Q/A column – for release August 20, 2009

Dan Culbert - Extension Horticulture Agent 

Buggy Ficus, Spreading weeds, cottony crud and an empty office:

 How Does Your Garden Grow?

 

The heat of summer may have driven gardeners inside to beat the heat, but a few brave souls have ventured out to discover many different problems in their Florida Yards.   We are planning a full schedule of fall programs for 4-H’ers, ranchers, and gardeners, but local Dairy producers will have to wait a bit longer before they can get help; see the last question to see why…

 

Buggy Ficus

Since the Hurricanes, I’ve planted several Banyan trees in my yard to provide shade and privacy.  In the back by the canal, my trees are showing some kind of little black spots on the leaves, which are also folded and curled.  What is going on? –Henry

You brought in a sample from your tree, and even though these large trees have multiple roots and a wide canopy, they are not the large-leaved Banyan Tree.  Instead, it is a close relative called Weeping Fig; botanically we call them Ficus benjamina. 

A few years ago (2003), a new insect came to Florida (What a surprise!).  This one is called the Ficus Thrip; thrips are small insects that feed on tender, new foliage.  Their feeding causes sunken, reddish spots on leaves.  Leaves tend to curl and fold inward, and if you open them up the small (1/8 inch), fast moving pests can be seen running for cover.

While the appearance of the leaves may suffer, it takes a large amount of feeding to cause leaf loss on Ficus in landscapes. They are most commonly seen in late spring and early summer.   I’d advise most homeowners not to worry about them.  UF Entomologist Catherine Mannion has found that there are several predators and parasites that can keep them under control - as long as insecticides are not used.

Since this plant is also kept indoors as a house plant, their appearance inside may be a bit more of a problem. And if you are a nursery grower, you definitely want to consider using the expensive systemic insecticides that can eliminate these insects.  Research has shown there are a few products that work for commercial growers, but since the results are still being checked out, it would be best to contact me if you want specific insecticides for this pest.

A couple other ideas on this problem: large Ficus trees in the landscape have shallow roots that can get into water pipes or septic tanks and, and they blow over in hurricanes.  Know a cheap plumber?  Large blown-over trees mean big cleanup costs; do you really want these in your Florida Yard?  And there’s another problem:  if the leaves of your Ficus (or Banyan) are actually dropping off, it may be the Ficus Whitefly.  Now that bug is a REAL problem we can cover another time.

 

Spreading Lawn Weed 

I sent you a couple pics of some weeds that are taking over my yard, as well as others in my area.  I think these weeds are going to be a big problem... can you please tell me what they are? Thank you so much for the info, Greg

You sent me a couple pictures of a weed called Chamberbitter, a.k.a. Gripeweed.  Botanically known as Phyllanthus urinaria, it is native to Asia but is seen throughout the Gulf States.  This annual weed spreads aggressively and can quickly take over landscape beds and then move into the turfgrass.  It germinates in early summer through early fall.  Chamberbitter is usually introduced from weedy nursery stock.  Be careful of the bargain-priced nursery plants that could bring this weed into your Florida Yard.

 These plants range from 2 to18 inches in size and can grow in shade or full sun conditions.  The leaves a like little mimosa leaves, each leaf with many leaflets. The most distinct feature are the numerous small, smooth, warty fruits attached to the bottom of the foliage.  Gripeweed produces a great number of viable seeds.  Once it sets seed, control is difficult.   

One way to get a handle on this creepy herb is to pull it out by hand.  DON’T shake off the soil from the roots, as you can easily shake off the seed. Collect the weeds and put them in a lawn trash bag; you don't want the seeds of Chamberbitter spreading around your yard.

If the problem cannot be managed by pulling, consider herbicides.  To battle chamberbitter in the lawn apply a pre-emergent herbicide when the soil starts warming up; around here around the first of April. The weedkiller to use will depend on the kind of turfgrass you are growing.  Herbicides for landscape beds will be more complicated, co contact us if you need recommendations.

 

Pink Hibiscus Mealybugs

My Hibiscus plant has all these curled up leaves on the tips.  When I look closely I see little white fluffy spots on the leaves, stems and even on the bark.  Is this some kind of a fungus? ~ Betty

Welcome to the wonderful world of the Pink Hibiscus Mealybug.  Usually mealybugs are not pink but white in color.   They are sapsuckers, and just like the thrips we talked about above, they like tender new leaves and stems to satisfy their sap-sucking habits.  The clear sticky waste material is called honeydew, and it is a great place for black sooty mold to grow on many kinds of plants.

Your mealybugs are the dreaded Pink Hibiscus Mealybug (PHM), so named for its light pink color and the color it shows when squished.  It identifies it as this new problematic insect four in Florida since 2002. 

 Dealing with these critters puts the gardener between a rock and a hard place.  Using harsh, expensive systemic insecticides will only partially control PHM, and will kill of many of the good guys (parasites and predators) that are slowly adapting to feeding on this mealybug.  Best management ideas include pruning out severely infested branches, and placing the cuttings into the regular home trash (rather than trying to add it to a yard trash pile). Don’t cut ff more than a third of any new branches.  The use of insecticidal soaps and horticultural oils will slow down but will not eliminate PHM.

 

The larger greenish gray growths you have on more woody parts of the stem are lichens.  They are NOT a problem and do not need control.  They are clinging ON the outer surface of the bark but do not invade inside living tissue of the host plant.  Lichens are a fascinating cooperative arrangement between a fungus and an algae, just taking ups space because there is enough light and moisture for them to grow there.

 An  Empty Desk……

I’ve noticed it’s been pretty quiet around the Okeechobee office lately, and there are a lot fewer staff meetings, and I’ve had to pitch in on some of those office management tasks that used to be taken care of.  What Gives? ~Joe

Well in case you haven’t heard, our illustrious leader for the past 25 years in Okeechobee County, O. Patrick Miller, has hung up his shingle and is now officially enjoying retirement.  We wish him well and thank him for his service.  If you want to see a little more, visit our website and follow the links on our webpage to his retirement page.  Best Wishes and Many thanks, Pat from all YOUR staff and the people of Okeechobee, Florida. 

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 questions for today are REAL questions that have been asked in the past few days.  To continue the column, we need YOUR real questions. Be sure to include your name and phone or email address in case we need more information

More information is available on the Okeechobee Extension web page, http://okeechobee.ifas.ufl.edu. If you need additional information on velvet ants, 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. Millie Ferrer, Interim Dean.

 References  

Chamberbitter

Jordi, Rebecca.  Weeds – Chamberbitter.” Callahan:  UF/IFAS Nassau County Extension Service, 2006.  http://nassau.ifas.ufl.edu/horticulture/questions/weeds.html

Wilber, Wendy L. “Chamberbitter weed.” [Weekly Home Horticulture Column].   Gainesville: UF/IFAS Alachua County Extension Service, August 2005.   http://alachua.ifas.ufl.edu/lawn_and_garden/ask_wendy/fall_2005.shtml#chamberbitter

Williams, Larry.  “Be persistent in battling common chamberbitter.{Tallahassee Democrat Newspaper Article].”  Tallahassee: Leon County Extension Service, August 29, 2002. http://leon.ifas.ufl.edu/News_Columns/2002/082902.pdf

Pink Hibiscus Mealybug

Culbert, D.  "Are your mealybugs Pink?'  Okeechobee: UF/IFAS Extension Service, 2/9/05. http://okeechobee.ifas.ufl.edu/News%20columns/Pink%20Mealybugs.htm

ibid. "What's that in my tree?" Okeechobee: UF/IFAS Extension Service, 2/17/05. http://okeechobee.ifas.ufl.edu/News%20columns/Whats%20In%20My%20Tree.htm 

Hoy, M. A.,   Hamon, A. and Nguyen, R.  Pink Hibiscus Mealybug, Maconellicoccus hirsutus  [EENY-029].  Gainesville:  UF/IFAS Extension Service, March, 2008.    http://edis.ifas.ufl.edu/IN156

Osborne, Lance.  The Pink Hibiscus Mealybug Management [webpage].  Apopka: UF/IFAS Mid Florida Research & Education Center,  May 19, 2009. http://mrec.ifas.ufl.edu/lso/PinkMANAGE.htm

Pat Miller

             Go to this link: http://okeechobee.ifas.ufl.edu/PatMiller.Retires.htm