by Mark Tancig | Nov 8, 2018
Trees have a pretty bad reputation in north Florida these days. They’re on our homes, cars, streets, power lines, and all over the yard causing a lot of grief. While my heart goes out to all of those dealing with trees in places they shouldn’t be, now’s a good time to remember all the reasons we should want trees around. It’s also a good time to review how to minimize tree impacts from future storms.
An older, poorly branched loblolly pine in Tallahassee. Credit: Mark Tancig
Benefits of Trees
Beyond being a huge source of oxygen, necessary for many organisms to live, trees provide other benefits such as well. According to a recent analysis of Tallahassee’s urban trees, approximately three million pounds of pollutants, such as carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide, and particulate matter, are reportedly removed each year. The same report calculated that half a billion gallons of precipitation was intercepted by these trees rather than becoming stormwater runoff, reducing impacts of erosion and non-point source pollution. These trees also saved citizens an estimated one million dollars. Total annual benefits to the citizens was over $15 million per year! Researchers have found that trees increase residential or commercial property values an average of 7%!
Ways to Minimize Tree Failure
Select Replacement Trees Wisely
While very few trees could make it through sustained winds of 155 mph, replanting trees sooner will help communities see the benefits mentioned above and help them return to their former beauty. Even the most wind-resistant trees are likely to fail in a storm like Hurricane Michael. UF/IFAS researchers have studied wind-thrown trees following hurricanes and have found these trees to be some of the most wind-resistant – hollies (Ilex spp.), southern magnolia (Magnolia grandiflora), live oak (Quercus virginiana), cypress (Taxodium spp.), cabbage palm (Sabal palmetto), and, interestingly, sparkleberry (Vaccinium arboreum).
The least wind-resistant trees include pecan (Carya illinoiensis), tulip poplar (Liriodendron tulipifera), laurelcherry (Prunus caroliniana), laurel oak (Quercus laurifolia), water oak (Quercus nigra), southern red oak (Quercus falcata), red cedar (Juniperus virginiana), pines (Pinus spp.), and Chinese elm (Ulmus parvifolia).
When replanting, consider planting at least three trees in a group rather than an individual tree, as researchers found that trees in groups fared better.
An older water or laurel oak. Credit: UF/IFAS.
Tree Care
With existing trees and newly planted trees, taking good care of the tree can help it withstand high winds. In addition to proper pruning techniques and providing adequate root zone space, paying close attention to minimize soil compaction and root zone disturbances will help create a stronger root system. Older trees should be regularly monitored for potential signs of decay.
An older oak with decay in trunk. Credit: UF/IFAS.
UF/IFAS has many great resources related to tree health and recovery after hurricanes. A search for Urban Forest Hurricane Recovery Program at our EDIS website (https://edis.ifas.ufl.edu) has several publications to help decide how to move forward and create a healthy urban forest. Let’s not allow our frustration with the tree on the roof to prevent us from recognizing that trees are good.
by Larry Williams | Oct 20, 2018
Partly uprooted tree from hurricane. Photo credit: Larry Williams
Hurricane damaged plants should be cared for as soon as possible. Partially uprooted small trees and shrubs should be securely staked in their original positions. Until plants are reset, protect exposed roots and prevent drying. Soil, moist burlap sacks or moist sphagnum moss can be put on exposed roots. Remove damaged roots so the tree can be reset at ground level.
Once reset, trees should be secured. Two or three, four-foot long, 2 x 2 inch wood stakes can usually anchor trees with trunk diameters less than two inches. Stakes should be placed about a foot outside root ball and inserted eighteen inches into soil. Secure stakes to trunk with ties made from wide, smooth material or hose-covered wire. Trees two inches or larger in diameter should be guyed with three or four wires or cables. Guy wires are secured to deeply driven short stakes evenly spaced outside the root ball. Guy wires should be run through rubber hose and secured to trunk at only one level. Mark support wires with bright materials to prevent accidents.
Guy wires should be adjusted several times during growing season to minimize trunk injury. Support stakes and wires should stay in place for one year.
Soil should be filled around root area once the tree is staked into position. Firm around roots to eliminate air pockets and provide support. Excess soil over the normal root area can be damaging. Only replace soil that has been washed or worked away from roots.
In cases where all branches were destroyed, remove the tree. This is especially important for trees such as pine that do not normally regain their natural form. You may be able to keep other trees such as oaks, where strong bottom limbs still exist. However, emerging sprouts from ends of large, cut limbs will be poorly secured to the tree and are likely to fall from the tree during a storm. In addition, decay organisms usually enter these large wounds. Trees and shrubs that lost their leaves from high winds can usually be saved and should resume growth.
Any tree work, including tree removal should be done by a professional arborist, preferably a certified arborist. To find a certified arborist in your area contact the International Society of Arboriculture (ISA) at 217 355-9411 or at http://www.isa-arbor.com/. You also may contact the Florida Chapter of ISA at 941-342-0153 or at http://www.floridaisa.org/.
Reset plants should be watered twice a week and fertilizer should not be applied. Until re-established, fertilizer will be of no benefit and may injure new roots.
Plants exposed to saltwater, including lawns, should be irrigated with fresh water as soon as possible. Apply water more frequently than under normal conditions.
For additional information, visit http://sfyl.ifas.ufl.edu/disaster-prep-and-recovery or contact the UF/IFAS Extension Office in your county.
by Matthew Orwat | Sep 13, 2018
Bare limb tips and clusters of webbing in pecan trees are often the first sign that fall is right around the corner.
This webbing is caused by clusters of the larvae of the Fall Webworm (Hyphantria cunea (Drury)) which is often also called Pecan Webworm. “Fall Webworm” is a bit of a misnomer in our region since they are able to strike in spring and summer thanks to our long growing season. They are most noticeable in the fall thanks to cumulative effects of earlier feeding.
The adult form of the fall webworm is a solid white or white and brown spotted moth that emerges in late March through August in southern climates. After mating they lay orderly clusters of green eggs, usually May through August. Soon after emergence, the larvae begin creating silk webs to protect themselves as they voraciously feed on their various host plants, of which Pecan is most common in Northwest Florida gardens.
Although they are capable of defoliating complete trees, especially smaller ones, most seasons they are kept in check by beneficial insects such as the paper wasp. It is beneficial for small orchards or home growers to scout their trees from June through August. If small webs are observed in young trees, it is best to prune them out with a pole saw or pole pruner and dispose of the branch. Pruning of small branches does not harm the tree, but it may be of no benefit to remove small webs in larger trees, if they are being controlled by natural enemies.
Most home gardens don’t have a practical ability to spray for this insect. For homeowners it is difficult to spray for control, due to the cost of the equipment required to get the spray into the tree canopy. If spraying is an option, many insecticides containing spinosad or Bacillus thuringiensis (Bt) exist. Both of these products target caterpillars while not harming beneficial insect predators that feed on these worm populations. Several more toxic insecticide products exist that will control fall webworm, but they often exacerbate insect problems by killing off beneficial insects that might be controlling other insect pests.
Fall webworm is not usually a serious problem for home gardens. Let natural enemies take care of the problem in most cases.
Supplemental Material:
by Mark Tancig | Mar 26, 2018
How many times have you pulled up to an intersection and couldn’t see oncoming traffic because a shrub was in the way? It’s frustrating, and unsafe. To help each other out, we should all pay attention to landscape plants that may be blocking the view of oncoming traffic and/or pedestrians, including your own driveway. Keeping a clear sight distance doesn’t mean you need a moonscape, but proper planning and maintenance of the landscape can look good and keep a clear sight distance.
“Site distance” is what traffic engineers call being able to see driving lanes and sidewalks, in both directions. I knew engineers had such a term and assumed they would have a precise way to measure it. Of course, since they’re engineers, they did. A local traffic engineer with the Leon County Public Works Department sent me the sketch. The figure should help, but, basically, you need to think of it as a sight triangles. The three points in each triangle are 1) the driver’s location at an intersection stop (where triangles meet), 2) the centerline of each lane, and 3) a point 300 – 500 down each lane. To determine if the view is clear, stand where a driver would stop, and approximate the height of the driver’s eye.
Please be safe as you rush to measure!
I can’t see if anyone’s coming! Credit: Mark Tancig/UF IFAS.
If you have vegetation in the way, assess the situation. First thing to determine is what plant(s) you have. If you don’t know, send a photo to your local Extension Office. Next, determine if the identified plant(s) can be pruned to get out of view and/or below the height of the driver’s eye. Transplanting to another location is a possibility, if it’s a plant that transplants well and isn’t too large. Otherwise, removing and replacing is the best option for the safety of the community.
When needing a low-growing replacement, consider the following Florida-Friendly plants:
African Iris (Dietes vegata) – Part Sun/Shade
Black-eyed Susan (Rudbeckia spp.) – Sun
Blue-eyed grass (Sisyrinchium angustifolium) – Part Sun/Shade
Butterweed (Packera glabella) – Shade
Coontie (Zamia florida) – Sun – Shade
Lily of the Nile (Agapanthus orientalis) – Part Sun/Shade
There are many, many more plants to choose from, including dwarf varieties of common ornamental plants. Your local Extension Office can help provide resources to help you make a good choice. Online resources, such as the Florida-Friendly Landscaping Pattern Books and the Guide to Plant Selection and Landscape Design, are also available.
by Daniel J. Leonard | Feb 2, 2018
It is a common misconception that winter is a time of rest in the landscape, for both plants and people. In the Panhandle, the winter months tend to be rainy and miserable, with wild weather fluctuations in between. These conditions cause folks to think their chores are done until the weather warms up and plants begin to grow again. In reality, winter lays the foundation for the next year of growth! This is because, though most plants are dormant or have at least slowed their growth above ground, their root systems continue to develop through the cold. This “catch-up” time when plants are not growing above ground is the ideal time to plant woody trees and shrubs so they can focus their energy on getting a root system established without having to worry about supporting shoot growth! However, even if you plant at the proper time, several common mistakes can still torpedo your planting efforts. I once worked for a snarky nurseryman who, when new employees would ask how he wanted trees to be planted, would answer, “Green side up, of course.” So, remember to plant green side up and also keep the following in mind when you plant this winter!
Cutting circling roots.
- Digging the right hole. The quickest way to resign a plant to failure before even removing it from the container is to dig a bad hole. In order to facilitate ideal root development and allow the plant to establish as rapidly as possible, the planting hole should be 2-3 times the diameter of the rootball. The easiest way to measure this is to set the plant were you want it and begin digging the hole around it; this step allows you to visualize the size of the hole. Most holes that are “eyeballed” are not wide enough. A little extra digging in the beginning can make a lot of difference later. In addition, the planting hole should be, at minimum, the same depth as the rootball. In a perfect scenario, after planting, the top of the rootball should be a half an inch to an inch higher than the surrounding soil to accommodate for settling of the soil underneath the rootball. This prevents the plant from sitting in a depression that water could pool in, leading to disease issues. It can be hard to believe, but simply digging a proper hole helps ensure plant establishment and enables long-term survival!
- Preventing Circling Roots. Often, plants are constrained in a container that is a little too small for a little too long on the floor of a nursery. When this situation occurs, the roots of the plant do not stop growing once they reach the “wall” of the container, but rather keep going in a circular pattern around the edge of the pot. This is a problem because, if not corrected, the roots will continue this growth pattern once in the ground, eventually strangling the plant. However, this problem is easily corrected by severing the circling roots. This is where gardeners often get squeamish however. It is time to check your plant conscience at the door and know the plant will thank you later! I like to make vertical slices, evenly spaced, around the rootball. These slices should cut about an inch into the rootball to ensure both superficial and unseen circling roots are cut; this somewhat brutal task can be accomplished with a sharp shovel, machete, or even a heavy-duty pair of pruners. At every cut, the previously circling root will branch, creating a nice web of new roots that will serve as anchors for the fledgling plant.
Backfilling Correctly. The single most asked question involving plants trees and shrubs is, “Should I backfill the hole with compost?” The single most common answer I give in return is, “Absolutely not.” Although it seems counterintuitive, it is almost never a good idea to backfill with a soil that is not your native soil. There is a simple reason for this. If a tree were planted in a hole that is backfilled with rich soil and is surrounded by our infertile, native Florida sands, why would it ever want to leave that hole? Turns out, it does not want to leave that easy environment because it has all the nutrients it needs right there, which is a problem. What happens when a drought, hurricane, or other stress event comes calling? The plant will not have a wide-spreading root system for support and will suffer from lack of water or lodging from high winds. By backfilling with your native soil, you encourage the plant’s roots to grow out and seek water and nutrients.
As you can see, there is a little more to planting than “green side up.” But, if you plant at the right time, dig the right hole, prevent circling roots, and backfill with your native soil, you will have set your newly bought tree or shrub up for success and will be able to enjoy it for many years to come! For more information on planting and other horticultural topics, contact your local UF/IFAS Extension office and as always, happy gardening!
