by Daniel J. Leonard | Oct 8, 2019
For a state that receives around 60” of rainfall a year, it is sure dry in Florida right now! In the Panhandle, the majority of our annual rainfall occurs in in bunches during winter and early spring via near-weekly cold fronts, in the mid-summer as a result of afternoon thunderstorms, and periodically in late summer/early fall if a tropical system crosses our path. Mixed in, however, are two distinct, historically dry periods: the first one in April through mid-May (contrary to popular myth, if we have May flowers, they’re gonna have to make it without April showers) and the second right now in September and October. The prolonged second dry period that we’re experiencing now makes it difficult to manage the mostly unirrigated, low-input turfgrass common in rural Panhandle lawns and pastures. It is critical to enter these expected droughts with healthy turf and remembering to employ 3 simple management tips when it quits raining (although you should follow them year-round ideally) can greatly increase your turf’s resiliency!
Unirrigated Centipdedegrass turf showing drought stress- Photo courtesy of the author.
Water Wisely – The average Florida turfgrass requires ¾-1” of water per week and we generally achieve that through rainfall. However, in our droughty months, supplemental irrigation can be a lawn saver, particularly in high traffic or more stressed areas of the yard. I realize that many of you, myself included, maintain large lawns without irrigation systems and it’s impossible to keep all your lawn well-watered during drought, but you can maintain the areas around your home, hardscapes and landscaped beds with the highest impact/visibility nicely! In these areas, put down no more than ¾” of water per irrigation event, a ballpark number that ordinarily allows the turf root zone to become saturated. Measuring your sprinkler’s water output is easily done by setting several straight-sided cans (tuna or cat food containers work great) under the sprinkler and timing how long it takes to achieve 3/4”. You might be surprised how much water you waste by leaving a sprinkler running for an hour or more!
Apply Herbicides Appropriately – Herbicides are a great item to have in the turf care toolbox, but if used incorrectly can be a waste of time and money at best, harmful to your turf at worst! Once turf and associated weeds become drought stressed (turning bluish gray, obvious wilting, leaves curling, etc.), it is too late for weed control with herbicides. There are a couple of reasons for this. First, when plants get stressed, they slow or stop their growth and focus on survival. This survival response prevents herbicides from being taken up properly and ultimately causes ineffectual weed control. Also, many herbicides specifically state on the product label that they should not be applied during certain conditions (drought, temperatures above 85-90 degrees, etc.). It is critical that one adhere to these label directions as applying the incorrect product in hot and dry conditions can cause volatility, drift to non-target plants, and in some cases, toxicity to turf you’re treating in. When it’s droughty like it is now, leave the herbicides in the chemical shed to prevent wasting your time and money and potentially damaging non-target plants!
Unirrigated Centipedegrass turf showing drought stress – photo courtesy of the author
Raise that Deck – Finally, one of the most important turf management strategies during an extended drought is to reduce mowing and raise your mower’s cutting height when/if you do mow. As mentioned above, plants are already stressed during a drought and physically chopping off a chunk of the turf plant stresses it further, causing an energy-intensive wound response when the plant is actively conserving resources for survival. Therefore, if you just HAVE to mow, raise the cutting height as high as possible to make the smallest injury possible on the grass and keep your mower blades sharp to ensure a clean cut, which will heal easier and require a smaller energy response from the plant.
During droughts like the one we’re currently in, there isn’t one silver bullet to keep your non-irrigated turf looking good. However, there are several strategies you can use throughout the year to get your lawn through dry times. Remember to water ¾”-1” per week when you can, where you can. Before you water, calibrate your sprinkler to ensure you put out enough water and don’t waste your time and inflate your utility bill by putting out too much! Reduce or eliminate use of herbicides as they are ineffective during stress periods and can harm your turfgrass. Finally, reduce or eliminate mowing and if you must mow, raise the deck! If you have any questions about getting your turf through the drought or other horticultural or agronomic topics, please contact your local UF/IFAS Extension Office!
by Les Harrison | Oct 8, 2019
Mushrooms growing on the roots of trees is a bad sign. This indicates the roots are decaying and the tree will soon become (or already is) unsafe.
On the doorstep of autumn, the weather is making its seasonal change in north Florida. It has been a bit cooler in the mornings, but the afternoons still qualify as hot.
What the winds of October will blow in is still anyone’s guess, but last year it was Hurricane Michael. Unfortunately, the storm’s brunt came in causing severe damage to homes, businesses and marine enterprises in several counties.
October is typically the month when tropical cyclone activity lessens in the Atlantic, but accelerates in the Gulf of Mexico. While beastly events like Hurricane Michael are relatively rare, it only takes one such incident to necessitate recovery efforts and expenses for years, if not decades.
The prudent course of action is to prepare for the worst while hoping for the best. One area of preparation where residents can have a distinctly positive effect is readying their trees for the potential assault.
Damage from falling trees and limbs is a major cause of destruction during tropical storms and hurricanes. Removing potential problems before the storm can minimize harm to structures and injury to residents.
Trees in decline are especially hazardous. Their compromised health makes them subject to uprooting and breakage with far less force than would effect a healthy tree.
There are several key indicators for tree health. Any single factor or a combination can mark a tree as unsafe.
Mushrooms growing on or very close to trees is a sign the tree is dying. The fungus is not the cause of decline, but only an indicator of the eventual fate.
Spores of the mushrooms are scattered by wind and water. Landing randomly, most arrive on a site devoid of necessary resources and never sprout.
Those lucky spores which land on decaying wood will likely sprout and take nourishment from the rotting plant material. Their roots accelerate the decomposition of the wood by consuming the available material and exposing more of the tree to colonization by mushrooms.
Sites on trees and plants infected with mushrooms typically are break points when pressure or stress is applied. If the mushrooms are located at the base of the tree, it is likely to be detached from its roots and topple over in heavy winds.
Another indicator of tree health is its crown, or the uppermost branches and leaves. Healthy trees and plants have full, green, and growing crowns.
When the crown turns brown and the leaves drop off, it is a good indicator the tree’s days are numbered. The causes may be disease, lightning, or mechanical interruption of the root system.
Lastly, bifurcation or trunk forking is a sign of a structurally weak tree. This condition may display itself when the tree emerges from the ground or at an elevated place on the mature tree trunk.
When the wind direction stresses the tree with enough force at its angle of vulnerability, a collapse results. Unfortunately, there is no simple way to tell how much wind is required to produce the failure.
Any tree with these problems should be evaluated by a certified arborist and removed when necessary. It may result in an expense now, but can save on expenses, inconvenience and aggravation if a storm randomly removes the tree in the future.
The question must be asked: Is it worth the gamble to wait on the winds of October?
To learn more about the tree health in north Florida, read the UF/IFAS publication HOW TREES GROW IN AN URBAN ENVIRONMENT.
by Sheila Dunning | Sep 7, 2019
“There are these weeds spreading all over my yard. They have little round leaves that are real close to the ground and creep in every direction. I keep trying to get rid of them by mowing my grass shorter, but they are killing my grass. What are they and how do I get rid of them?” Here at the Extension office, this is a conversation I have had nearly daily for the past month. We are here to help with identification and control of many landscape problems, including weeds.
However, my first word of advice is to change the mowing practice. Short, spreading weeds cannot be mowed out. You need to do just the opposite. Mowing as high as possible (3-4”) will help to reduce weeds by shading them out, therefore, reducing their spread.
In every instance, the weeds have been common lespedeza (Kummerowia striata (Thunb.) Schind syn. Lespedeza striata) and/or prostrate spurge (Euphorbia maculata syn. Chamaesyce maculata). Both grow close to the ground with a spreading habit. Both have small, rounded leaves and produce small, light-colored flowers. But, if you look close, there are significant differences that will help with identification.
Common lespedeza, also known as Japanese clover, is prostrate summer annual that forms 15-18 inch patches. The stems are wiry. It has dark green trifoliate 
(arranged in threes) leaves with three oblong, smooth leaflets. Leaflets have parallel veins nearly at right angles to a prominent mid-vein. Its leaves have smooth edges and a short spur at the tip of each leaflet. Flowers appear in late summer with small pink to purple, single flowers found in leaf axils on most of the nodes of the main stems. As common lespedeza matures, the stems harden and become woody.
Prostrate spurge is a summer annual broadleaf weed that spreads by seed. The leaves are oval in shape, small, and opposite along the stem. As it matures, a red spot may form in the center of the leaf, earning it the common name spotted spurge. Another distinct characteristic is the stem contains a milky sap that oozes when the stem is broken. Light pink to white-colored flowers appear from early-summer through the fall.
Both are annual,broadleaf weeds, so there are several post-emergent herbicides available to kill the ones present. Don’t forget the pre-emergent herbicide application in late winter though. These weeds can drop plenty of seed. The importance of knowing which weed you have is more about the message they are trying to send you. These weeds can indicate other issues that may be part of the reason the grass is thinning and allowing the weeds to take over in the first place.
Common lespedeza is a legume. It thrives when water is plentiful and soil nutrients are low. If this is the weed “taking over” your yard, you need to get a soil test and evaluate your watering habits. Improving fertility and reducing soil moisture will naturally weaken common lespedeza.
If your thin patches of declining grass are being replaced with spurge, it may be time to submit a sample for a nematode assay. Research has shown that spurge is a weed that can thrive with high populations of nematodes. Turfgrass species are easily harmed by nematodes (microscopic roundworms that imbed into and on grass roots). If the assay indicates harmful population levels, unfortunately there are few options for reduction of the nematodes. However, several ornamental plants are tolerant. So, you may need to consider creating a landscape bed area rather than continuing to battle poor-looking grass.
Weeds can serve as indicators to soil conditions that may need to be addressed. Learning to identify weeds may teach you more than just their names.
by Daniel J. Leonard | Aug 12, 2019
As an unabashed plant enthusiast who’s been experimenting with new plant introductions (some not really “new”, just new to me) in his own landscape, and his parent’s yard before that (sorry guys for the ‘Charmed Wine’ Oxalis that now pops up unwanted every spring) for nearly two decades now, at this point I’m pretty hard to impress. However, last year Andrea Schnapp, a UF/IFAS Walton County Master Gardener, introduced me to a newish plant that has since changed the way I choose plants to color shady pots and planting beds, a little native of tropical South America called Bush Violet (Browallia spp.), specifically the hybrid ‘Endless Illumination’.
Browallia ‘Endless Illumination’ on the author’s back porch.
For decades, the standard bedding plant for color in the shade in the Deep South has been Impatiens walleriana. However, in the last few years, a new disease called Impatiens Downy Mildew has wreaked habit on the bedding plant species, virtually eliminating it as a serious player in the horticulture industry. Fortunately, the fine folks at Proven Winners introduced ‘Endless Illumination’ a couple of years ago to fill the niche formerly occupied by old-fashioned Impatiens. And boy, is ‘Endless Illumination’ aptly named. The unending masses of star shaped flowers are an absolutely brilliant purple hue that does indeed light up shady areas in the landscape. I’ve encountered few plants put forth such a proliferous display of flowers for as long of a time as this Browallia selection has, and it doesn’t even require deadheading!
Browallia ‘Endless Illumination’ flowers.
In addition to having one of the more striking color displays of any bedding plant, Browallia happens to be a vigorous grower with an extremely hardy constitution. I’ve found ‘Endless Illumination’s mature size as listed on the sales tag as being a little conservative, instead of the 16” tall x 14” wide stated, my samples have consistently grown more than the 16” listed in height and doubled the width, no complaints here as this just means more flowers! And though my experience with Browallia has strictly been in containers so far, it has weathered heat and bounced back from drought like a champ. It’s not super important to know that the container it occupies is sited under my back porch roof and therefore is subjected to human induced drought by my forgetting to water it, good performance in droughty conditions is good performance in droughty conditions! Finally, Browallia requires the bare minimum of fertilizer to thrive. A good topdressing of a slow-release fertilizer (rates according to the product’s label, of course) at planting and an identical refresher dose mid-summer have induced great performance and no noticeable nutrient deficiencies.
Browallia ‘Endless Illumination’ flowers
A quick note before we adjourn, when perusing nurseries next spring for Browallia, you’ll likely encounter the sister cultivar of ‘Endless Illumination’ with white flowers, named ‘Endless Flirtation’. I’d encourage you to stick with the purple flowers of ‘Endless Illumination’ as I’ve found, through personal growing experience and anecdotes from other growers, ‘Endless Flirtation’ to be noticeably fussier than and not nearly as attractive as its sister plant.
Sometimes, the misfortunes of one plant are a merely an opportunity for another plant to claim its place in the flower bed. Browallia ‘Endless Illumination’ has taken the spot occupied by Impatiens walleriana and quickly become a garden favorite. Look for this awesome little annual in garden centers next spring! And remember, if you have any questions about this newly introduced plant or any other horticultural topic, please contact your local UF/IFAS Extension office! Happy gardening!
by Sheila Dunning | Aug 7, 2019
Damage caused by azalea lace bug, Stephanitis pyrioides (Scott), feeding. Photograph by James. L. Castner, University of Florida. Severely damaged leaves become heavily discolored and eventually dry or fall off. Symptoms may sometimes be confused with mite injury, but the presence of black varnish-like excrement, frequently with cast skins attached, suggest lace bug damage (Johnson and Lyon 1991).
You may be noticing the color disappearing from your azaleas right now. Do your azaleas look bleached out from a piercing-sucking insect. The culprit is probably azalea lace bug, Stephanitis pyrioides. This pest overwinters in eggs on the underside of infested leaves. Eggs hatch in late March and early April. The insect then passes through five nymphal instars before becoming an adult. It takes approximately one month for the insect to complete development from egg to adult and there are at least four generations per year. Valuable plants that are susceptible to lace bug damage should be inspected in the early spring for the presence of overwintering lace bug adults, eggs and newly-hatched nymphs. Inspect these plants every two weeks during the growing season for developing lace bug infestations.
Both adults and nymphs have piercing-sucking mouthparts and remove sap as they feed from the underside of the leaf. Lace bug damage to foliage detracts greatly from the plant’s beauty, reduces the plant’s ability to produce food, decreases plant vigor and causes the plant to be more susceptible to damage by other insects, diseases or unfavorable weather conditions. The azalea can become almost silver or bleached in appearance from the feeding lace bug damage.
However, lace bugs often go undetected until the infested plants show severe damage sometime into the summer. By then several generations of lace bugs have been weakening the plant. Inspecting early in the spring and simply washing them off the underside of the leaves can help to avoid damage later and the need for pesticides.
Adult lace bugs are flattened and rectangular in shape measuring 1/8 to 1/4 inch long. The area behind the head and the wing covers form a broadened, lace-like body covering. The wings are light amber to transparent in color. Lace bugs leave behind spiny black spots of frass (excrement).
Adult azalea lace bug, Stephanitis pyrioides (Scott), and excrement. Photograph by James. L. Castner, University of Florida.
Lace bug nymphs are flat and oval in shape with spines projecting from their bodies in all directions. A lace bug nymph goes through five growth stages (instars) before becoming an adult. At each stage the nymph sheds its skin (molts) and these old skins often remain attached to the lower surface of infested leaves.
Nymphs of the azalea lace bug, Stephanitis pyrioides (Scott), with several cast skins and excrement. Photograph by James. L. Castner, University of Florida.
Azalea lace bug eggs are football-shaped and are transparent to cream colored. Lace bug eggs are found on the lower leaf surface, usually alongside or inserted into a leaf vein. Adult females secrete a varnish-like substance over the eggs that hardens into a scab-like protective covering.
Other plant species, such as lantana and sycamore, may have similar symptoms. But, realize that lace bugs are host specific. They feed on their favorite plant and won’t go to another plant species. However, the life cycle is similar. Be sure to clean up all the damaged leaves. That’s where the eggs will remain for the winter. Start next spring egg-free.
For more information go to: http://entomology.ifas.ufl.edu/creatures/orn/shrubs/azalea_lace_bug.htm
