Summer Annual Weeds Thriving in Panhandle Lawns

Summer Annual Weeds Thriving in Panhandle Lawns

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.

Summer Rains Can Create Obstacles for Panhandle Blueberries

Rabbiteye Blueberry cultivars are the primary species grown in the Panhandle and are much more popular than the Southern Highbush Blueberry that dominates production further south. Our environment is more hospitable to Rabbiteye; consequently, they tend to be more drought tolerant and less susceptible to disease. The harvest season for Rabbiteye Blueberries is also relatively long.  Harvesting can extend from May to July, depending on cultivar selection.

Rabbiteye blueberry season starts to wrap up this month in the Panhandle, as late season cultivars begin their mature fruiting stage. This is also the time of year when we receive seemingly daily afternoon thunderstorms. These frequent rainfall events can compromise blueberry plants over the long term if good management measures are not in place.

Blueberry

Blueberry. Photo credit: Eric Zamora, UF IFAS.

One of the primary issues experienced with Rabbiteye Blueberry is Phytophthora Root Rot (PRR).  This disease is a problem this time of year due to increased rain events and poor draining soils. PRR is caused by the fungus, Phytophthora cinnamomic. Infection by this fungus can lead to plant death if not managed; however, it is a condition that is easier to detect than most diseases. A clear sign of infection is the appearance of symptoms resembling fall color development in the foliage (leaves turning various shades of yellow, orange and red).  Foliage color change is followed by leaf drop. A preventative fungicide can be used to treat this condition, but cultural methods (such as transplanting in well drained soils and using at least 3” of pine bark as mulch) will greatly reduce the risk of infection. Remember, blueberries, like azaleas and camellias are also acidic soil loving plants. Soils in the pH range of 4.0-5.5 are necessary for overall plant health and high fruit yields. Pine bark mulch, in addition to improving drainage and organic matter content, will assist in maintaining an acidic pH.

Botrytis Flower Blight or Gray Mold, caused by Botryospheria spp., is another potential issue experienced in late spring/early summer due to lingering moisture. To prevent Botrytis, avoid any overhead watering during the budding and flowering stage or keep watering to the early morning hours so moisture doesn’t linger overnight. Stem Blight can also occur this time of year. Symptoms of Stem Blight are of dying branches, which should simply be removed with sharp shears. There is no chemical control for stem blight and the best defense against this condition is good cultural practices that will in turn reduce plant stress.

In addition to potential fungal diseases, increased summer temperatures and rainfall often also bring an increase in insect populations. Most insecticides that are safe for ornamental landscape plants and fruit crops are safe for blueberries, just be sure to check the label for application rates, directions and precautions. Also, pay close attention to the label for the HI or harvest interval. This is the number of hours or days that need to pass before you can safely harvest fruit once an application of insecticide is made.

For more information on growing blueberries, please contact your local county extension office.

Supporting information for this article can be found in the UF/IFAS EDIS publication, “2017 Florida Blueberry Integrated Pest Management”, by Jeffrey G. Williamson, Phillip F. Harmon, Oscar E. Liburd & Peter Dittmar: http://edis.ifas.ufl.edu/pdffiles/HS/HS38000.pdf

& “Blueberry Gardener’s Guide”, by J. G. Williamson, P. M. Lyrene, and J. W. Olmstead: http://edis.ifas.ufl.edu/pdffiles/MG/MG35900.pdf

 

UF/IFAS Extension is an Equal Opportunity Institution.

 

Late Spring Signals Leaf Gall for Some Camellias

Camellias are a Panhandle favorite, as the flowers can highlight a landscape with bright, vibrant colors in fall and winter. However, spring time can bring about these colors in a negative way, in the form of leaf gall.

The camellia is native to Asia and brought to America in the late 1700’s. These plants have proven to be a dependable addition to the southern landscape with minimal care. When camellias are correctly planted and cared for, minimal disease problems arise. However, camellias can contract leaf spot, dieback, root rot and bud and leaf gall.

Camellia Gall Credit: Patty Dunlap, Gulf County Master Gardener.

 

Leaf and bud galls are caused by the fungus Exobasidium vaccinia. The gall appears as thickened, waxy and enlarged leaves or buds during the cool spring months. One or several leaves on a single shoot may be affected. Once you’ve found infected leaves, no chemical control will be effective. Actually, no fungicide has been found very effective in combatting this condition. However, control can be accomplished in the home garden by simply pinching off and destroying infected leaves. Disease activity usually stops with warmer weather. A best management practice to curb infection is to reduce overhead watering during cool, wet weather periods of spring. Great news, this condition does not cause any long-term issues with the plant.

For more information regarding fungal issues in landscape plants, contact your local county extension office.

Fun camellia fact: The young leaves of the species, Camellia sinensis, are processed for tea, one of the world’s most popular drinks. Please see UF/IFAS EDIS publication, “Tea Growing in the Florida Landscape” by Jonathan H. Crane and Carlos F. Balerdi: http://edis.ifas.ufl.edu/pdffiles/HS/HS30800.pdf

Supporting information for this article can be found in the UF/IFAS EDIS publication, “Camellias at a Glance” by Sydney Park Brown: http://edis.ifas.ufl.edu/pdffiles/EP/EP00200.pdf

UF/IFAS Extension is an Equal Opportunity Institution.

The Mystery of Florida Betony

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

 

 

 

 

 

 

 

An Uphill Battle for the Leyland Cypress

An Uphill Battle for the Leyland Cypress

Figure: Passalora Needle Blight in Leyland Cypress. Image Credit Ray Bodrey

Leyland cypress (Cupressocyparis leylandii) has been a very popular landscape tree in the U.S. for many decades. It has endearing characteristics, most notably its fast-growing nature and ability to make an appealing boundary around property. However, various diseases have created an overwhelming survival hurdle.

Seiridium or Botryosphaeria cankers (also referred to as dieback) are fungal diseases that can strike Leyland cypress. In general terms, cankers are multiple dark oval lesions that are usually sunken into the bark. The lesions are accompanied by the flow of resin. Discolored branches will be seen first as an indicator. If the fungus finds its way into the body of the trunk, most likely the tree will not survive. With Seiridium canker, girdling of branches and stems is not an issue, however needles will fall off the branches easily. With Botryoshaeria canker, stem girdling will occur, killing the branch, but needles generally will stay on the branch.

Passalora Needle Blight or commonly known as twig blight, caused by the fungus Passalora sequoia, is a major concern in the Southeast. The disease is usually more active in the spring and summer months and affects mostly younger growth. Symptoms of the disease are the browning of needles, followed by needle drop. Disease usually begins on the lower part of the tree and moves up. Sometimes the disease is widespread on one side of the tree only, where sunlight is not able to dry moisture quickly. Ventilation is key when planting these trees as a border hedge. However, the Panhandle environment and climate is very conducive for these pathogens to affect the vulnerable Leyland cypress.

If you have or will plant Leyland cypress, there are some fungicide options to consider as preventive maintenance. It’s important to stress that trees that are already infested, will succumb to the disease regardless of treatment. Fungicides such as Daconil & Mancozeb (Pentathlon) can be used in the spring & fall. Propiconazole is the best fungicide for the warmer, summer months (June through August). Fungicides such as Myclobutanil or Thiophanate-methyl are also commonly used. Always read application directions and pay close attention to the application rate interval.

There are other evergreen options, that have a much higher likelihood of not contracting a fungal disease that can cause terminal results. Native species like the red cedar (Juniperus virginiana) or white cedar (Thuja occidentalis) are great choices. Again, these species are not totally immune to twig blight or other fungal pathogens, but they are hardier and less likely to contract diseases. For more information, please contact your local county extension office.

Supporting information for this article can be found in the following the UF/IFAS EDIS publication, “Cupressocyparis leylandii: Leyland Cypress” by Edward F. Gilman and Dennis G. Watson: http://edis.ifas.ufl.edu/pdffiles/ST/ST67100.pdf & the Clemson Cooperative Extension Publication, “Leyland Cypress Diseases & Insect Pests”: http://www.clemson.edu/extension/hgic/pests/plant_pests/trees/hgic2004.html

UF/IFAS Extension is an Equal Opportunity Institution.