by Beth Bolles | Dec 22, 2016
A new tree or shrub is an investment for the future. When we pick an ornamental plant, we have the hope that it will survive for many years and offer seasons of beauty that enhance our landscape. Time is often spent picking a suitable spot, preparing the planting hole, and watering until establishment. We give it the best of care to make certain that our new plant becomes a more or less permanent feature.
With all of our tender love and care for new ornamentals, there is one important practice that we may neglect. Most homeowners purchase plants in containers and it is common to find root balls with circling roots. If any root ball problems are not addressed before installation, the life of your plant may be shorter than you want.
Ten years after installation, this plant was ultimately killed by girdling, circling roots. Photo by Warren Tate, Escambia County Master Gardener.
The best practice for woody ornamentals is to cut any roots that are circling the trunk or container. Homeowners may slice downward through the root ball around the entire plant. For shrubs, it is recommended to shave off “the entire outside periphery of the rootball” to eliminate circling roots. These practices allow the root system to grow outward into new soil and greatly reduce the possibility of girdling roots killing your plants years after establishment.
Circling roots are cut before installation. Photo by Beth Bolles, Escambia County Extension.
For more information on shrub establishment, visit the UF Publication Planting Shrubs in the Florida Landscape.
by Beth Bolles | Nov 22, 2016
Leaf wilt may indicate more than just dry soil. Photo by Beth Bolles
Plants have specific ways of telling gardeners that there is a problem, but not all plant symptoms lead us directly to the cause. During drier conditions, we often use wilting leaves as an indicator that water is needed. This can be a reliable symptom that the soil is lacking moisture but it is not always the case. Wilting leaves and herbaceous branches actually tell us that there is not adequate water in the plant. It does not necessarily indicate lack of moisture in the soil.
There can be many reasons why water is not being absorbed by roots and moved to tissues in the plant. The obvious place to start is by checking soil moisture. If soil is powdery several inches deep around the plant, water is likely needed. However, if you ball the soil up in your hand and it holds together, there may be another reason for lack of water reaching the upper plant parts. The harder part is determining why the root system is not taking up water. Causes can be a rotted root system from too much water, a poorly developed root ball that has circling or kinked roots, and even problems in the soil such as compaction. Insects, diseases, and other pathogens can also injure root systems preventing the uptake of water.
Too much water can cause roots to decay, preventing the uptake of water. Photo by Beth Bolles
So before automatically grabbing the hose or turning on the sprinkler, do a little soil investigation to make sure that the plant wilt is really indicating lack of water in the soil. If you need help in your diagnosis, always contact your local Extension office.
by Beth Bolles | Aug 12, 2016
Homeowners and horticulture professionals spend time to develop an attractive ornamental bed only to have weeds take over months or a few years later. One common method in the attempt to prevent weeds is to apply a landscape fabric around plants in beds and place a layer of mulch on top to dress it up. The thought is that this barrier on top of the soil will prevent a large number of weeds from emerging. The fabric physically prevents the growth of weeds form the soil below and blocks sunlight from reaching weed seeds. Available fabrics are labeled as porous to allow air and water to move through them and reach ornamental plant roots.
On paper, landscape fabric sounds like a good idea and it may work for a little while. Over time, soil particles and decomposing mulch fill up the porous spaces in the fabric which prevent air and water from reaching plant roots. Even with irrigation or routine rainfall, plant roots often do not receive the needed water and air for healthy growth. Plants may respond by trying to send roots through fabric seams which breaks down the intended weed barrier. Other plants slowly decline or may die quickly due to water stress or lack of sufficient air movement into the soil.
Fabric may initially prevent some weeds but it can also prevent air and water movement. Photo by Beth Bolles, UF Extension Escambia County
Weed seeds also find their way into the mulch that is on top of the fabric from nearby lawns and landscapes. The next thing you know, you have an entire weed crop growing in the mulch on top of your landscape fabric. Perennial weeds such as torpedograss and purple nutsedge eventually grow through fabrics.
Seeds from annuals like Chamberbitter easily get into mulch from surrounding areas and grow on top of fabrics. Photo by Beth Bolles, UF Extension Escambia County
The best place to consider fabric if you want to install it in the landscape is under mulched paths or other areas without ornamental plantings where a synthetic groundcover is needed. In order to have a healthy root environment for your ornamental bed plants, it is best to keep landscape fabric out of these areas.
by Molly Jameson | Aug 12, 2016
Ants can be treated with spinosad in vegetable gardens. Photo by Molly Jameson.
There’s nothing worse than sinking your fingers into your garden soil to dig up a potato, plant a seedling, or pull up a radish, and be met with a sharp, painful sting, and little red critters rocketing up your arms. If you are a gardener in the panhandle, my bet is that you know exactly to what I refer: fire ants!
Fire ants are certainly not native to our area. These guys are an invasive species from South America that are very resilient, and many are territorial, with the potential to drive out any native ant populations. Fire ants arrived in the 1930s, and can now be found throughout most of the southeastern United States.
So when you end up with fire ant mounds engulfing your carrot patch, what can be done? Since fire ants in your garden mean fire ants in your food, the least toxic control methods are of high importance and conventional broadcast bait treatments and mound treatments should be avoided. Even in your lawn, be careful when using strong insecticidal bait treatments, as these can harm the native ant populations that help control the spread of fire ants. This can then lead to a strong resurgence of fire ant populations that can outcompete the native ants.
Although completely controlling fire ants in an area is not possible, there are sustainable management techniques that can help. Some fire ant colonies have a single queen while others have multiple queens. Either way, in order to eliminate a fire ant colony, all queens in the colony must be killed. Fire ants are omnivorous, in that they eat plants, insects, sugars, and oils. The catch is that they are only able to ingest liquids, so solid food must be brought into the colony, where larvae regurgitate digestive enzymes onto the food, breaking it down into liquids. Therefore, any method of control by ingestion will need to be in liquid form, or the ants must be able to bring the material into the colony, without first being exterminated.
Fire ants can become a problem around and in raised vegetable gardens. Photo by Molly Jameson.
There are some commercially available products that contain boric acid or diatomaceous earth. These products may reduce populations, but eliminating whole colonies with these products can be a challenge.
The use of a nervous system toxin called spinosad is effective on fire ant populations and is considered safe to use in vegetable gardens. This toxin comes from a bacterial fermentation process, and is therefore considered organic. But be aware, even though there are organic products with ingredients derived from botanical sources such as rotenone and nicotine sulfate, they should not be used in vegetable gardens. When using chemical methods of control, always follow the directions on the label carefully.
One physical method of control is the use of hot water. Three gallons of scalding water, which is between 190 to 212ºF, has been used on colonies with a success rate of 20 to 60 percent, when applied in several treatments. You will want to slowly pour the water on the colony, being extra careful not to get burned, and avoid injuring any surrounding plants. If you are like I am, and you often leave your garden hose in the hot sun, you can spray the ant colonies with the hot water, as you wait for the water to cool off enough to water the garden. Hot water control takes persistence, but you can eventually drive the ants out.
Another method of physical control is excavation. This requires digging up the mound, putting it in a bucket, and taking it to another location. Apply talcum or baby powder to your shovel handle and bucket to help prevent the ants from escaping and crawling up to sting you.
One reason fire ants are so rampant in the United States is that they have little competition or natural enemies. Scientists have released multiple species of phorid flies, natural parasites of fire ants in South America, and a few species have become established. Scientists at UF/IFAS are currently researching additional fire ant biological control methods, such as the use of a fungi, which has shown promise.
Remember, not all ants in the garden are bad guys! Many species act as roto-tillers, aerating and redistributing nutrients in the soil. They also play a role as decomposers as they assist in turning dead insects into soil nutrients. Ants can disturb garden pests by attacking them or interrupting their feeding, mating, and egg laying processes. Additionally, ants are a food source for wildlife, such as other insects, frogs, lizards, birds, spiders, and even some mammals.
by Matt Lollar | Jul 26, 2016
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.
by Daniel J. Leonard | Jul 26, 2016
The Live Oak (Quercus virginiana) is one of the most iconic figures of the Deep South. Mentioning the words Live Oak invokes all sorts of romantic nostalgia of yesteryear and the reputation is not unearned. In fact, many Live Oaks still stand that were growing on American soil when the first English settlers set foot on Plymouth Rock. They are long-lived, picturesque trees that also happen to be nearly bulletproof in the landscape. Given these factors, it is not surprising that Live Oak is far and away the most common tree included in both residential and commercial landscapes in the Coastal South. However, even the venerable Live Oak is not without its problems; this article will discuss a few of the more common issues seen with this grand species.
The Angel Oak near Charleston, SC
Few conditions afflict live oak but when they do, improper planting or cultural practices are usually at play. Observing the following best management practices will go a long way toward ensuring the long-term health of a planted Live Oak:
- Remember to always plant trees a little higher than the surrounding soil to prevent water standing around the trunk or soil piling up around it, both of these issues frequently cause rot to occur at the base of the tree.
- If planting a containerized tree, remember to score the rootball to prevent circling roots that will eventually girdle the tree. If planting a B&B (Balled and Burlap) specimen, remember to remove the strapping material from the top of the wire basket, failure to do this can also result in the tree being girdled.
Live Oak has few insect pests but there are some that prove bothersome to homeowners. The following are two of the most common pests of Live Oaks and how to manage them:
Typical galling on Live Oak
Galls are cancerous looking growths that appear on the leaves and twigs of Live Oak from time to time and are caused by gall wasps that visit the tree and lay their eggs inside the leaf or stem of the plant. The larvae hatch and emerge from the galls the following spring to continue the cycle. These galls are rarely more than aesthetically displeasing, however it is good practice to remove and destroy gall infected stems/leaves from younger trees as gall formation may cause some branch dieback or defoliation. Chemical control is rarely needed or practical (due to the very specific time the wasps are outside the tree and active) in a home landscape situation.
- Black Twig Borers can also be problematic. These little insects seldom kill a tree but their damage (reduction of growth and aesthetic harm) can be substantial. Infestations begin in the spring in Northwest Florida, with the female twig borer drilling a pen-head sized hole in a large twig or small branch and then laying her eggs in the ensuing cavity. She then transmits an ambrosia fungus that grows in the egg-cavity, providing food for the borer, other borer adults, and her offspring that take up residence and over-winter in the twig. The activity of the insects in the twig has an effect similar to girdling; the infected twig will rapidly brown and die, making removal and destruction of the infected branches a key component
In conclusion, though there are a few problems that can potentially arise with Live Oak, its premier status and continued widespread use in the landscape is warranted and encouraged. It should be remembered that, relative to most other candidates for shade trees in the landscape, Live Oak is extremely durable, long-lived, and one of most pest and disease free trees available. Happy growing!
