Several times each month I am diagnosing shrub and tree problems in Escambia County that are related to the same issue, improper planting. Symptoms of this problem can be slow growth, leaf browning, and dieback. Sometimes under stressful weather conditions like drought, plants completely die.
The trunk was covered with several inches of soil. Photo by Beth Bolles, UF IFAS Extension Escambia County. Shrub stems should never be below the soil level. Photo by Beth Bolles, UF IFAS Extension Escambia County.
This is a difficult sight for homeowners who have invested time and money in a tree or shrub to enhance the landscape. In some cases, the planting issues can be fixed but there are other times when a new plant will need to be installed.
The good news for homeowners is that this is a completely preventable issue. The University of Florida has excellent publications with photos about installing and caring for trees and shrubs. My Panhandle colleagues and I have also shared numerous articles and videos on proper plant installation.
Care must be taken during installation to set your plant at the correct depth. Even if a landscaper or nursery is installing the plant for you, check their work. Make sure the rootball is cut or sliced, it is not set below grade, that any straps holding the rootball are cut after it is set, and proper backfilling occurs without soil over the top of the rootball.
You don’t want to find out later in the season or even year’s later that your plant declined just because of planting problems.
Many future problems can be avoided by paying attention to tree selection, planting and maintenance in Florida’s high wind climate. We may think of tropical storms causing tree damage but our typical summer thunderstorms can produce winds in excess of 50 miles per hour with downbursts reaching over 100 mph.
There is no way to protect trees from all storm damage. Trees are not adapted to worst-case storms, such as Hurricanes Michael or Ian, only to our average wind climate.
It’s wise to take time to select and correctly plant the right trees for North Florida.
Past hurricanes have taught us that large growing trees planted too close to curbs, sidewalks or buildings blow over easily because they don’t have adequate room to develop a sound root system. It’s best to either plant these trees farther away, plant trees that may stay small, or increase the size of space allocated for tree root growth.
Research and storms have taught us that tree roots need large soil spaces for strong, stable growth. The more rooting space trees have, the less likely they are to fail. Strong root growth is essential for tree stability and health. Large maturing trees need at least 30 feet by 30 feet (900 ft. sq.) of rooting space. Many construction practices such as paving over roots, raising and lowering soil grade, and soil compaction from equipment result in root injury for existing trees, making them less durable and less stable.
Magnolia Tree in the Landscape. Photo courtesy Stephen Greer
Studies have also shown that trees growing in groups better survive high winds compared to individual trees. A group was defined as five or more trees growing within ten feet of another tree, but not in a row.
A short list of large maturing, storm resistant trees to consider include live oak, sand live oak, bald cypress, pond cypress, black gum and magnolia.
Do some homework and take a look at tree species that have done well in your area. If you don’t want or need a large tree in your yard, there are many small and medium sized wind-resistant trees from which to choose, like Crape Myrtle and Vitex. Many palms are wind resistant too, particularly the cabbage palm.
Having success with trees in the landscape involves starting with healthy, well-developed trees. Plant the right tree in the right place. Follow good planting procedures, including not planting trees too deep and providing adequate root space to allow for strong, healthy root growth. Practice correct maintenance techniques, which includes learning how to prune to produce a structurally sound tree. Finally, consider if it is time to be proactive and have large over-mature, declining trees removed and replaced before the next storm.
There are numerous insects and insect relatives that can produce webbing, and webbing can be a sign that something unwanted is near. Arachnophobes might grow uneasy at the sight of a spiderweb, and gardeners might frown to see the tiny filaments that spider mites spin. Tree lovers might assume that webs on a tree are a sign that caterpillars such as the eastern tent caterpillar have taken up residence. But what about webs on a tree trunk?
Bark louse webbing. Photo courtesy of Evan Anderson.
If you come across a tree trunk coated in silk, chances are you’re looking at the work of a bark louse. Also known as psocids or tree cattle, these little insects eat all the stuff that sticks to a tree’s bark. Lichen, moss, algae, and dead bark can all end up as meals for a hungry bark louse. The good news is that while lichens don’t hurt trees, neither do bark lice!
Bark lice spin their webbing as protection from predators. They often produce large quantities of webbing, because there are often large quantities of bark lice present. The name ‘tree cattle’ comes from the fact that they form these large colonies, and move in a manner similar to cattle in groups. While swirling swarms of creepy-crawlies rarely make people feel at ease, don’t worry about these. Acting as a sort of clean-up crew, they will do their work, grow and mature, and move elsewhere by themselves.
There are often several generations of bark lice each year in Florida, so they may reoccur. No control is needed for these insects, though if leftover webbing is considered aesthetically unpleasing it can be removed by spraying with a sharp jet of water. For more information about bark lice, see our EDIS publication at https://edis.ifas.ufl.edu/publication/IN553.
Bark louse nymph. Photo courtesy of Evan Anderson.
There are many considerations to make when landscaping with small trees (under 20 feet) in the landscape that are not suitable for large trees. Some of the trees discussed can at times be considered large shrubs depending on definitions and opinions. For the purpose of this article, if it reaches 15 to 20 feet consider it a tree.
Choosing small trees for the right setting involves a number of reasons that could include the need for more privacy from other homes, use as a sound barrier from busy roads, hiding your utility area of the landscape or something unattractive nearby and making sure power lines are not obstructed. Other considerations might include soil types, drainage and holding capacity of the soils, irrigation needs, rate of plant growth and maturity height at 20 feet. Below are a few to consider for the Panhandle of Florida.
Little Gem Magnolia (Magnolia grandiflora ‘Little Gem’) and Teddy Bear Magnolia (M. grandiflora ‘Teddy Bear’) are strong hardy plants once established (within the first 6 months to a year). Both are evergreen with dark green foliage. The ‘Little Gem’ will grow to 20 feet tall by 15 to 18 feet wide. As it matures it tends to become more open and less dense which adds a nice character to show parts of the lower limbs. The ‘Teddy Bear’ will grow to 18 to 20 feet tall but at an even slower rate of maturity to 12 to 15 feet wide while maintaining its density of foliage from bottom to top. It may take a little work to locate the ‘Teddy Bear’ Magnolia.
Photo courtesy: Stephen Greer Teddy Bear Magnolia (Small compact grower)
Several hollies to consider would include the Cassine Holly ‘Tensaw’ (Ilex cassine ‘Tensaw’) and American Holly (Ilex opaca). Both are evergreen and produce red berries during the fall that are bird favorites. They have similar heights of 15 to 20 feet and widths of 10 to 12 feet. Pruning can assist in shaping and slowing these measurements, but keep in mind this will change the look of the tree and create a more formal plant presentation.
Photo courtesy: Stephen Greer Cassine Holly ‘Tensaw’
The Fringe Tree (Chionanthus virginica) has been a popular tree southeast U.S. for many years. It brings a bright spot to the landscape with white flower panicles that cover the tree in mid to late spring depending on location. For a full color effect, plant it with an evergreen hedge behind it. This oval deciduous tree will grow to 12 to 20 by 10 to 15 wide. The dark blue fruit appears in the fall and serves as good bird food source. This fruit is usually hidden behind the foliage. There might even be a nice yellow leaf change in the fall if temperatures and weather allow.
The Oracle of Omaha, Warren Buffett, once said “Someone is sitting in the shade today because someone planted a tree long ago.” While that’s all fine and good and I’m happy that the next generation gets to enjoy the things we grew, most of us would like to enjoy shade in our lifetimes too! If you too want to plant your own shade, one of the best rapidly growing shade tree choices for the Panhandle is the majestic Florida native Green Ash (Fraxinus pennsylvanica).
Green ash trees have a vase shape form. Photo Credit: University of Florida/IFAS
Green Ash is a large (50-100’ tall), oval-shaped, deciduous shade tree native to the entire eastern half of North America, but best of all for those of us craving shade, it grows to its mature height in a relative hurry. While most trees that grow extremely fast tend to be inherently weak and short-lived, this is not the case with Green Ash. Capable of growing 6-10’ in a single year if irrigated and fertilized appropriately and often living well over 100 years, there aren’t many plants in the Panhandle that grow quicker or live longer.
There’s much more to Green Ash than growth rate and life span, however. The tree is also one of the prettiest around. Come on, you didn’t think I’d recommend an ugly plant, did you? A look up into the canopy at different times of the year and one can see the tree’s deep, dark green foliage, good-for-Florida yellowish fall color, and slightly showy light green seed pods. Below, the straight trunk is laced with distinctive diamond-shaped bark that hints at the extremely high-quality wood underneath. Fun fact, Ash is historically the most popular wood used to make baseball bats due to its hardness at a relatively light weight – more MLB home runs have been hit with Ash than any other species!
The compound leaf of a green ash tree. Photo Credit: University of Florida/IFAS
As a Florida-Friendly plant, Green Ash is fairly low-maintenance and provides many environmental services. The species, like any other plant, requires supplemental water and fertilizer during the establishment period, generally the first year or so after planting, but doesn’t demand much else from gardeners after that. Green Ash specimens in Florida also don’t have much in the way of pest problems (the invasive Emerald Ash Borer has devastated ash populations in northern states but thankfully has not yet been found in Florida). However, as a host plant for several native pollinators, including the Eastern Tiger Swallowtail, Mourning Cloak, Orange Sulphur, and Viceroy Butterflies, you may occasionally find caterpillars munching away on the tree’s foliage. If you can handle a little leaf damage, try to leave any caterpillars alone and enjoy the stunning butterflies they later morph into!
Green Ash is a beautiful, ultra-adaptable shade tree. Though the species prefers moist areas, there aren’t many sites the tree can’t thrive in. Do you have a low-lying area near a swamp or stream that stands in water from time to time? Great! Green Ash will thrive. Do you need a street tree to survive in a harsh environment with a cramped root zone surrounded by concrete? Green Ash will be right at home there as well. Green Ash is simply a classic shade tree with many interesting attributes that improves the look of any landscape it occupies. Plant one today!
For more information about Green Ash, other shade tree species, or any other horticultural/agricultural topic, contact us at the UF/IFAS Calhoun County Extension office.
