by Daniel J. Leonard | Jul 22, 2021
If you’ve taken care of your yard properly from spring green-up to now (mid-July), you might think you can comfortably coast into the cool temperatures of fall without any problems. You would be mostly right, save for one extraordinarily tough weed that waits until the depths of summer to rear its troublesome head: Doveweed (Murdania nudiflora).
Doveweed seedlings just emerged on July 9, 2021. Photo courtesy of Daniel Leonard.
Doveweed is an insidious invader of Panhandle lawns. In the Panhandle, Doveweed germinates (sprouts) long after most other summer annual weeds, from late May-June when soil temperatures reach ~70°F. This allows it to sneakily avoid spring pre-emergent herbicide applications and even early summer post-emergent applications that target common weeds like Florida Pusley, Spurge species, and others. Doveweed also looks an awful lot like many of our common lawn turfgrasses, especially Centipede and St. Augustine Grass. It possesses thick, shiny, grass-like foliage and even grows in a spreading, low to the ground fashion. This mimicry causes many homeowners to not realize there is a problem until it’s too late. Once Doveweed is mature and displaying its characteristic purple flowers, it is very difficult to control. Finally, Doveweed is extremely tough and aggressive, particularly thriving in moist areas of the lawn. In these areas, Doveweed can easily outcompete the desirable turfgrass and, without intervention by you, will soon have the whole lawn to itself.
Controlling Doveweed is no easy task and requires a combination of practices to keep it out of your lawn. The first line of defense against any weed, Doveweed included, is through proper cultural practices. In turfgrass lawns, this means ensuring that you mow your lawn regularly and at the proper height (2.5” or so for Centipedegrass), keeping the lawn irrigated during droughty periods, fertilizing based on a soil test, etc. Being diligent in the above tasks will go a long way to ensuring that your turfgrass is healthy and better able to ward off a Doveweed invasion. However, even when homeowners maintain their turf perfectly, chemical herbicides are usually required to keep Doveweed at bay.
Doveweed patch in St. Augustine Sod.
While many commonly used homeowner herbicides are not effective on Doveweed, there are several quality options at your disposal.
- Doveweed is most easily controlled with preemergent herbicides, specifically one of the following: Atrazine, Pennant Magnum (S-metolachlor), Tower (dimethenamid), and Specticle (indaziflam). The issue with pre-emergents is that most folks shelve them after spring application in February or March. Since these products lose their efficacy after 4-6 weeks, Doveweed’s emergence in May is undeterred. To obtain control on Doveweed with these products, split the spring application and apply once in late Feb/early March and again in mid-late April.
- Doveweed can also be controlled by post-emergent herbicides after it is up and growing, though multiple applications may be required. The most effective formulations contain a combination of 2,4-D or Dicamba and other herbicides. While most of these products have at least fair efficacy on Doveweed, stronger, more expensive products like Celsius, Tribute Total and others provide better results.
- If Doveweed has already displaced turfgrass in large areas of your lawn, you may unfortunately be better off to make an application of a non-selective herbicide like glyphosate (Roundup), kill out the entire area of infestation and start over by resodding.
While Doveweed is a major problem in Panhandle lawns, it doesn’t have to be in yours! By keeping your turf healthy with proper cultural practices and making timely applications with effective herbicides, your lawn can be a Doveweed free zone! For assistance in Doveweed identification in your lawn, help choosing herbicides and calculating application rates, or any other horticultural information, contact us at the UF/IFAS Calhoun County Extension office! Happy Gardening!
by Sheila Dunning | Jul 15, 2021
Photo by Dr. Steve Johnson
Treefrog calls are often heard with each rain event. But, how about a “snoring raspy” call that begins after a day time light rain? That may be a male Cuban treefrog trying to attract the girls. Cuban treefrogs breed predominately in the spring and summer. Reproduction is largely stimulated by rainfall, especially warm summer rains such as those associated with tropical weather systems and intense thunderstorms.
Range of Cuban treefrogs
The Cuban treefrog, Osteopilus septentrionalis, was accidently introduced to Florida in the 1920’s as a stowaway in shipping crates from the Caribbean. Over the last hundred years, the invasive frog has managed to spread throughout Florida and the Southeastern U.S. by hitchhiking on ornamental plants, motorized vehicles, and boats. Though occasional cold winters have created temporary population setbacks, new generations of Cuban treefrogs continue to be reported in north Florida, including the Panhandle.
An invasive species is generally defined as a plant, animal or microbe that is found outside of its native range, where it negatively impacts the ecology, economy or quality of human life. Cuban treefrogs come out at night to feed on snails, millipedes, spiders and a vast array of insects. But, they are also predators of several Florida native frogs, lizards and snakes. Tadpoles of the invasive Cuban treefrog have been shown to inhibit the growth and development of native Southern toad and green treefrog tadpoles when all of the species are in the same water body. Additionally, a large female Cuban treefrog can lay over 10,000 eggs per season in very small amounts of water.
Panhandle citizens can help manage the invasive Cuban treefrog by learning to identify them and reduce their numbers. All treefrogs have expanded pads on the ends of their toes. Cuban treefrogs have exceptionally large toepads. They also have a “big eyed” appearance due to their oversized bulging eyes. Cuban treefrogs may exceed 6 inches in length, have warty-looking skin with possible blotches, bands or stripes, and vary greatly in color. However, they can be distinguished from other treefrogs. Cuban treefrogs have a yellowish wash where their front and rear legs are attached to their body. Juvenile Cuban treefrogs have red eyes and blue bones visible through the skin of their hind legs. The skin of the Cuban treefrog produces a sticky secretion that can cause a burning or itching sensation if it contacts the eyes or nose of certain individuals. It is recommended to wear gloves and wash your hands after handling Cuban treefrogs.
It is important to document the locations of Cuban treefrogs in the Panhandle. By placing short sections of PVC pipe in the ground around your home and garden will provide hiding places for treefrogs that enables you to monitor for Cuban treefrogs. Cut 10 foot sections of 1.5-inch-diameter PVC pipe into approximately three-foot-long sections and push them into the ground about 3-4 inches. To remove a frog from a pipe, place a clear sandwich bag over the top end, pull the pipe from the ground, and insert a dowel rod in the other end to scare the frog into the baggie. If you suspect you have seen one, take a picture and send it to Dr. Steve Johnson at tadpole@ufl.edu. Include your name, date, and location. Dr. Johnson can verify the identity. If it is a Cuban treefrog, upload the information by going to http://www.eddmaps.org/ and click the “Report Sightings” tab.
Once identified as a Cuban treefrog, it should be euthanized humanly. To do that, the Cuban treefrog in a plastic sandwich bag can be placed into the refrigerator for 3-4 hours then transferred to the freezer for an additional 24 hours. Alternatively, a 1-inch stripe benzocaine-containing ointment (like Orajel) to the frog’s back to chemically anesthetize it before placing it into a freezer. After freezing, remove the bagged frog from the freezer and dispose of in the trash. Ornamental ponds should also be monitored for Cuban treefrog egg masses especially after a heavy rain. The morning after a rain, use a small-mesh aquarium net to scoop out masses of eggs floating on the surface of the pond and simply discard them on the ground to dry out. Various objects that can collect water found throughout your yard need to be dumped out regularly to reduce breeding spots for both Cuban treefrogs and mosquitoes.
by Daniel J. Leonard | Jun 24, 2021
Nutsedge, commonly called “nutgrass”, is one of the most important and difficult to control weed pests in the world. Found in nearly every growing situation, from crop fields and vegetable gardens to landscapes and turfgrass lawns, I bet every person reading this has contended with controlling nutsedge at some point! Nutsedge (a common term to describe several species of weeds in the genus Cyperus) not only reduces curb appeal, but also h as a detrimental effect on desirable plantings around it. Because of its aggressive nature and dense root system, it competes heavily with “good” plants for water, light, and nutrients, causing the plants we are trying to grow to suffer. This is a weed that you definitely do not want in your lawn or landscape!
To keep nutsedge at bay, it’s important to know a few facts about it. First, “nutgrass” is not a grass at all, but a totally different class of plants known as sedges. This is important because selective herbicides used to kill grassy weeds will not affect nutsedge. Though they’re grass look-alikes, sedges can be distinguished by their distinctive triangular shaped stems. You can actually feel the three edges of nutsedge stems. If ever in doubt over whether a weed is a grass or a sedge, remember “sedges have edges”. Most sedges are perennials, dying back to the ground each year in winter and reemerging from tubers, called “nutlets”, that can survive over a foot under the ground! Also, while sedges generally prefer wet areas, they aren’t very particular about where they grow and are equally at home in sand or clay, wet or dry, and sun or shade. All these characteristics make sedges hard to control and cause much consternation amongst gardeners!
The first line of defense in controlling nutsedge is keeping a dense cover over any bare ground. In lawns, this means maintaining a thick, healthy turf as weeds love to enter lawns through thin or patchy areas. This can be accomplished by mowing regularly, fertilizing appropriately based on a soil test, not overirrigating while also not allowing the grass to suffer badly during droughty periods. Easier said than done. In landscape beds, preventative control is a little easier. First, as nutsedge prefers wet areas, only irrigate when it is needed. During much of the year, most established landscapes can get by on rainfall alone. Next, simply maintain a roughly 3” layer of pine straw, wood chips, pine bark, or other natural mulch of your choice. Doing so will reduce all manner of weeds, nutsedge included, and is generally beneficial for ornamental plants as well! I do not recommend landscape fabric as it is a pain to install and remove and is not extremely effective at reducing nutsedge as the sedge’s sharp growing points punch right through most plastic or fabric mulches.
Though mulching and other preventative measures can reduce nutsedge numbers, those methods alone are usually not enough and chemical herbicides are required. Fortunately, in Panhandle lawns and landscapes, there are several excellent, readily available options for sedge control: imazaquin and halosulfuron.
- Imazaquin is the active ingredient in the common product Image Kills Nutsedge and has good activity on most sedge species. It can be applied safely to all the common turfgrass species grown in the area and can even be sprayed right over the top of most common ornamental landscape plants!
- Halosulfuron is the active ingredient in the product Sedgehammer (available online or at specialty landscape supply stores) and several other generic products. Halosulfuron products provide excellent control of all nutsedge species and are safe to use in all turfgrass species found in Florida. While most landscape plants are tolerant of halosulfuron application, use care and try to only spray it on sedge weeds to avoid any unwanted yellowing or damage.
While both products begin working immediately, it may take several weeks to see sedge weeds start suffering and patience is necessary! Though both products are effective, follow up applications 3-4 weeks later are generally necessary to clean up any surviving sedge.
Nutsedge is a nasty little weed that can be difficult, though not impossible to manage. Through some smart cultural practices and timely applications of either imazaquin or halosulfuron, you can keep your lawn and landscapes nutsedge free! For more information about nutsedge control on your property or any other agricultural or horticultural topic, contact your local UF/IFAS County Extension office! Happy Gardening!
by Pat Williams | May 27, 2021
Our Gardening in the Panhandle blogs cover many horticultural topics concerning yards, however let us not forget about properties that contain a body of water (pond, lake, retention or detention basin, stream, river or Gulf of Mexico). Out of the nine Florida-Friendly Landscaping™ principles, five directly deal with water quality. Those principles are #2 Water Efficiently, #3 Fertilize Appropriately, #6 Manage Yard Pests Responsibly, #8 Prevent Stormwater Runoff, and #9 Protect the Waterfront. An easy argument can be made that the remaining four principles (#1 Right Plant, Right Place, #4 Mulch, #5 Attract Wildlife, and #7 Recycle) can also impact water quality on your properties.
Photo Credit: University of Florida/IFAS Extension
The quickest and easiest way to start improving water quality is setting up a maintenance-free zone along your shore. At minimum, you should keep all chemicals 10′ away from the water’s edge and increase that distance as your slope becomes steeper. Chemicals include all fertilizers (#3) and any pesticides/herbicides (#6) meant for the landscape (there are times when situations arise where treatment of the water is warranted). If you must fertilize up slope, make sure to reduce irrigation (#2) to about 25% of normal the first time which keeps the fertilizer from dissolving and running down your slope’s surface (#9).
Cascades Park in Tallahassee, FL.
If possible replace turfgrass with a no mow zone containing plants adapted for shorelines to prevent applications of fertilizer and chemicals. Plants (#1) other than turfgrass will have deeper roots, stabilize the bank better and absorb more chemicals before entering the water. These taller plants in turn can become habitats (#5) for birds and other specimens which can increase your ecosystem’s biodiversity. Some properties have collection swales or low lying areas where water pools and then flows into the water. It is best to understand how water flows through the property and reduce chemicals in those areas too (#8).
Heavy rains caused water levels to raise around this pond and decomposing leaf litter added a film over the pond.
As gardeners, we tend to compost our leaves and yard debris (#7) plus use mulch (#4) to reduce water loss from our soils. Keep mulches and compost piles away from flood zones and when possible keep leaves from washing into your water as they can create films on the surface. Never allow grass clippings to land on water surfaces as they will add nutrients when tissue decays.
As Florida continues to grow, we all must play an important role in keeping our water clean and safe for us, animals, birds, and aquatic life. If you have questions on improving your water quality, please contact your local county Extension Agent or Water Regional Specialized Agent (RSA). For additional information visit these other sites.
Protecting Florida’s Water Resources: https://gardeningsolutions.ifas.ufl.edu/care/florida-friendly-landscapes/floridas-water-resources.html
Living on Water’s Edge: http://www.sarasota.wateratlas.usf.edu/upload/documents/LivingontheWatersEdgeFreshwater.pdf
Urban Fertilizer Ordinances in the Context of Environmental Horticulture and Water Quality Extension Programs: Frequently Asked Questions: https://edis.ifas.ufl.edu/publication/AE534
by Daniel J. Leonard | Apr 22, 2021
With the traditional planting date of Good Friday behind us, the home tomato gardening season in the Panhandle is in full swing. While tomatoes are the most persnickety veggie we grow, there are several practices you can adopt to help you succeed: selecting an adapted variety; regularly scouting for insects and disease; and watering and fertilizing appropriately. However, the most overlooked practice for success gardeners can adopt is proper pruning.
‘Big Beef’ Tomato with lower leaves removed. This is an excellent disease reduction practice. Photo courtesy of Daniel Leonard.
Correct pruning does a couple of positive things for tomatoes. First, it reduces the incidence of disease by preventing leaf contact with the soil, opening the interior of the plant, and allowing better airflow. This is important as many plant pathogens reside in the soil and only need a splash of water to travel onto plant leaves. Also, densely foliaged plants trap warm, moist air in their canopies, creating a perfect environment for disease to flourish. Letting the plant canopy “breathe” through pruning prevents that negative environment from forming! Second, correct pruning of “suckers” (extra growth points that can develop into shoots) helps tomato plants develop optimum yield and fruit quality. By removing suckers, more water, nutrients, airflow, and light are directed to the main stems, where the majority of tomato fruit production occurs. Failing to remove suckers (especially on indeterminate varieties) can result in reduced yields, increased disease, and generally messy plants!
With the reasons for pruning tomatoes established, the next step is learning exactly what to prune and how to do it in a sanitary matter.
- Get rid of any foliage that could encounter the soil, generally all leaves occurring on the lower 12-16″ of the plant. All kinds of nasty tomato destroying diseases, like Early Blight and Bacterial Leaf Spot, reside in the soil and are just waiting to be splashed onto your plants – don’t let that happen.
- Determine how many primary shoots you want your plant to have. Leave enough lower suckers to achieve that number (generally just one, two, or three as more than 3 primary stems gets hard to manage), and prune or pinch out all the rest. To prevent stress from pruning, be diligent in removing suckers when they are still small, 2” or less.
- Always clean and disinfect your pruners before making a cut on a tomato plant. This is best accomplished by rinsing the blades with warm soapy water, drying, and following with by a quick alcohol spray. A 10% bleach solution will also work, but if not thoroughly rinsed after, bleach can corrode pruner blades and other working parts. If you make cuts on a plant that appears diseased, repeat the sanitizing process before you begin pruning another plant as “dirty” pruners are an easy way to spread pathogens in the garden.
Developing vegetative “sucker” that will need to be removed. Photo courtesy of Daniel Leonard.
While tomatoes are indeed a difficult vegetable to grow, learning to prune them correctly will greatly help to make this a successful season. If you just keep leaves off the ground, suckers pinched, and pruners cleaned, you’ll be well on your way to less disease, prettier plants, and more tomatoes to pick. For more information on growing tomatoes and any other horticultural topic, please contact your local UF/IFAS County Extension office. Happy Gardening!
