by Molly Jameson | Aug 28, 2019
Vaseygrass produces prolific seed heads, and once introduced, can be spread easily by farming equipment. Photo by Herman Holley.
Beware Vaseygrass, an Aggressive Exotic Weed
A couple months ago I got a concerning call from a local small farmer. Rich Pouncey, of Bumpy Road Farm in northern Leon County, was very troubled by an unwelcome visitor he found growing on his farm.
Rich, who grows multiple crops, including heirloom corn varieties to create his delicious cornmeal and grits, noticed something amok in a portion of his rows. With closer inspection – and a visit from Extension Agent Les Harrison – it was identified as vaseygrass (Paspalum urvillei). Vaseygrass, an aggressive exotic species from South America, was starting to take complete control of a large section of Rich’s small growing space he had reserved for upcoming collard production.
With its abundant seed heads and our consistent summer rainstorms, vaseygrass quickly took over a section of Rich’s field. Photo by Molly Jameson.
Rich, who prides himself on supporting biological diversity, soil health, and native pollinators, uses strictly organic growing methods in raising his crops. Therefore, the presence of such an aggressive exotic was truly of grave concern.
Rich is not sure exactly how this weed was introduced to his fields. He suspects it may have been hidden in a soil amendment he purchased, but he cannot be certain of the source. It is certainly a reminder to be careful when bringing in outside equipment, mulch, and any new agricultural products.
When mature, vaseygrass can grow to six-feet tall with plentiful seed heads, and it flourishes in warm, wet conditions. It spreads by seeds and has very high rates of germination during times of abundant rainfall. The grass is low in nutrition – making it a poor choice for grazing cattle – but in a hay field, it will spread like wildfire if not controlled.
Vaseygrass is a true perennial bunch grass, with a small root system and, fortunately, few rhizomes. Rich began pulling and black bagging as much of the grass as he could each day, but struggled to keep up, and it quickly spread through more than a tenth of an acre of his field.
When hand pulling wasn’t enough, Rich switched to solarization, hoping to kill emerged vaseygrass seedlings and seeds with heat. Photo by Herman Holley.
About six weeks ago, Rich changed strategies and began solarizing the area with clear plastic sheeting. Tightly covering soil with clear plastic sheeting in the warmest summer months can trap heat and increase temperatures, potentially killing weeds, pests, and diseases within the top foot of the soil surface. He will find out soon if this control strategy has been successful, as he’ll be pulling up the plastic in September. He knows that if the solarization is not successful, he may have no choice but to use chemical control methods, which will mean he will have to wait years to grow any crops in this area he wishes to market as organically grown.
If hand pulling isn’t enough, small infestations of vaseygrass can be controlled by spot spraying a one percent glyphosate solution at 1.2 ounces/gallon. Be aware, mowing and tilling can make the problem worse, as the scattering and burying of seeds can exacerbate the infestation.
For more details about identifying and controlling vaseygrass, read the UF/IFAS EDIS publication, Identification and Control of Johnsongrass, Vaseygrass, and Guinea Grass in Pastures (https://edis.ifas.ufl.edu/ag372).
If you suspect vaseygrass is growing on your property, contact your local county extension agent to get the grass properly identified and help spread the word about its presence.
by Daniel J. Leonard | Jun 25, 2019
‘Needlepoint’ Perennial Peanut in the author’s lawn.
What began as my journey toward a turf-less lawn in September of 2017 is finally beginning to come together! In the fall of 2017, I installed about 120 one-gallon-sized ‘Needlepoint’ Perennial Peanut (Arachis glabrata) plants, purchased from Sunset Specialty Groundcovers in Live Oak, FL, on roughly 20” centers in my front lawn, an oddly shaped (650 ft2) patch of ground that had been previously filled with spotty centipedegrass and a healthy and diverse weed population. 18 months later, the peanut has almost completely filled in, shaded out all the weeds, and blooms nonstop!
Looking back, I definitely learned a few lessons the hard way. First, you should mulch bare ground in between plants at time of installation. Because there are few herbicides labelled for residential use on this crop and I didn’t want to experiment on my new “lawn”, I spent a lot of time on my hands and knees (much to the amusement of my neighbors and folks driving by) pulling weeds in the first two years that could have been prevented with mulch. Second, have a plan for keeping the perennial peanut in bounds once it has filled in the area it was supposed to and begins to travel into adjacent landscaped beds! The area my peanut inhabits is surrounded on two sides by inescapable concrete. It was on the other two sides, however, that I have had to improvise after they came under siege (literally under, because perennial peanut spreads by underground rhizomes). Installing some sort of edge blocker at planting and vigilance with routine mechanical edging is a must to keep it in bounds! Third, I recommend that you have a counter-argument prepared when the peanut goes dormant in the winter and your wife asks why the yard is bare dirt!
‘Needlepoint’ Perennial Peanut overhead shot showing complete ground coverage in the author’s lawn.
Overall, though there are a couple of things I would have done differently, I’m extremely pleased with my lawn of perennial peanut. It is absolutely stunning in the warm months, incredibly low maintenance, and unique! Plant some today!
As always, if you have any questions about perennial peanut or any other plant/crop, contact your local UF/IFAS Extension office.
by Matt Lollar | May 27, 2019
Nobody likes weeds in their garden. Weeds are not only ugly, they can host insects and diseases that later spread to your garden. This situation commonly occurs when weeds belong to the same plant family as the desired landscape or vegetable species, but some insects and diseases have diverse palettes. For example, I recently witnessed a looper caterpillar on a pokeweed plant.
Looper damage on a pokeweed plant. Photo Credit: Matt Lollar, University of Florida/IFAS Extension at Santa Rosa County
Loopers are common pests of vegetable gardens and in the landscape. Probably the most common loopers found in North Florida gardens are cabbage loopers (Trichoplusia ni) and soybean loopers (Chrysodeixis includens). Cabbage loopers can be found feeding on cabbage, of course, as well as leafy greens, cucumbers, tomatoes, chrysanthemums, and snapdragons. Weeds that attract this looper are lambsquarters, dandelions, and curly dock. Soybean loopers like to feed on sweet potatoes, tomatoes, watermelons, geraniums, and sunflowers. They can also be found feeding on oxalis, kutzu, and lantana.
Looper found on pokeweed plant. Photo Credit: Matt Lollar, University of Florida/IFAS Extension at Santa Rosa County
Although weeds can be hosts for pests, they may be used advantageously. Trap crops can be planted at a garden’s perimeter or windward portion to attract pests away from the desired crop. A trap crop draws the pest crop away from the main crop. The trap crop is then destroyed or sprayed with insecticide when the pest insect is found feeding on it. This allows for a reduction or elimination of insecticidal use on the desired crop. However, it is important that both the trap crop and the desired food crop or ornamental crop are regularly scouted to keep track of pest populations.
For more information on trap crops and other insect and disease diversion methods you can read the EDIS Publication: Intercropping, Crop Diversity and Pest Management.
by Matt Lollar | May 17, 2019
Are you looking for more selective herbicide options for annual beds and around shrubs and trees? The Santa Rosa County Extension Office will be hosting guest speaker Dr. Chris Marble from the UF/IFAS Mid-Florida Research & Education Center on Thursday, May 23. Dr. Marble is a Nationally Renowned Weed Scientist who has published numerous research and extension publications. 2 CEUs available in LCLM, Limited Lawn & Ornamental, Commercial L&O, O&T, Natural Areas, ROW, and Private Ag. Pre-registration fee is $15, or $20 registration at the door the day of the event (includes lunch and resources). Pre-register online at Eventbrite Ticket or bring cash, check, or money order to the Santa Rosa County Extension Office, 6263 Dogwood Dr., Milton, FL before May 23. For additional questions, please contact Matt Lollar at mlollar@ufl.edu or 850-623-3868.
SCHEDULE
9:30 Registration & Welcome
9:45 Presentation Begins
11:30 Question & Answer w/Dr. Marble
11:45 Evaluation & CEUs
12:00 Lunch & Discussion on Glyphosate Registration
12:30 Adjourn
by Matt Lollar | Apr 9, 2019
The UF/IFAS Extension and FAMU will be bringing the Florida Pest Management Conference to Milton on April 17th. Attend to earn CEUs for your PCO License. Attendance is free and we are currently seeking sponsors at $80 per sponsoring business/organization. For more details and to register, please visit the conference webpage at Northwest Pest Management Conference.
by Larry Williams | Feb 26, 2019
Florida pusley is common summer annual weed. Photo credit: Larry Williams
If weeds were a problem in your lawn last summer, the coming weeks are the time to apply a pre-emergence herbicide to prevent their emergence again this spring and summer.
Timing of a pre-emergence herbicide application for summer annual weeds such as crabgrass should be during February when day temperatures reach 65° to 70°F for four to five consecutive days. This generally coincides with when azaleas and dogwoods first begin to bloom. This in not when these plants are in full bloom but when the first flowers begin to open along the lower branches, particularly on azaleas. Note: This timing is not true for chamberbitter. Chamberbitter requires warmer soil temperatures to germinate. Apply a pre-emergence herbicide during April when battling chamberbitter.
Most pre-emergent type herbicides won’t work when applied after weeds are visible. The product must be applied just before seedlings emerge.
The weeds growing now in local lawns are not summer annuals. Summer annual weed seeds are still dormant awaiting warmer spring temperatures to germinate and emerge.
Most of the weeds in yards now are winter annuals. A few include annual bluegrass, chickweed, henbit, hop clover, lawn burweed and wild geranium.
Winter annual weeds in lawn. Photo credit: Larry Williams
A pre-emergence herbicide should have been applied during October to help prevent these weeds.
A few common summer annual weeds include crabgrass, Florida pusley, chamberbitter, sandspur, spotted spurge and doveweed.
If your lawn has a history of summer annual weeds, one control option is to apply a pre-emergence herbicide. Timing is critical in order for pre-emergence herbicides to work.
Look for lawn pre-emergence products that contain the active ingredients oryzalin, benefin, pendimethalin, DCPA or bensulide.
For season-long weed control, a second application may be needed about six to nine weeks after the initial application. To activate some products, irrigation or rain may be necessary following application. Because pre-emergence products may interfere with lawn grass seed germination, delay re-seeding six to sixteen weeks after application.
Overuse of some types of pre-emergence herbicides can cause a lawn to produce short stubby weak roots. So only apply the product if there is a pest to control – in this case, if you have had a history of summer annual weeds. Otherwise, save your money and time. Use pre-emergence herbicides only on lawns that have been established for at least a year. These products can severely injure newly planted lawns.
It is the user’s responsibility to read and follow all label directions and precautions when using any pesticide, including herbicides.
