Gardeners are always fighting the endless weeds that pop up in landscape and flower beds. When homeowners put in a new landscape bed and want to prevent future weed invasions, many think that putting down landscape fabric is a great way to keep the weeds from emerging and protect the newly planted trees, shrubs or perennials.
An example of failure of landscape fabric to control weeds less than 2 years after planting. Note the peeking through at the edges. Photo credit: Mary Salinas, UF/IFAS Extension.
Is Landscape fabric a good choice? Why or why not?
If landscape fabric is not covered up, sunlight will degrade the fabric. When mulch is placed on top of the fabric (and we all do want to cover it up – the fabric is not very attractive) the mulch breaks down into soil. Inevitably, weed seeds blow in and settle and germinate and grow on top of landscape fabric. And here you are with a weed problem. Weeds also find their way into the openings cut for desirable plants and along the edge of the fabric.
Landscape fabric is porous when put in place to allow water to pass through, but as time passes, the pores can get clogged and water penetration is restricted – rain and irrigation runs off and the plants you meant to protect are not getting the water they need.
Maybe the worst effect is that the landscape fabric creates unfavorable soil conditions. A healthy soil is key to good plant health. One thing soil needs to have is an exchange of carbon dioxide and oxygen between the soil and the atmosphere. Recent studies from Washington State University demonstrated that gas movement between the soil and the atmosphere is restricted about 1,000 times more when landscape fabric is present than when areas have only wood mulch.
So, if landscape fabric is not a good choice, what is?
Mulch made from wood, bark, fallen leaves and pine needles. See Gardening Solutions: Mulch for sustainable ideas.
Weeds identification and management is still one of the most common questions we receive at the local UF IFAS Extension office. Learn about the chamberbitter weed that can grow in turf and ornamental beds and the multi faceted approach that is necessary for management In the Garden with Beth Bolles, UF IFAS Extension Escambia County.
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
Nothing looks better than a fence clean from weeds right? It all depends on the goal you have in mind. If you want to one day receive the infamous honor of “yard of the month”, than you might want the cleanest and straightest fence around. If you have goals of providing a habitat for wildlife and beneficial insects, some selective strategies need to be implemented. Providing a habitat for beneficials can easily be achieved through minimal maintenance and selective plant removal.
A typical clean fence row. Photo Credit: Iowa State University Extension
If you are starting with a clean fence free of herbaceous plants, shrubs, vines, and trees then you have two options: Replant vegetation for the ideal habitat(1) or allow for natural plant succession to take its course(2). If you chose option 2, that’s it, you’re done. However, if you chose option 1 then you begin the search of garden centers for desirable plants.
In order to pick the best plants, you will need to think about what you want to attract. Do you want to attract vertebrates, invertebrates, or a little of both? Vertebrates are attracted to plants that provide shelter and food. A good start for selecting plants would be to read the publication “Native Plants That Benefit Native Wildlife in the Florida Panhandle”.
As you already know, pollinator insects are attracted to nectar and pollen. However, beneficial insects cannot survive on just eating bad bugs and they need supplemental nutrition. They receive this supplemental nutrition by way of extrafloral nectaries. Extrafloral nectaries are nectar-producing glands located on plant parts other than the flowers. They can be located on plant leaves, stems, or fruit. A list of plants containing extrafloral nectaries can be found in the publication “Many Plants Have Extrafloral Nectaries Helpful to Beneficials”.
A milkweed assassin bug. Photo Credit: Texas A&M University.
Although it’s great idea to attract wildlife to your fencerows, it is important to choose plant material based on your fence’s location in vicinity to your house. Fire can easily jump from plant material to fences to your house. The Firewise Communities Guidelines should be followed for landscaping your home.
Burweed, Soliva Sessilis. – Image Credit: Joseph M. DiTomaso, University of California – Davis, Bugwood.org. Creative Commons License
This spring, lawn burweed has been an especially noticeable problem in lawns. Extension offices throughout Northwest Florida have been fielding many questions and finding solutions to lawn burweed infestations!
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.
Aside from herbicides, 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 cultural methods aren’t sufficient, science has given us several options to control this irksome pest. Herbicides containing the active ingredients dicamba, 2,4-D or atrazine are good at controlling burweed as a post emergence control when applied from December through March. Be careful to use reduced rates on centipede and St. Augustine lawns, and never use more than the labeled rate since injury can occur when using these products on these species. Later applications have less effect on burweed because as it matures it is harder to control. Additionally the burs, once present on the lawn, are hard to remove. As the daytime temperatures rise to 90ºF, some of these herbicides may cause lawn damage. Try to keep the spray residue outside of the root zone of desirable plants to avoid injury and always follow label directions.
Be aware that burweed reproduces by seed, so mowing it down will only increase the problem by burying the seed for fall germination. Although we are now in the month of May, control of actively growing burweed might still be warranted if it is still flowering and setting seed. As temperatures warm up burweed will die, as it is a winter annual. In cases where it is already dying, control is not warranted since the natural cycle of winter annuals is concluding.
If an infestation of burweed has occurred this year, take note. The best time to apply pre-emergent herbicides to control burweed is in October. A widely used preemergence 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.
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 during the upcoming fall so that lawns will be burweed free next spring.
