Just when you think your battle against weeds is over for the summer, cooler nighttime temperatures and shorter days spark the beginning of a new crop of your least favorite plants. The question of many homeowners is how did all the weeds get to my landscape?
There are many ways that weeds make it to the landscape. They can be brought in with new soil, mulch, container plants, dropped by birds, delivered on the fur of animals, carried by wind, or on the deck of a lawn mower. If that is not enough to depress you than also realize that regardless of outside sources of weeds, your landscape already has plenty onsite that you don’t even know about.
The deck of a lawn mower can collect plant debris, including seeds, that are spread through the landscape. Photo by Beth Bolles, UF IFAS Extension Escambia County.
In the soil, there is a large number of weed seeds ready to germinate when the conditions are just right. Understanding how your common landscape practices can encourage or discourage the germination of these seeds, can help you begin to manage some weed infestations.
Many of the seeds of common annual weeds are very small. They require exposure to sunlight in addition to the proper temperatures and moisture to germinate. Sunlight is critical though and seeds will not germinate without adequate sunlight. If the small seeds are deep in the soil, you will probably never know they are there. When you turn soil or disturb soil such as when installing plants, you bring the small seeds close to the surface and closer to light. They can then be stimulated to germinate. The next thing you know is that you have an area covered in weed seedlings.
What does this mean for your gardening practices? Try your best to block sunlight from hitting exposed soil. You can do this by keeping a healthy turf, free of thinning spaces. A 2-3 inch layer of mulch in plant beds and vegetable gardens will reduce weed seed germination. Finally when you are installing plants in an established bed, try not to mix soil with surrounding mulch. Seeds will easily germinate within the mulch if it becomes mixed with soil.
It is inevitable that your landscape will have some weeds but a few easy gardening practices can reduce some of your weed frustrations.
Figure 1: Chamberbitter, a common annual weed.
Credit: Mary Salinas, UF/IFAS Extension Santa Rosa County.
With daily rainfall occurring regularly, coupled with humid temperatures, summer annual weeds have had a mighty boost in growth. Chamberbitter, Florida pusley, sedge and oxalis are just some examples of the many weeds that are exploding across our landscape.
Chamberbitter (Phyllanthus urinaria) is found as north as Illinois and as west as Texas, but thrives in lower southeastern states. It’s a headache for homeowners as well as pasture managers. The foliage resembles that of the mimosa tree (Albizia julibrissin) and can be confused with the native mimosa groundcover, known as powderpuff mimosa (Mimosa strigillosa). This plant grows upright and develops a long taproot. Wart-like seeds can be found on the underside of the branch.
Florida Pusley (Richardia scabra L.) also known as Florida snow or Mexican clover, has recently blanketed landscapes in the Panhandle with white flowers. It’s a persistent weed that moves quickly.
Sedges and sedge-like plants (Cyperus ssp.), known as kyllinga, are species that emerge in late spring and thrive in summer months in warm, moist climates. Excessive irrigation or areas with poor drainage create a very hospitable environment for these weeds. Sedges are annual grass-like plants have an elaborate flower-bearing stems. Yellow and purple nutsedge are the most common species. Kyllingas have smaller leaves and are less vertical. Sedges and kyllingas are fast spreading, and reproduce through seed and rhizomes, or underground tubers.
Oxalis or yellow woodsorrel (Oxalis stricta) have heart-shaped lobes and have a bright yellow flower. Oxalis reproduces by seed and have a narrow “okra-like” seed pod.
Figure 1: (L to R) Chamberbitter, Pusley, Sedge, Kyllinga & Oxalis.
Credit: Stephen H. Brown, UF/IFAS Extension Lee County
What about control? Some cultural control methods are hand removal and mowing frequently to offset the life cycle, but these practices alone will most likely not solve the problem. There are many broad spectrum herbicides that can be used to control these weeds with good results, but you must be persistent. Some are season long applied products. However, most effective products need to be applied in cooler temps than we have now. Consecutive days of temperatures of less than 90 degrees would be optimal. Applying the chemical otherwise will most likely harm the turfgrass. Be aware, some productions will injure or kill centipede and St. Augustine, but are safe to use on other turfgrasses like bermuda, bahia and zoysia. Be sure to read the label and follow the directions and precautions.
Another option is non-selective herbicides, like glyphosate, which can be used in thick patches or for spot treatment. When using a selective herbicide, remember to protect turfgrass and other plants from spray drift or any contact, especially regarding ornamental plants and trees.
Contact your local county extension office for more information.
Supporting information for this article is from the following online publications:
Clemson Cooperative Extension publication: “Chamberbitter”, Bulletin HCIC 2314: http://www.clemson.edu/extension/hgic/pests/pdf/hgic2314.pdf
UT Institute of Agriculture document, “Nutsedge and Kyllinga Species” by Mathew T. Elmore, James T. Brosnan and Gregory K. Breeden: http://www.tennesseeturfgrassweeds.org/Lists/Fact%20Sheets/Attachments/23/W260updated2015.pdf
UF/IFAS EDIS publications: “Yellow Woodsorrel (Oxalis) Biology and Management in Turf” by J. Bryan Unruh, Ramon G. Leon, and Darcy E. P. Telenko: http://edis.ifas.ufl.edu/pdffiles/EP/EP38500.pdf
“Weed Management Guide for Florida Lawns” by J. Bryan Unruh, Ramon G. Leon, Barry J. Brecke, and Laurie E. Trenholm: http://edis.ifas.ufl.edu/pdffiles/EP/EP14100.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
Dr. Steve Johnson, UF/IFAS Associate Professor of Wildlife Ecology will be the featured speaker on June 6th
June 6th is a great day to learn about all types of invasive species that threaten natural areas in Northwest Florida!
The UF/IFAS Extension Bay County office will have multiple educational exhibits with living samples of species of concern from 9 a.m. – 5 p.m. on Wednesday, June 6th. This is a multi-agency effort to inform citizens about the impact of invasive plants and animals and how they can help reduce introduction and spread. For full details see the Bay_Invasive Workshop Flyer
We are pleased to announce our partners Florida Fish and Wildlife Conservation Commission (FWC) and Science and Discovery Center of Northwest Florida will be on hand to share information about caring for exotic pets and current management plans for invasive species such as Lionfish, Aquatic Weeds, and how to surrender an animal on designated Pet Amnesty Days.
At noon there will be a special guest speaker for a bring your own lunch & learn “Exotic Invaders: Reptiles and Amphibians of Concern in NW FL.” Dr. Steven Johnson, UF/IFAS Associate Professor of Wildlife Ecology, will talk about exotic reptiles and amphibians we should be aware of that may occur in our area.
In the morning, we will be focusing on the invasive air potato vine with the distribution of air potato leaf beetles for biological control. Need air potato leaf beetles to manage the air potato vine on your property? Please register here http://bit.ly/bayairpotato to receive beetles – they will be distributed from 9 a.m. – noon on June 6th.
Learn more about the success of the Air Potato Biological Control program at http://bcrcl.ifas.ufl.edu/airpotatobiologicalcontrol.shtml
Figure 1: Florida Betony, Stachys floridana. Credit: UF/IFAS Range Cattle Research & Education Center.
If you look closely at your yard, there is a good chance that you will find a plant that, depending on who you ask, is considered either a native wildflower or a weed and there are more than a few species that fit this description. If, upon even closer inspection, you find a plant with root tubers that resemble egg casings or even a rattlesnake’s rattle, you’ve stumbled upon Florida Betony.
Stachys floridana is a perennial broadleaf commonly referred to as rattlesnake weed due to it’s fleshy, white, segmented underground tubers. The plant has an erect stem with leaves that are opposite, shovel-shaped and coarsely serrated. The plant structure is very similar to mint. Flowers, emerging in late spring, are pinkish-purple in color. These inflorescences will also produce fruit, consisting of four nutlets. However, reproduction of the plant and it’s propensity to spread through lawns and gardens primarily occurs through dense root tuber development. Florida Betony’s growing range was originally confined to the state of Florida, but the commercial nursery trade played a major hand in dispersing the plant across the Southeast in the mid-1900’s. It can now be found as far west as Texas and as far north as North Carolina.
Figure 2: Tubers of the Florida Betony. Credit: Jill Bebee, UF/IFAS Gulf County Master Gardener.It can now be found as far west as Texas and as far north as North Carolina.
This time of year is when Florida Betony thrives. The moderate temperatures of fall and spring are the prime growing periods for Betony. In the heat of the summer, the above-ground structure of the plant will struggle and often disappear completely, only to reemerge in the fall. As a lawn weed, managing tuber development is key to controlling this plant. Applying herbicide to the leaves and stalk may seem at first to have conquered the weed. However, in most cases the tuber will simply regenerate. Glyphosate (Roundup) can be used effectively for control in ornamental plant beds where no turf is present. Be careful when spraying herbicides around trees, shrubs and other desirable plants as any foliar contact will cause phytotoxicity. If you have an infestation of Florida Betony in your turfed areas, there are a few options for control. Regular applications of three way broadleaf herbicides, such as mixtures of 2-4D, Dicamba and Mecoprop, are effective at suppressing this pesky plant. For more information and options, please contact your local county extension office or see the supporting information links below. Always refer to the product label for specific uses, precautions and application rates when using any herbicide.
Supporting information for this article can be found in the following the UF/IFAS EDIS publication, “Florida Betony Biology and Management in Turf” by J. Bryan Unruh, Ramon G. Leon, and Darcy E. P. Telenko: http://edis.ifas.ufl.edu/pdffiles/EP/EP38800.pdf
Spring 2018 is barely out of the starting gate. All kinds of plants are sprouting and producing blooms! This week’s last gasp of winter temperatures slowed the progress, but only slightly.
Much like the Easter egg hunts a few weeks ago, a search of the landscape can bring multiple surprises. Two colorful plants, spiderwort and rustweed, which are growing in the region fit into this category.
Tradescantia ohiensis, the scientific name for spiderwort, is a herbaceous native plant. Its most striking feature which makes it easily identifiable is the cluster of bright purplish-blue blooms which are currently on display.
Spiderwort in full flower. Image Credit Les Harrison
To the casual listener, the name spiderwort implies an arachnid with a complexion issue. Far from it, but the terminology is shrouded in agriculture and horticulture history.
The term wort, in its various forms, can be traced back to northern Europe to well over 1,000 years ago. Its meaning related at first to herbs, and then to plants without bark or hard stems.
It should not be confused with wart, a skin eruption relating to a virus. Contact with any part of the spiderwort does not infect a person with warts.
The spider part of the name relates to the flower peddles. In harsh sunlight of the afternoon, the Spiderwort’s peddles are reduced to fine threads similar to a spider’s web.
Spiderworts are often seen along fencerows, in pastures and untended fields, and it forested areas. They bloom from late spring to early summer and usually grow in clumps or bunches of plants.
The plant clumps are easily separated and transplanted. Spiderwort has been used in ornamental horticulture as a showy, low-cost alternative for many years.
They expand their presence in the wild slowly, but persistently. Since there are no herbicides labeled for their control, they are considered a pest species by some hay producers.
Another plant with a colorful name, and which is considered a pest, is the rustweed (Polypremum procumbens). While it does not literally rust, it gets its name from its rust colored foliage in the autumn.
In spring and summer this low growing perennial is a Kelly green fitting for St. Patrick’s Day, and easily blends with Bermudagrass and other turfs as they make their season emergence. Tiny white blooms soon to come will confirm it presence, but this is often overlooked when in landscapes and lawns.
This plant spreads by seed, which are small and heart-shaped. One means of colonizing new areas is by seed lodging in mowing and other equipment, then depositing in new areas when the equipment is relocated.
As with all grasses in the Florida panhandle, rustweed is found only in sunny areas. This little known plant is an area native, but also occurs as far away as South America.
Rustweed, among others, in a Florida lawn. Image Credit Les Harrison
This aggressive native will quickly establish itself and push out other more desirable species. Mowing will not slow its progress.
After the multiple frost and muted earth tones, both spiderwort and rustweed are currently adding variation to the landscape’s hues as the weather warms.
To learn more about weeds in north Florida, contact your local UF/IFAS County Extension Office. Click here for contact information.
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.