Dollar Weed | Gardening in the Panhandle

Gardening in the Panhandle LIVE Program Summary: Weeds – February 4, 2021

by Mark Tancig | Feb 11, 2021

Gardeners worldwide and throughout time have bemoaned weeds. In Florida, we get to enjoy weeds all year long! Our February Gardening in the Panhandle (GIP) Live episode focused on weeds and weed control. Many homeowners are interested in ways to control weeds and UF/IFAS Extension and your local extension agents are here to help. The following is a summary of the topics we discussed and links for more research-based information on weeds.

What is a Weed?

Many folks come to the extension office holding a plant and ask, “Is this a weed”? Well, whether it is a weed or not is up to the individual, as the only definition for a weed is “a plant out of place”. Bermudagrass and Oxalis are good examples of plants that some try to grow while others try to kill. One person’s weed is another’s wildflower! However, to be clear, plants classified as invasive by UF/IFAS and governmental entities are officially weeds. There are resources to help identify several common plants that are generally considered weeds by most homeowners and landscapers.

Weed ID Links

Florida Weeds: https://sfyl.ifas.ufl.edu/lawn-and-garden/florida-weeds/
Edible Weeds: https://content.ces.ncsu.edu/extension-gardener-handbook/6-weeds
Identifying Weeds: Virginia Tech: https://weedid.cals.vt.edu/ and NC State: https://www.turffiles.ncsu.edu/weeds-in-turf/
Weeds of Southern Turfgrass: http://ifasbooks.ifas.ufl.edu/p-150-weeds-of-southern-turfgrasses.aspx

Common, and aggravating, weeds.

How to Prevent Weeds?

There are some general gardening practices that can help prevent weeds so there is less of a need to control them. A lawn that is healthy is less likely to be invaded by weeds and the use of mulch can greatly reduce weed growth in planting beds. Other practices, like the placement of weed fabrics/cloths are less effective and/or less practical in many garden situations.

Weed Prevention Links

Mulching Guidelines: https://ag.umass.edu/home-lawn-garden/fact-sheets/mulching-weed-management-in-urban-landscape
FYN Handbook – Principle #s 1, 2, 3, 4, 6: https://ffl.ifas.ufl.edu/materials/FYN_Handbook_2015_web.pdf
Consider Landscape Fabric Carefully: http://blogs.ifas.ufl.edu/escambiaco/2016/08/12/consider-landscape-fabric-carefully-2/

How to Control Weeds?

Once you know and/or decide that what you have is a weed and that it needs to be dealt with, then you have to consider your control options. Prevention, as mentioned above, is key but sometimes you may need to use other methods of control, such as physical, mechanical, and/or chemical means. With chemical weed control, it is important to always read and follow the product label.

Weed Control Links

Weed Management Guide for Florida Lawns: https://edis.ifas.ufl.edu/ep141
Weed Control in Planting Beds: https://edis.ifas.ufl.edu/ep523
Non-Chemical Weed Control: https://edis.ifas.ufl.edu/hs1170
Summer Annual Weed Control Timeline: https://sfyl.ifas.ufl.edu/media/sfylifasufledu/escambia/horticulture/Summer-Annual-Lawn-Weed-Control-Timeline.pdf
Winter Annual Weed Control Timeline: https://sfyl.ifas.ufl.edu/media/sfylifasufledu/escambia/horticulture/Winter-Annual-Lawn-Weed-Control-Timeline.pdf
Florida Homeowner Herbicide Guide: https://edis.ifas.ufl.edu/pdffiles/EP/EP57500.pdf
National Pesticide Information Center: http://npic.orst.edu/
Glyphosate Alternatives: https://edis.ifas.ufl.edu/ep580
Pesticide Use Around Pets: http://npic.orst.edu/health/pets.html

General dates of common annual weed emergence. Credit: Dr. Ramon Leon, UF/IFAS.

Specific Weed Recommendations

When managing pests, proper identification is key to effective control. Because some weeds are annuals, and present either during the cool or warm season, and others are perennials, proper weed identification can provide a more detailed control strategy. Use the weed ID links above and the document links below for more precise, and effective, weed management.

Species-Specific Control Links

Dandelion Control: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7469.html
Dollarweed Biology and Management: http://edis.ifas.ufl.edu/ep389
Doveweed Control: https://edis.ifas.ufl.edu/pdffiles/AG/AG39500.pdf
Johnsongrass ID and Control: https://edis.ifas.ufl.edu/ag372
Oxalis Control: https://edis.ifas.ufl.edu/ep514
Torpedograss Control: https://plants.ifas.ufl.edu/plant-directory/panicum-repens/

If you need additional assistance with weed control, please contact your local county extension office. Please tune in for future GIP LIVE episodes for more research-based information on gardening topics.

Dollarweed: Friend or Foe

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.