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 Mark Tancig | Oct 9, 2017
The network of backcountry roads winding through north Florida offer pleasant views of rolling pastures, fields of cotton, old tobacco barns, and, occasionally, a scenic overlook of our local “hills”. Many of these roads follow the original trails blazed by early settlers, or even Native Americans. Traveling along these small roads during the late summer and fall, drivers are also presented with an abundance of wildflowers along the road. It’s fun to imagine travelers of past generations being awarded the same colorful displays in days of yore.
Traveling a country road in 1905 when they were all country roads! Likely enjoying same roadside wildflowers. Credit: State Archives of Florida – Hays.
Some of the most common roadside wildflowers of late summer include Spanish needles (Bidens alba), goldenrod (Solidago spp.), silkgrass (Pityopsis spp.), slender scratchdaisy (Croptilon divaricatum), goldenaster (Chrysopsis spp.), and, one that the early settlers wouldn’t have seen, showy rattlebox (Crotalaria spectabilis), an invasive, exotic species that was introduced in the 1920’s.
Spanish needles. Credit: Brent Sellers – UF/IFAS.
Goldenrod. Credit: Larry Williams – UF/IFAS.
Silkgrass. Credit: JC Raulston Arboretum – NC State University.
Scratch daisy. Credit: Center for Aquatic and Invasive Plants – UF/IFAS.
Showy rattlebox. Credit: Doug Mayo – UF/IFAS.
Many of these roadside wildflowers can also be found in home lawns and landscapes, usually in areas infrequently mowed, such as fence lines and field edges. Except for showy rattlebox, these roadside wildflowers are native species adapted to dry, disturbed sites, like roadsides. These native species provide ecosystem services to many native insects and other pollinators, including honey bees. Depending upon site particularities, allowing these plants to thrive in the residential landscape can provide similar ecosystem services and similar reward of color as is found along country back-roads.
While most folks would probably just consider these plants weeds, that determination depends upon an individual’s situation and each gardener’s opinion. In one yard, maybe it’s a weed, but along the roadside, it’s called a wildflower! Certainly, if left to set seed, these plants will spread. Mowing prior to seed maturity can help keep them in check while still getting a temporary show of color. Again, any showy rattlebox should be controlled since it is an invasive, exotic species that can invade natural Florida ecosystems and smother native plants. It’s also toxic to many animals if ingested.
North Florida’s roadside wildflowers are a pleasure see while cruising the back roads. If recognized and allowed to grow in residential landscapes, these plants can provide the same aesthetic and environmental benefits.
If you are interested in what’s growing in your yard, or local roadside, contact your county’s UF/IFAS Extension office.
by Sheila Dunning | Oct 2, 2017
Silkgrass Pityopsis spp. Picture by: Sheila Dunning
Each fall, nature puts on a brilliant show of color throughout the United States. As the temperatures drop, autumn encourages the “leaf peepers” to hit the road in search of the red-, yellow- and orange-colored leaves of the northern deciduous trees.
Here in the Florida Panhandle, fall color means wildflowers. As one drives the roads it’s nearly impossible to not see the bright yellows in the ditches and along the wood’s edge. Golden Asters (Chrysopsis spp.), Tickseeds (Coreopsis spp.), Silkgrasses (Pityopsis spp.), Sunflowers (Helianthus spp.) and Goldenrods (Solidago spp.) are displaying their petals of gold at every turn. These wildflowers are all members of the Aster family, one of the largest plant families in the world. For most, envisioning an Aster means a flower that looks like a daisy. While many are daisy-like in structure, others lack the petals and appear more like cascading sprays.
So if you are one of the many “hitting the road in search of fall color”, head to open areas. For wildflowers, that means rural locations with limited homes and businesses. Forested areas and non-grazed pastures typically have showy displays, especially when a spring burn was performed earlier in the year.
With the drought we experienced, moist, low-lying areas will naturally be the best areas to view the many golden wildflowers. Visit the Florida Wildflower Foundation website, www.flawildflowers.org/bloom.php, to see both what’s in bloom and the locations of the state’s prime viewing areas.
And if you are want to add native wildflowers and other Florida-friendly plants to your landscape join the Master Gardeners for their Fall Plant Sale to be held Saturday, October 14 from 8 am to noon at the Okaloosa County Extension Annex located at 127 SW Hollywood Blvd, Ft. Walton Beach.
by Les Harrison | Oct 2, 2017
While yard work is important to maintain an attractive lawn, if done successfully, the resident can spend quality time in other pursuits like watching the wildlife from the front porch.
With the passing of September the end is in sight, well at least the end of summer, and hopefully summer-like weather. The hot humid days of August gave way to the hot humid days of September,now October, and the Florida Panhandle is finally experiencing cooler temperatures. At least temporarily.
Days have shortened noticeably and the plants have noticed. Foliage growth has slowed and seed production is in overdrive.
As the season slowly shifts, the needs and care for the lawn and landscape are changing too. Inputs need six months ago and environmental factors which were true in the spring are now being altered by the immutable and timeless forces of nature.
Fertilizer is one factor which must be considered in light of the dormant season’s approach. Inappropriate or excessive application will waste resources and end up in the water supply where it will do no good.
As many warm season grasses and plants are reducing their growth rates to prepare for winter, the need for nutrients slows. Nitrogen, the first number on a fertilizer tag’s list of ingredients percentages, is especially vulnerable to misuse by the well-intended but inexperienced or uninformed person.
Over application of nitrogen will promote the aggressive growth of tender green foliage in the lawn. If a frost or freeze occurs when the tender vegetation is presence, the plant will experience excessive damage or death.
The directions on home and garden fertilizer bags, and soil test report all recommend restricting or eliminating nitrogen application late in the growing season. This is sound advice.
Herbicide use changes in the late summer and autumn also. As with misapplied fertilizer, misused herbicides will waste resources and can end up in the water supply.
Weeds and other targets of herbicides must be actively growing for the herbicide to work effectively. Late summer and fall can present challenges to effectively applying herbicides.
With very few exceptions, plants must be actively growing for herbicides to work properly. Plants slowing towards dormancy will not absorb as much herbicide and may, species depending, be completely immune.
Herbicides do not work on plants which are under drought stress. It is important to remember early fall is the driest time of the year in panhandle Florida, nature’s way of forcing a fall growth shutdown.
Yard waste and grass clipping will help refresh mulch in flower beds and on tree root zones. The summer heat and humidity have combined with bacterial activity to breakdown the current supply of mulch.
The on-site utilization of yard waste as mulch or as a basis for compost is a good practice to establish. It will benefit the landscape and reduce the multiple layers of expenses required to collect, haul and dispose of this material.
If properly composted, the material reduces the chances of introducing weeds, insects and diseases which can be on commercial products. Another way to look at the subject is “What is produced in the Florida Panhandle stays in the Florida Panhandle…and saves everyone money in the process.
While Septembers early weeks were just as oppressively hot and humid as August, relief seems to be here. Be ready to spend the cooler days enjoying a private bit of paradise in Northwest Florida without worrying about problems which could have been avoided.
To learn more about getting the lawn and landscape ready for autumn, contact your UF/IFAS Extension Office.
by Matt Lollar | Oct 2, 2017
Over the last month or so, home gardeners and commercial growers alike have noticed what look to be large dust particles floating through the air. It’s probably not uncommon to have inhaled a few or even a few hundred of these mysterious particles. Most likely, these “particles” aren’t dust at all but whiteflies instead. Whiteflies are small (less than a tenth of an inch long), white, soft-bodied insects. They aren’t flies but are considered ‘true bugs’ by entomologists. The most common whitefly species in Northwest Florida is the silverleaf whitefly, also known as the sweetpotato whitefly. Whitefly numbers have exploded exponentially this year because of last years’ mild winter. These irksome insects feed on a variety of annuals, shrubs, vegetables and trees.
Magnified whitefly adults and eggs. Photo Credit: James Castner, University of Florida/IFAS.
Whiteflies typically feed on the underside of leaves. Initially, disturbed leaves will become pale in color, then a sticky substance may develop on the surface of the leaves. This sticky substance is called honeydew. Honeydew is actually a sugary substance excreted by the whiteflies as part of their elimination process, similar to what aphids and scale insects produce. After honeydew is deposited, sooty mold develops to feed on this readily available sugar source. Sooty mold is a fungus that forms a gray to black colored coating on plant leaves. It normally grows on leaves that were previously covered with honeydew. Sooty mold hinders the ability of leaves to absorb light and ultimately limits photosynthesis.
Pale squash leaves due to feeding from whiteflies. Photo Credit: University of Florida/IFAS.
So what should be done to control whiteflies? It depends on what is being grown. If whiteflies are present, the role of beneficial insects should be taken into consideration. Plenty of predatory insects such as lady bugs and green lacewings are around to feed on whiteflies. In fact, leaving the whiteflies alone on your trees and shrubs will attract more predatory insects. Below are some whitefly control methods that produce minimal damage to beneficial insect populations.
Whitefly Control in Vegetables
- Sticky Traps – Yellow sticky traps are a good way to monitor whitefly populations and can help determine when insecticide application is appropriate.
- Insecticidal Soaps – Insecticidal soaps are usually applied as a 1 to 2 percent solution (2½ to 5 tablespoons per gallon of water). It is important to follow the application directions on the label. Insecticidal soap should be applied in the evening, when the sun is low in the sky and the temperature is below 85°F. Some insecticidal soaps available at local lawn and garden centers include: Bonide Insecticidal Soap, Bonide Insecticidal Soap, and Bayer Advanced Natria Insecticidal Soap.
- Horticultural Oils – Horticultural oils should be handled like insecticidal soaps. Like the soaps, they should be applied in the evening. Some horticultural oils available at local lawn and garden centers include: Bonide All Seasons Spray Oil, Southern Ag Parafine Oil, and Garden Safe Neem Oil.
- Other Insecticides – Harsher chemicals are not recommended for the home gardener, because whiteflies have become resistant to most products on the market. Use of broad spectrum insecticides may also contribute to an increase in whitefly populations because they kill beneficial predatory insects.
Hopefully winter will be cooler this year and the profuse whitefly population will be knocked back. Until then, we wish all home gardeners the best of luck with fall gardening!
