The Pensacola area has had its fair share of rough weather lately. While the recent storms were not hurricanes, the rainfall totals rivaled many tropical storms, and the lighting and wind were disastrous. A tornado caused significant damage, including a tragic death, with more tumultuous weather in the forecast. Our rainy hurricane season has just begun, so it is worth talking about tree selection, management, and preparing for storms.
After the busy 1992, 1995, 1998, and 2004-05 hurricane seasons, several University of Florida researchers undertook an exhaustive on-the-ground project to look at tree damage statewide. Their goal was to determine which species survived high winds, and which trees were the most vulnerable during storms. Their findings were consistent, and have held up over the past few decades. A full description of the project can be found online, along with several publications that go over proper pruning and maintenance of trees, both before a storm and after recovery.
Live oaks have dense wood and are extremely wind-resistant species. Photo credit: Carrie Stevenson, UF IFAS Extension
This chart developed by UF researchers denotes the percentage of trees surviving Hurricane Ivan, by species. Courtesy M. Duryea and E. Kampf
Live oaks, and sand live oaks (which live on coastal sand dunes) are slow-growing trees with extraordinarily dense wood. This protects them in hurricane-force winds. Part of the working theory on why bald cypress, holly, and magnolia do well in storms is their pyramidal shape, which seems to allow wind to whip circularly around the trees and avoid damage. Sabal palms are botanically considered part of the grass category and not trees, so their single, flexible trunk allows them to handle the onslaught of wind. Sweetgums are particularly hardy in tornadoes, due to their sturdy root system and shorter, “stout” branches. Smaller understory trees like crape myrtle and dogwood are likely dodging the strongest winds, but also have strong branch structures and dense wood. These two species, along with sand live oak, also lost an average of more than 80% of their leaves. This defoliation is an adaptation to heavy winds, with trees that lost leaves performing better overall than species that held onto their leaves but toppled at the trunk.
Significant damage to a home after a tornado struck Pensacola in 2016. Photo credit: Carrie Stevenson, UF IFAS Extension
Another list of tree survivability was developed for residents in tropical and subtropical regions of the state. If you have friends or family in south-central Florida, be sure to share this information with them.
Besides planting wind-resistant species, the research team shared other observations related to tree planting and arrangement, too. Single trees are more vulnerable than trees planted in clusters, as they protect each other from incoming winds. Older trees, and those with preexisting damage, are more likely to fall. Trees with plenty of space around their roots do better—if a tree is surrounded on two or more sides with buildings or other hard surfaces, they cannot spread adequately. Detailed information on identifying damaged or poorly structured trees, along with maintenance and pruning tips, can be found in the “Urban Forest Hurricane Recovery Program” series of articles written by the UF tree specialists involved in the studies. The publications include good diagrams and photos of specific examples.
There are often questions about who is responsible when storm-damaged trees end up on a neighbor’s property. UF IFAS Escambia County Extension discusses a few common situations using legal interpretations from the UF publication HANDBOOK OF FLORIDA FENCE AND PROPERTY LAW: TREES AND LANDOWNER RESPONSIBILITY.
Stoke’s aster ‘Mel’s Blue’ 20 days after Hurricane Sally’s landfall. Notice how soil was washed away from root ball, all the leaves emerged post-hurricane. Photo credit: Mary Salinas, UF/IFAS Extension.
Hurricanes can wreak havoc in your landscape, but they can also reveal what plants are the toughest and most resilient. It’s a great learning opportunity.
A few weeks ago, Hurricane Sally came along and brought about 10 feet of surge and waves across my landscape and completely covered everything except the tallest trees for about 18 hours. (Fortunately, our house is on stilts and we did not have intrusion into our main living areas.)
As expected, the trees, including Dahoon Holly and Sweetbay Magnolia, took a beating but stayed intact. With their dense fibrous root system, most of the clumping native grasses also stayed put.
Perennial milkweed 3 weeks post-hurricane. New topsoil and compost now covers the rootball. Photo credit: Mary Salinas, UF/IFAS Extension.
The most surprising plant species that survived were about a dozen Stoke’s aster and 3 perennial milkweed. 4-5 inches of soil all around them was washed away, most of the roots were exposed, and the leaves were stripped or dead. The other perennials that had lived nearby were all washed away. To my surprise, within about 10 days after the storm, these two plant species started poking up new stems and leaves.
Here’s a list of some of the plants either in my yard or in the neighborhood that survived Hurricane Sally’s storm surge and may be suitable to add to your coastal landscape:
Dahoon holly, Ilex cassine
Muhly grass, Muhlenbergia capillaris
Dwarf Fakahatchee grass, Tripsacum floridanum
Perennial milkweed, Asclepias perennis
Stoke’s aster, Stokesia laevis, specifically the cultivars ‘Mel’s Blue’ and ‘Divinity’
Bottlebrush, Callistemon citrinus
Gardenia, Gardenia jasminoides
Bougainvillea, Bougainvillea spp.
Flax Lily, Dianella tasmanica
Crapemyrtle, Lagerstroemia spp.
Cabbage palm, Sabal palmetto
Canary Island date palm, Phoenix canariensis
Sweetbay magnolia, Magnolia virginiana
Augustinegrass, Stenotaphrum secundatum
And, unfortunately, the rhizomes of the invasive torpedograss also survived.
For more information on salt tolerant and hurricane resistant plants, see:
7 year old Overcup Oak (Quercus lyrata) on the edge of a wet weather pond in Calhoun County. Photo courtesy of Daniel Leonard.
Haunting alluvial river bottoms and creek beds across the Deep South, is a highly unusual oak species, Overcup Oak (Quercus lyrata). Unlike nearly any other Oak and most sane people, Overcups occur deep in alluvial swamps and spend most of their lives with their feet wet. Though the species hides out along water’s edge in secluded swamps, it has nevertheless been discovered by the horticultural industry and is becoming one of the favorite species of landscape designers and nurserymen around the South. The reasons for Overcup’s rise are numerous, let’s dive into them.
First, much of the deep South, especially in the Coastal Plain, is dominated by poorly drained flatwoods soils cut through by river systems and dotted with cypress and blackgum ponds. These conditions call for landscape plants that can handle hot, humid air, excess rainfall, and even periodic inundation (standing water). It stands to reason our best tree options for these areas, Sycamore, Bald Cypress, Red Maple, and others, occur naturally in swamps that mimic these conditions. Overcup Oak is one of these hardy species. Overcup goes above and beyond being able to handle a squishy lawn, it is often found inundated for weeks at a time by more than 20’ of water during the spring floods our river systems experience.
The same Overcup Oak thriving under inundation conditions 2 weeks after a heavy rain. Photo courtesy Daniel Leonard.
The species has even developed an interesting adaptation to allow populations to thrive in flooded seasons. Their acorns, preferred food of many waterfowl, are almost totally covered by a buoyant acorn cap, allowing seeds to float downstream until they hit dry land, thus ensuring the species survives and spreads. While it will not survive perpetual inundation like Cypress and Blackgum, if you have a periodically damp area in your lawn where other species struggle, Overcup will shine.
Overcup Oak is also an exceedingly attractive tree. In youth, the species is extremely uniform, with a straight, stout trunk and rounded “lollipop” canopy. This regular habit is maintained into adulthood, where it becomes a stately tree with a distinctly upturned branching habit, lending itself well to mowers and other traffic underneath without having to worry about hitting low-hanging branches. The large, lustrous green leaves are lyre-shaped if you use your imagination (hence the name, Quercus lyrata) and turn a not-unattractive yellowish brown in fall. Overcups especially shines in the winter, however, when the whitish gray, shaggy bark takes center stage. Overcup bark is very reminiscent of White Oak or Shagbark Hickory and is exceedingly pretty relative to other landscape trees that can be successfully grown here.
Overcup Oak leaves in August. Note the characteristic “lyre” shape. Photo courtesy Daniel Leonard.
Finally, Overcup Oak is among the easiest to grow landscape trees. We have already discussed its ability to tolerate wet soils and our blazing heat and humidity, but Overcups can also tolerate periodic drought, partial shade, and nearly any soil pH. They are long-lived trees and have no known serious pest or disease problems. They transplant easily from standard nursery containers or dug from a field (if it’s a larger specimen), making establishment in the landscape an easy task. In the establishment phase, defined as the first year or two after transplanting, young, transplanted Overcups require only a weekly rain or irrigation event of around 1” (wetter areas may not require any supplemental irrigation) and bi-annual applications of a general purpose fertilizer, 10-10-10 or similar. After that, they are generally on their own without any help!
Typical shaggy bark on 7 year old Overcup Oak. Photo courtesy Daniel Leonard.
If you’ve been looking for an attractive, low-maintenance tree for a pond bank or just generally wet area in your lawn or property, Overcup Oak might be your answer. For more information on Overcup Oak, other landscape trees and native plants, give your local UF/IFAS County Extension office a call!
As Hurricane Michael was barreling through the Panhandle region, wasp populations were at their highest of the year. Winds and flooding destroyed many of the nests of paper wasps, hornets, and yellow jackets and now wasps may be aggressive as they defend themselves or remnants of their nests. All are capable of multiple stings that are very painful. It is very likely that you will encounter stinging wasps as they scavenge for food and water, as well as seek shelter among debris and exposed trash.
Many people are stung by paper wasps after storms. They are not attracted to traps.
Here are a few pointers to help deal with stinging wasps.
Try not to swat at wasps flying around or landing on you. You may be less likely to receive a sting if you can flick them off.
Some wasps are attracted to the sap from broken or recently cut trees. Look before you reach. Wear gloves and other protective clothing when moving debris in case you disturb foraging or nesting activities.
Wasps are also attracted to sugars and water. Try your best to keep food and drink cans covered. Completely close garbage containers or bags that contain food debris.
Repellents are not effective against wasps. There are pesticides labeled to spray on smaller paper wasp nests if you find one in a spot close to people’s activity. These are usually aerosol pyrethroids or pyrethrins. Make sure you read the label carefully and use the product as directed.
Do not use non labeled products like gasoline to manage wasps. This is not only illegal but can be dangerous to yourself and the environment.
There are traps for yellowjackets that you may purchase or make. These only manage those wasps flying around, not any remaining in a ground nest.
Here is a Do It Yourself Yellowjacket trap from UF IFAS Extension.
Cut the top 1/3 off your 2 liter bottle so that you have 2 pieces.
Add a bait (fermenting fruit or beer) to the bottom of the plastic bottle.
Invert the top portion of the bottle into the base, forming a funnel.
Hang or place traps so they are about 4 to 5 feet above the ground. For safety, place them away from people.
A homemade trap to catch yellowjackets. Photo by Alison Zulyniak
A natural disaster such as Hurricane Michael can cause excess standing water which leads nuisance mosquito populations to greatly increase. Floodwater mosquitoes lay their eggs in the moist soil. Amazingly, the eggs survive even when the soil dries out. When the eggs in soil once again have consistent moisture, they hatch! One female mosquito may lay up to 200 eggs per batch . Standing water should be reduced as mush as possible to prevent mosquitoes from developing.
You should protect yourself by using an insect repellant (following all label instructions) with any of these active ingredients or using one of the other strategies:
DEET
Picaridin
Oil of lemon eucalyptus
Para-menthane diol
IR3535
An alternative is to wear long-sleeved shirts and pants – although that’s tough in our hot weather
Wear clothing that is pre-treated with permethrin or apply a permethrin product to your clothes, but not your skin!
Avoid getting bitten while you sleep by choosing a place with air conditioning or screens on windows and doors or sleep under a mosquito bed net.
Now let’s talk about mosquito control in your own landscape.
Let’s first explore what kind of environment in your landscape and around your home is friendly to the proliferation of mosquitoes. Adult mosquitoes lay their eggs on or very near water that is still or stagnant. That is because the larvae live in the water but have to come to the surface regularly to breeze. The small delicate larvae need the water surface to be still in order to surface and breathe. Water that is continually moving or flowing inhibits mosquito populations.
Look around your home and landscape for these possible sites of still water that can be excellent mosquito breeding grounds:
bird baths
potted plant saucers
pet dishes
old tires
ponds
roof gutters
tarps over boats or recreational vehicles
rain barrels (screen mesh over the opening will prevent females from laying their eggs)
bromeliads (they hold water in their central cup or leaf axils)
any other structure that will hold even a small amount of water (I even had them on a heating mat in a greenhouse that had very shallow puddles of water!)
You may want to rid yourself of some of these sources of standing water or empty them every three to four days. What if you have bromeliads, a pond or some other standing water and you want to keep them and yet control mosquitoes? There is an environmentally responsible solution. Some bacteria, Bacillus thuringiensis ssp. israelensis or Bacillus sphaericus, only infects mosquitoes and other close relatives like gnats and blackflies and is harmless to all other organisms. Look for products on the market that contain this bacteria.
