by Sheila Dunning | Sep 7, 2019
“There are these weeds spreading all over my yard. They have little round leaves that are real close to the ground and creep in every direction. I keep trying to get rid of them by mowing my grass shorter, but they are killing my grass. What are they and how do I get rid of them?” Here at the Extension office, this is a conversation I have had nearly daily for the past month. We are here to help with identification and control of many landscape problems, including weeds.
However, my first word of advice is to change the mowing practice. Short, spreading weeds cannot be mowed out. You need to do just the opposite. Mowing as high as possible (3-4”) will help to reduce weeds by shading them out, therefore, reducing their spread.
In every instance, the weeds have been common lespedeza (Kummerowia striata (Thunb.) Schind syn. Lespedeza striata) and/or prostrate spurge (Euphorbia maculata syn. Chamaesyce maculata). Both grow close to the ground with a spreading habit. Both have small, rounded leaves and produce small, light-colored flowers. But, if you look close, there are significant differences that will help with identification.
Common lespedeza, also known as Japanese clover, is prostrate summer annual that forms 15-18 inch patches. The stems are wiry. It has dark green trifoliate 
(arranged in threes) leaves with three oblong, smooth leaflets. Leaflets have parallel veins nearly at right angles to a prominent mid-vein. Its leaves have smooth edges and a short spur at the tip of each leaflet. Flowers appear in late summer with small pink to purple, single flowers found in leaf axils on most of the nodes of the main stems. As common lespedeza matures, the stems harden and become woody.
Prostrate spurge is a summer annual broadleaf weed that spreads by seed. The leaves are oval in shape, small, and opposite along the stem. As it matures, a red spot may form in the center of the leaf, earning it the common name spotted spurge. Another distinct characteristic is the stem contains a milky sap that oozes when the stem is broken. Light pink to white-colored flowers appear from early-summer through the fall.
Both are annual,broadleaf weeds, so there are several post-emergent herbicides available to kill the ones present. Don’t forget the pre-emergent herbicide application in late winter though. These weeds can drop plenty of seed. The importance of knowing which weed you have is more about the message they are trying to send you. These weeds can indicate other issues that may be part of the reason the grass is thinning and allowing the weeds to take over in the first place.
Common lespedeza is a legume. It thrives when water is plentiful and soil nutrients are low. If this is the weed “taking over” your yard, you need to get a soil test and evaluate your watering habits. Improving fertility and reducing soil moisture will naturally weaken common lespedeza.
If your thin patches of declining grass are being replaced with spurge, it may be time to submit a sample for a nematode assay. Research has shown that spurge is a weed that can thrive with high populations of nematodes. Turfgrass species are easily harmed by nematodes (microscopic roundworms that imbed into and on grass roots). If the assay indicates harmful population levels, unfortunately there are few options for reduction of the nematodes. However, several ornamental plants are tolerant. So, you may need to consider creating a landscape bed area rather than continuing to battle poor-looking grass.
Weeds can serve as indicators to soil conditions that may need to be addressed. Learning to identify weeds may teach you more than just their names.
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.
(arranged in threes) leaves with three oblong, smooth leaflets. Leaflets have parallel veins nearly at right angles to a prominent mid-vein. Its leaves have smooth edges and a short spur at the tip of each leaflet. Flowers appear in late summer with small pink to purple, single flowers found in leaf axils on most of the nodes of the main stems. As common lespedeza matures, the stems harden and become woody.
