by Ray Bodrey | Feb 5, 2018
We have many weeds in the Panhandle that are a nuisance to our landscape, with some being very difficult to control. Dollarweed certainly falls into this category. But, does dollarweed have an upside?
Dollarweed (Hydrocotyle spp.) is a largeleaf creeping perennial that thrives in central and northern Florida, but is found throughout both Atlantic and Gulf coasts. Dollarweed is resilient, as it can reproduce by seed, rhizomes and tubers. The mature plant produces vertical shoots with shiny green round shaped leaves and scalloped edges. The leaves can grow up to the size of a silver dollar, hence the plant’s name. This plant grows low to the ground and thrives in moist environments.
Figure 1: Pennywort (Dollarweed) vs. Dicondra.
Credit: Ramon G. Leon, Darcy E. P. Telenko & J. Bryan Unruh, UF/IFAS
Hydrocotyle umbellate is the species most found in Florida lawns. In city landcsapes, dollarweed can be an indicator of leaking water mains or even septic drainfield problems. It also can be an indicator that you may be over-irrigating your lawn. Hydrocotyle bonarienies or pennywort, on the other hand, is a species that is found on frontal and back dune areas, along with sandy marsh or flatlands. This species is known to help stabilize dunes and assist in combatting dune erosion.
Often, dollarweed is confused with pony’s foot or Dicondra carolinensis. This weed will grow along with dollarweed, as it prefers moist environments as well. Pony’s foot has a distinct difference in leaf structure than dollarweed. Pony’s foot has a kidney-shaped circular leaf, as dollarweed is disc shaped.
How does one control dollarweed in a landscape? Pulling it up by hand can be successful. However, it’s a must to pull all of the white rhizomes from the soil. Otherwise, the plant will rebound quickly. Selective & non-selective herbicides will control dollarweed. However, you must be persistent. Applying a pre-emergent and post emergent herbicide is the best practice when using chemical applications. There are many herbicides on the market that specifically list the control of dollarweed, such as atrazine and 2, 4-D options. Always follow the directions and precautions from the manufacturer when using a herbicide and be sure that the product will not affect your variety of turfgrass. Contact your local county extension office for more information on controlling dollarweed and other pesky weeds.
Supporting information for this article can be found in the following the UF/IFAS publication:
“Pennywort (Dollarweed) Biology and Management in Turf” by Ramon G. Leon, Darcy E. P. Telenko and J. Bryan Unruh: http://edis.ifas.ufl.edu/pdffiles/EP/EP38900.pdf
& “Native Plants for Coastal Dune Restoration- What, When and How for Florida” by M.J. Williams, USDA NRCS: https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/flpmspu7474.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
by Matthew Orwat | Oct 10, 2017
Burweed, Soliva Sessilis. – Image Credit: Joseph M. DiTomaso, University of California – Davis, Bugwood.org. Creative Commons License
On the top of my list of lawn related annoyances is stepping into a patch of burweed, Soliva sessilis, which is in the sunflower family and is also known as spurweed. The leaves are opposite along the stem and sometimes resemble parsley. The main ways in which burweed can irk the casual gardener are sticking to socks, sneaking in with the dog, or littering flower beds with its nuisance. It can also hide in the house and reappear when shoes are removed. This causes pain in both the foot and the ear.
Lawn burweed has been an especially noticeable problem in lawns. Over the years, extension offices throughout Northwest Florida have been fielding many questions and finding solutions to lawn burweed infestations!
Maintaining a healthy vigorous lawn will prevent weeds from taking over. If your lawn is reasonably healthy and only a few instances of this weed exist, try to mechanically remove them and encourage the lawn to outgrow them.
If an infestation of burweed occurred last year on a specific patch of turf, take note. The best time to apply pre-emergent herbicides to control burweed is in October, when nighttime temperatures drop to between 55-60 degrees F for a few consecutive nights. A widely used pre-emergence product for burweed control is isoxaben, which is sold under the brand name of Gallery as well as others. It prevents the weed from emerging from the ground when it germinates and can be used on St. Augustine, centipede, bahia and zoysia lawns, as well as in ornamental shrub beds. In northwest Florida, this herbicide needs to be applied in October for best results. A second application later in the season might be warranted. For more information about control, please consult this excellent article on lawn burweed management.
Now is the time to control burweed before it gets started. As temperatures cool burweed seed will germinate, as it is a winter annual. In cases where it is already coming up, control with post-emergent herbicide may be warranted.
The active ingredients mentioned above are present in a variety of ‘trade name’ products* available from your local garden center, farm supply or co-op. Be sure to read label instructions carefully and contact your local extension office for any assistance. I hope all the northwest Florida lawn managers prevent burweed this fall so that lawns will be burweed free next spring.
Happy Gardening!
by Daniel J. Leonard | May 18, 2017
If you’re like me, growing turfgrass is often more of a hassle than anything else. Regardless of the species you plant, none tolerates shade well and it can seem like there is a never-ending list of chores and expenses that accompany lawn grass: mowing (at least one a week during the summer), fertilizing, and constantly battling weeds, disease and bugs. Wouldn’t it be nice if there were an acceptable alternative, at least for the parts of the lawn that get a little less foot traffic or are shady? Turns out there is! Enter the wonderful world of perennial groundcovers!
Perennial groundcovers are just that, plants that are either evergreen or herbaceous (killed to the ground by frost, similar to turfgrass) and are aggressive enough to cover the ground quickly. Once established, these solid masses of stylish, easy to grow plants serve many of the same functions traditional turf lawns do without all the hassle: choke out weeds, provide pleasing aesthetics, reduce erosion and runoff, and provide a habitat for beneficial insects and wildlife.
The two most common turfgrass replacements found in Northwest Florida are Ornamental Perennial Peanut (Arachis glabra) and Asiatic Jasmine (Trachelospermum asiaticum); though a native species of Mimosa (Mimosa strigillosa) is gaining popularity also. All of these plants are outstanding groundcovers but each fills a specific niche in the landscape.
Perennial Peanut Lawn
Perennial Peanut is a beautiful, aggressive groundcover that spreads through underground rhizomes and possesses showy yellow flowers throughout the year; the show stops only in the coldest winters when the plant is burned back to the ground by frost. It thrives in sunny, well-drained soils, needs no supplemental irrigation once established and because it is a legume, requires little to no supplemental fertilizer. It even thrives in coastal areas that are subject to periodic salt spray! If Perennial Peanut ever begins to look a little unkempt, a quick mowing at 3-4” will enhance its appearance.
Asiatic Jasmine
Asiatic Jasmine is a superb, vining groundcover option for areas that receive partial to full shade, though it will tolerate full sun. This evergreen plant sports glossy dark green foliage and is extremely aggressive (lending itself to very rapid establishment). Though not as vigorous a climber as its more well-known cousin Confederate Jasmine (Trachelospermum jasminoides), Asiatic Jasmine will eventually begin to slowly climb trees and other structures once it is fully established; this habit is easily controlled with infrequent pruning. Do not look for flowers on this vining groundcover however, as it does not initiate the bloom cycle unless allowed to climb.
Sunshine Mimosa
For those that prefer an all-native landscape, Sunshine Mimosa (Mimosa strigillosa), also known as Sensitive Plant, is a fantastic groundcover option for full-sun situations. This herbaceous perennial is very striking in flower, sending up bright pink, fiber-optic like blooms about 6” above the foliage all summer long! Sunshine Mimosa, like Perennial Peanut, is a legume so fertility needs are very low. It is also exceptionally drought tolerant and thrives in the deepest sands. If there is a dry problem spot in your lawn that receives full sun, you can’t go wrong with this one!
As a rule, the method of establishing groundcovers as turfgrass replacements takes a bit longer than with laying sod, which allows for an “instant” lawn. With groundcovers, sprigging containerized plants is most common as this is how the majority of these species are grown in production nurseries. This process involves planting the containerized sprigs on a grid in the planting area no more than 12” apart. The sprigs may be planted closer together (8”-10”) if more rapid establishment is desired.
During the establishment phase, weed control is critical to ensure proper development of the groundcover. The first step to reduce competitive weeds is to clean the site thoroughly before planting with a non-selective herbicide such as Glyphosate. After planting, grassy weeds may be treated with one of the selective herbicides Fusilade, Poast, Select, or Prism. Unfortunately, there are not any chemical treatments for broadleaf weed control in ornamental groundcovers but these can be managed by mowing or hand pulling and will eventually be choked out by the groundcover.
If you are tired of the turfgrass life and want some relief, try an ornamental groundcover instead! They are low-maintenance, cost effective, and very attractive! Happy gardening and as always, contact your local UF/IFAS County Extension Office for more information about this topic!
by Sheila Dunning | Feb 3, 2017
Remember last summer? The hot, dry days. Grass drying up and turning brown. Yet, the weeds are green and doing fine. However, every herbicide label warns against applying when the temperatures are above 85 degrees and especially under drought conditions. Those weeds flourished and dispersed seed everywhere. Now, they are just sitting there ready to sprout again.
It’s time to start thinking about weed prevention. Pre-emergent herbicides need to be applied prior to seed germination. Late winter is the time to focus on summer annual weeds. The narrow window of application is challenging. Homeowners often wait too late into spring to put out preventative products. A general rule of thumb for pre-emergent herbicide timing is February 15 – March 1 in North Florida.
However, weed seeds germinate in response to soil temperature, not calendar dates. By monitoring day time temperatures, one can determine a more effective application date. When there are 4-5 consecutive days that reach 65 to 70 degrees weeds will germinate. This generally coincides with the first blooms appearing on azaleas and dogwood. With a warm winter it may occur as early as mid-January.
Some of the active ingredients in pre-emergent herbicides include dithiopyr, isoxaben, oryzalin, pendimethalin, prodiamine and simazine. Always read the label for specific weed controlled and observe all directions, restrictions and precautions.
Weed and feed products that contain nitrogen are not suitable as pre-emergent herbicides. Irrigation before and after application is necessary to activate these products. The chemical binds to soil particles, creating a barrier that remains effective for 6-12 weeks. Reapplication will be necessary for season long control, especially with constantly fluctuating winter temperatures. Now is the time to purchase pre-emergent herbicides and prepare to apply them. For more information on weed control in lawns go to: http://edis.ifas.ufl.edu/ep141
by Beth Bolles | Jan 17, 2017
It won’t be long before homeowners start thinking about sodding a new lawn or renovating areas of their existing turf. Although sodding when turf is dormant is acceptable, it is best to install sod that is green. One reason is that you can see if any sod pieces are infested with weeds such as bermudagrass . This perennial grass is very difficult to manage once it becomes established in centipede, St. Augustine, or zoysiagrass. Always remove turf pieces with bermudagrass during the installation process to prevent it from taking over a patch of your new lawn.
Bermudagrass growing in a piece of centipede sod. This piece should have been removed during installation to prevent the bermudagrass from taking over a patch of new centipede lawn. Photo by Beth Bolles, UFAS IFAS Escambia County Extension
If you have a piece of turf or a small area where common bermudagrass has emerged in your desirable grass, take care of the issue as soon as it is seen. The best option is dig out the infested area making sure that you get the underground runners of the bermudagrass. Smooth out the bare soil and then install new sod pieces. You may have to hand water these pieces as needed since the surrounding turf will already be established.
by Les Harrison | Aug 23, 2016
Air potato leaf beetle. Photo credit: Les Harrison, UF/IFAS.
A small, but brightly colored beetle has appeared in north Florida: the air potato leaf beetle (Liliocetis cheni), a native of East Asia. The beetle, less than half an inch long, has a candy apple red body that stands out against green leaves and the more muted earth tones of most other bugs. The striking bright glossy red coating would be the envy of any sports car owner or fire truck driver.
Unlike other arrivals to the U.S., this insect was deliberately released in 2012 for biological control of air potato. After years of testing, approval was finally given to release air potato leaf beetles to begin their foraging campaign against this invasive plant species. The beetle has very specific dietary requirements and only can complete its life cycle on air potato. The larvae and adults of this species consume the leaf tissue and occasionally feed on the tubers.
When a population of air potato leaf beetles finish off an air potato thicket, they go in search of nourishment from the next patch of air potato. They are sometimes seen during stopovers while in search of their next meal.
Air potato (Dioscorea bulbifera) is an herbaceous perennial vine which is easily capable of exceeding 60 feet in length. It quickly will climb over any plant, tree or structure unfortunate enough to be in its vicinity. The vine also produces copious quantities of potato-like tubers suspended from its vines. Unless collected and destroyed, most of the easily camouflaged potatoes will germinate and intensify the infestation.
Air potato. UF/IFAS Photo: Thomas Wright.
Air potato came to Florida in 1905 from China and quickly escaped into the wild. By the 1980’s it was a serious pest species in south and central Florida, but has gradually become established in the panhandle, too. Chemical control of the air potato has been difficult. Repeated herbicide treatments are required to kill a thicket with multiple plants.
Unlike the air potato leaf beetle that only eats air potato, kudzu bugs eat their namesake vine (kudzu), but also feed on a number of other plants including a wide selection of valuable legumes and be quite destructive. Kudzu bugs were accidently introduced in north Georgia in 2009 and have spread across the south in the ensuing years and become established in north Florida.
It is a pleasant surprise to know air potato leaf beetles are working to limit the invasive air potato vine, but it is sad to think there is plenty more for them to eat.
To learn more about the air potato and the beetle:
Natural Area Weeds: Air Potato (Dioscorea bulbifera)
Air Potato Leaf Beetle Publication
