Thursday, May 30, 2013

No Yard is an Island: Cottony Trampweed is in the Wind

For all those who work to maintain a lawn composed of just one kind of plant (Zoysia grass, or Centipede grass, or Bermuda grass, or Fescue grass, for example), UGA Turfgrass Extension Associate Becky Griffin has this timely reminder:

"Your neighbor’s weed problems are YOUR weed problems.  This trampweed (Facelis retusa) spreads by windblown seeds.  This means that if your neighbor’s lawn looks like this picture, chances are your lawn could look like this next year.  Working with your neighbors to address lawn problems can be a great community builder, and can create a beautiful neighborhood."
 The Trampweed she refers to is pictured below.
Lawn that is awash in the cottony puffs of Trampweed.                                                       PHOTO/Becky Griffin

UGA Extension Agent Frank Watson, in the FACES article "Weed Covers Turfgrass with Snowy Appearance," points out that seeds of Trampweed germinate in the fall and early winter, which means that May and June are not the months for trying to treat the lawn for this weed. Right now, this annual weed is producing its seeds and dying. 

However, Watson does suggest some other tasks that might be done - beginning now -  to reduce the weed's success in following years: "... since this weed is found on droughty sites with low fertility, make an effort to improve the turfgrass density by applying lime, fertilizer or increasing irrigation."

For appropriate chemical controls and the best timing for their use, contact your county Extension office.

Tuesday, May 28, 2013

Green Industry Updates

UGA's Green Team will be presenting Green Industry Updates around the metro area this summer.

The first will be in Cherokee County on Wednesday, June 12, at the Hoke O'Kelley Auditorium on campus at Reinhardt University, 7300 Reinhardt Circle, Waleska, GA, 30183.

 This is the schedule:
9:00 – 9:55 a.m.
New Herbicides for Problem Weed Control in Turf
Dr. Patrick McCullough
UGA Crop & Soil Sciences
10:00 – 10:55 a.m.
Identification & Management of Ornamental Plant Diseases
Dr. Jean Williams-Woodward
UGA Plant Pathology
11:00 – 11:55 a.m.
Using “New” Insecticides in Turfgrass IPM
Dr. Will Hudson
UGA Entomology

The next Green Team GIU will be in Dekalb County on Wednesday, July 17, at the Dekalb Extension Training Center, 4380 Memorial Drive, Decatur, GA, 30032.

This is the schedule for that day:
9:00 – 9:55 a.m.
Turfgrass Disease IPM 2013 and Beyond
Dr. Alfredo Martinez
UGA Plant Pathology
10:00 – 10:55 a.m.
Turf Insect Control
Dr. Will Hudson
UGA Entomology
11:00 – 11:55 a.m.
Pest Management:  It Starts with Healthy Turf
Dr. Clint Waltz
UGA Crop & Soil Sciences

According to the flyer that came to this office, both events qualify for 3 hours (category 24 or 25) Commercial Pesticide Credit, 1 hour Private Pesticide Credit, and 3 hours ISA Arborist Credit, but call to verify.

For both, registration and check-in begin at 8:30 a.m. Both sessions will conclude by 12:30 p.m.

Events are $15 each, which includes materials and refreshments, and a discount applies when registration is for both events.

To register, visit, or contact Beth Horne at 770-228-7214 or

Monday, May 13, 2013

When the Onions Send up Flower Stalks

Many area gardeners who planted onions this year are looking out over onion patches that are punctuated by flowering stalks, also called seed stems. The onions will still be eat, but this condition does reduce the keeping quality and ultimate size of the mature bulbs.

Unfortunately, the same problem is affecting onions in Georgia's best-known onion-producing region.

An article in the 2 May issue of UGA's Family, Agricultural, Consumer and Environmental Sciences newsletter,  Fluctuating Weather Patterns Reduces Vidalia Onion Crop Yields, includes a note about how many of this year's Vidalia onions have developed the seed stem condition:
"In some farmers’ fields, upwards of 70 to 80 percent of the onions had seed stems, said Reid Torrance, a Vidalia onion expert with University of Georgia Cooperative Extension who has been serving the Tattnall County onion-producing area since 1984."
Mr. Torrence has more to say about this year's abundance of seed stems:  “It’s hard to pin down exactly what triggers the onions to develop seed stems,” he said. “But I think these huge fluctuations in temperatures we had this year contributed to it. Anything that shocks the plant can cause it to develop a seed stem.”

Clemson University's Onion, Leek, Shallot & Garlic publication agrees with Mr. Torrence's statement about the probable cause for this condition:
"Onions will bolt (produce a flower stalk) if exposed to a prolonged cold period following a favorable growing period. This results in small bulbs with large necks which are hard to cure and generally unusable. The larger the plants are at the time of exposure to the cold period the higher the rate of bolting.
To help prevent bolting:
  • Select onion sets of an inch or less and transplants about 6 inches high and about half the thickness of a lead pencil.
  • Plant at the correct time for your area.
  • Avoid high fertilizer rates applied in the fall."
Many gardeners believe that trimming off the flowering head of the seed stem will result in larger onions than if the heads are left, but the Texas Aggie Horticulture publication Growing Onions  has this to say about cutting off the flowering stalks:
"What can one do if flower stalks appear? Should the flower stalks be removed from the onion plants? Suit yourself but once the onion plant has bolted, or sent up a flower stalk, there is nothing you can do to eliminate this problem. The onion bulbs will be edible but smaller. Use these onions as soon as possible because the green flower stalk which emerges through the center of the bulb will make storage almost impossible."
Normally, storing mature, harvested onions in a cool, dry, dark area is enough to keep them good for several months, but onions affected by seed stem will not keep for very long even under optimal storage conditions.
Gardeners who have a fairly large crop of affected onions may want to share them with neighbors and friends so they can be used while they are still good.

Alternatively, the National Center for Home Preservation offers information on blanching and freezing onions for later use excerpted from UGA's wonderfully helpful book So Easy to Preserve.

Friday, May 10, 2013

Will we see periodical cicadas in Georgia this year? Guest post by N.C. Hinkle

Remember the great periodical cicada emergence we had here in Georgia back in 2011 – the “Great Southern Brood”?  The Northeast is having its own periodical cicada emergence this year, but unfortunately it is highly unlikely that we will see much of Brood II here in Georgia this year.  
2011 Periodical Cicada                     PHOTO/ N.C. Hinkle

Information from a 1988 publication hints that periodical cicadas may show up in the very northeastern corner of the state, so Rabun, Townes, Union, White and Habersham counties may see periodical cicadas, but it’s doubtful they’ll show up anywhere else in the state. 

It looks like our next periodical cicada emergence will be in 2017, with anticipated Brood VI cicadas showing up possibly in the northern third of the state.  Brood X will show up in 2021 and “the Great Southern Brood,” (the one that was such a hit in 2011) will return in 2024.

If you want to view the distribution maps for yourself, there are some good ones at

Of course, by late June we’ll have our annual “dog day” cicadas popping out around the state.  They’re 50% larger than the periodical cicadas, but are green and lack the bright red eyes.  And they certainly don’t occur in numbers like the periodical cicadas.  Nevertheless, we’ll hear them singing in the trees every afternoon, providing a lovely backdrop to our summer activities.


N. C. Hinkle, Ph.D.
Dept. of Entomology
Univ. of Georgia