be a poor landscape plant choice.

Reference:  Refer to archived column at: http://okeechobee.ifas.ufl.edu/News%20columns/Jatropha.htm.  Another good image is available at http://commons.wikimedia.org/wiki/Image:Jatropha_multifida_Blanco2.342.png

 

Coral Tree Gall   

I am a teacher in Okeechobee but I brought in a piece of a plant growing in my yard in St. Lucie county.  The ends of all the stems on my Sunshine Tree are all swollen, the leaves are distorted and it doesn’t seem to grow any more.  What’s going on and how can I fix this problem?  

If you had not given me the name of this plant, I would have been stumped.  This plant is also known as the Coral tree (Erythrina variegata var. orientalis).  The stem is infested with a new invasive pest that produces abnormal growth know as galls.  The Erythrina gall wasp (Quadrastichus erythrinae) lays eggs inside the succulent new growth of this tree and are misshapen by the burrowing larva of this insect.  Scientists are looking at insecticides that are applied to the roots and absorbed by the roots.  Dade County Agent Adrian Hunsberger suggests that any new Coral tree is planted and drenched; other agents are not recommending that this beautiful tropical tree be used until natural predators are found to keep this galling pest under control.

References: For info on tree: http://edis.ifas.ufl.edu/ST238.  For info on the pest: http://www.doacs.state.fl.us/pi/enpp/ento/gallwasp.html 

 

More information is available on our award-winning Okeechobee web page, http://okeechobee.ifas.ufl.edu. If you need additional information on , please email us at okeechobee@ifas.ufl.edu or call us at 863-763-6469.  Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our Okeechobee County Master Gardeners from 1 to 3 PM on Tuesday afternoons.  Go Gators! 

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Trade  names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.  Florida Cooperative Extension Service / IFAS / University of Florida.  Larry A.  Arrington, Dean. Last update: 09/18/2008.  This page is maintained by Dan Culbert