What is Drilling Holes in My Trees?

What is Drilling Holes in My Trees?

They are often very prevalent on trees in our area; a strange string of shallow holes drilled in the bark of a tree. Often this is oozing sap, especially on pines and hardwoods with heavy sap flow, and more holes keep appearing as the sap dries up in others. I get calls and questions all the time about this strange phenomenon and what can be done about it. The calls are usually from homeowners with a prized backyard tree, but I get calls from farmers with orchard crops and other settings as well. What is causing this strange attack on these trees? What drills near perfect holes just into the sapwood of a tree? The answer is a bird of all things; and in particular the yellowbellied sapsucker (Sphyrapicus varius). This small to mid-sized bird is in the woodpecker family and has the peculiar diet of feeding on sweet and nourishing tree sap; as well as small insects attracted to and trapped into the sap. This little native bird drills and taps trees for sweet sap. Much like we humans do with maple trees up north for syrup production. They then visit their trees and drink the sap until the tap dries up and then drill another hole. This pattern of feeding leaves this banding of holes drilled on the tree, and they drill deep enough that it will be visible for quite a long time often permanently.

Yellowbellied Sapsucker damage on an American Sycamore-Walton County, FL Photo Credit: Ian Stone

The biggest question most people want answered, beside what is doing/causing this, is will this hurt the tree? The best answer to that is mostly no, but with all things tree related it depends. On young and smaller trees, particularly newly planted ones, the feeding can stress the tree and can cause some issues. The biggest risk is that if the sapsucker drills in a complete ring around the trunk, something more common on smaller trees, they could cause the tree to be girdled and killed. Another issue is that their feeding can attract pests and disease, such as bark and wood boring beetles along with some fungal infections of the open wounds. These pest and diseases may then go on to cause severe damage and death, especially if the tree is stressed by drought or other environmental factors. Ultimately, the feeding of the yellowbellied sapsucker rarely kills or severely damages trees by itself. Most of the time it just causes unsightly damage, and the bark damage and subsequent healing over can cause an unsightly area of bark. This is especially true on thin barked trees that have smooth bark, such as beech, magnolia, and birch.

You are probably wondering how to prevent this damage in the first place or stop it once a sapsucker takes a liking to your tree. The best thing to do is to make some changes in your landscape to prevent attracting sapsuckers and/or scare them away if they are in the area. Your first step is to learn to identify the yellowbellied sapsucker, so you can tell if they are in the area. Yellowbellied sapsuckers are a woodpecker and to many they look like several of our other small woodpeckers such as the downy, red-cockaded, and possibly even the red bellied. They look the most like a slightly larger downy woodpecker with more red on their heads. Males are the most brightly colored and have a read crown and throat patch, while females have the red crown only. The back and wings are black and white, and have somewhat of a ladder appearance on the back. They are smaller birds, around 7-8 in. in length, similar in size to a robin or cardinal. They cling to the bark and shuffle up and down the tree like other woodpeckers. The namesake yellow belly is faint and difficult to see at a distance without binoculars or other aids

Yellowbellied Sapsucker (Sphyrapicus varius) side profile Photo Credit:  Johnny N. Dell, Bugwood.org

If you notice yellowbellied sapsuckers in your area, you can watch them to see which trees they seem attracted to. Once you identify the portion of your yard they seem to like; you can put up windsocks or predatory statues to scare them away. This is the most effective method to keep these somewhat pesky birds out of an area and stop the tree damage. It also does not harm the birds or any other wildlife, though it may scare away birds that you would like to stick around. You may see some information about putting up hardware cloth or metal sheeting around the trunk of the tree. This is not a good method and often it does not stop the sapsuckers, who simply find another unguarded portion of the tree or work around the exclusion device. Using hardware cloth or sheeting can also damage the tree worse than the sapsucker’s feeding activity, and if not properly installed and consistently loosened they can even girdle and kill a tree. If you are having trouble with the interesting but pesky birds, use the scare away method consistently until they leave the area. If they believe predators are in the area and regularly startled while feeding they usually leave for a better feeding area pretty quickly.   

The Franklin Tree

The Franklin Tree

In the late 1700’s, explorer and naturalist William Bartram and his father, the “King’s Botanist”—visited Pensacola and much of the southeastern United States. Curious observers of everything from plant growth and wildlife to Native American culture, they were also collectors. Countless American plant species were sent to Europe for further examination and later preserved in gardens and arboretums.

The Franklin tree no longer grows in the wild, but was originally discovered and named in the late 18th century near this spot in coastal Georgia. Photo credit: Carrie Stevenson, UF IFAS Extension

If it were not for their formidable observation skills, at least one species of unique native tree would be completely extinct. While traveling along the Georgia coast in 1765, the Bartrams recorded and named a species of small tree they’d never seen anywhere before. They christened it the “Franklin tree” for their friend and compatriot Benjamin Franklin. Known scientifically as Franklinia alatamaha (after Franklin and the nearby Altamaha River), its similarity to the loblolly bay tree landed it in the Gordonia genus for a while. References in the literature to this tree may include Gordonia alatamaha, Gordonia pubescens var. subglabra, or Lacathea florida, although it is now officially Franklinia alatamaha and considered part of the tea tree family.

The attractive bloom of the Franklin tree is reminiscent of magnolia flowers. Photo credit: Scott Zona, used with permission from NCSU Extension

William Bartram knew this species was unique, as he never saw the tree elsewhere in any of his extensive travels. He returned to the area in 1776, this time collecting seeds from the Franklin trees and propagating five of them successfully back at his home in Pennsylvania. The last time this species was seen in the wild was at the original wetland floodplain along the Altamaha River between 1790-1803. Now, the only Franklin trees in existence are all descendants of the seeds collected by William Bartram.

A sign in the Brunswick, GA marine extension office/demonstration garden explains the tree’s unique history. Photo credit: Carrie Stevenson, UF IFAS Extension

Their exact cause of extinction is not clear, but there are some solid theories. Land adjacent to the river was cleared for cotton farms, and the Franklin trees were vulnerable to a fungal pathogen that affects cotton. Based on the early records, the very small endemic population was particularly susceptible to habitat destruction and changing climatic conditions.

While no longer growing in the wild, the tree is mostly living in demonstration gardens and Arboretums on the east coast. However, it can be found in the nursery trade and grown in a large swath of the country if cared for properly. I was introduced to this species for the first time at the Brunswick, Georgia marine extension office. In addition to working with fishermen, they also educate residents on native landscaping and ways to prevent stormwater runoff and pollution. Over a span of a few years, they transformed the “front yard” of their office building from a turf lawn with a couple of oaks to a lush landscape full of flowers, shrubs, and pollinator insects. Included is a Franklin tree, with signage explaining its unique history. At about 15-20 feet tall, it has reached mature height. The original site of the Bartrams’ discovery is less than 20 miles from the garden location.

Just a few years ago, this lush garden consisted only of turf grass and a few live oak trees! Photo credit: Carrie Stevenson, UF IFAS Extension
Twig Pruners and Girdlers

Twig Pruners and Girdlers

Not all fall color is a good thing. This statement is especially true when it comes to twig pruners and twig girdlers. These two species of longhorned beetles can certainly disappoint your grand expectations of a beautiful array of fall color. Both species cause the tips of twigs to fall to the ground in late summer, sometimes leaving your trees in an undesirable form.

Twig Pruners

The twig pruner (Elaphidionoides villosus or Anelaphus villosus) is a small longhorned beetle that attacks numerous species of hardwoods. It is usually classified as a secondary pest of declining trees and shrubs. Female twig pruners lay their eggs in late spring at the leaf axils. When the eggs hatch, the grubs bore into twigs and continue to bore as they mature. The larvae then chew concentric rings just underneath the bark. The infested twigs and branches eventually drop to the ground with the larvae inside. The larvae pupate inside the fallen twig throughout the winter.

An adult twig pruner
An adult twig pruner. Photo Credit: University of Georgia

Twig Girdlers

The twig girdler (Oncideres cingulata) is a small longhorned beetle that invades many species of hardwoods. Female twig girdlers lay their eggs in late summer in small twigs (about 3/8 inch diameter) that are covered with a thin layer of bark. The female chews a concentric ring around the outside of the twig, causing the end of the twig to die. The female chews a small notch in the dead twig and lays her eggs. After the eggs hatch, the larvae feed on the dead twigs and develop into adults before chewing their way out. The adults fly away to new host trees.

An adult twig girdler
An adult twig girdler. Photo Credit: Lacy L. Hyche, Auburn University

Management and Control

It’s important to plant the right plant in the right place. Healthy trees and shrubs are the best defense against insect pests. Twig pruners and twig girdlers live in dying or dead twigs and branches. If you have trees that have suffered damage from these pests you will notice an abundance of fallen twig ends around the base of your trees. Rake and remove fallen twigs from around the trees and destroy or dispose them. This will help reduce pruner and girdler numbers in subsequent years.

The Summer Stress is Starting to Show in Trees

The Summer Stress is Starting to Show in Trees

It has been a hard summer climate wise and as we go into fall it is nice to start getting some relief from the heat. As the heat tones down, we are still facing a drought, which is not as severe as areas to our west but is still significant across much of the Panhandle. In our tree cover, the stress from the harsh summer this year is starting to show. You can see it in trees around the area, and it particularly seems to affect certain trees and conditions more than others. Where you are starting to see it most is in our ever-present pines, which make up the majority of our forest and tree cover in our region. If you keep a look out you may notice some pines in the areas with yellowing or brown needles or that are losing their needles. Those are clear signs of a possible bark beetle attack, which is a common issue when pines are stressed or damaged. Trees planted in the last year that are not yet fully established often show stress in a hot dry summer like this year. Even older and well-established trees in areas are showing some signs of stress from the hot dry conditions we have had this summer.  Some trees are less adapted to dryer areas and when planted off site can experience more stress in dry conditions. If you look around across the Panhandle right now you can see clear signs of stress in some trees. It becomes more evident in late summer and early fall as the accumulated stressors of summer push trees into physiological conditions that cause stress responses. The big question is what to do if you notice a landscape tree that is exhibiting signs of stress, particularly drought stress.

Pine damaged by construction equipment. Barking injuries like this can encourage bark beetle attacks. Photo Credit: Ian Stone

For pines the issue is likely to be bark beetles, of which there are several types. All pine bark beetles are native to our area and the degree of damage they do varies by species and conditions. The issue with stressed trees is that most bark beetles attack those trees. When a hot dry summer occurs bark beetle activity increases as the stressed trees become less able to fend off attacks by these beetles. Unfortunately, when bark beetles attack a pine in an area the best answer is prompt removal and disposal of the infected tree material. To protect high value trees in an area where bark beetles are active there are some injection pesticides that can prevent infestation, but once a tree has been infested and begun to show symptoms little can be done to bring it back. When bark beetles attack a stressed pine, most are effectively finishing off a tree that may have died regardless. The key is to prevent them from spreading to other pines in the area or attracting them to a stressed tree in an area. With trees already stressed in our area the big prevention option is not to damage or stress any pines already on the landscape. Most pine bark beetles are attracted to trees by chemicals in pitch and resin given off by wounds or damage. Often the stress from new landscaping projects or construction around pines can cause several to succumb to bark beetles. Your best prevention is to keep equipment well away from the tree and avoid damaging or injuring the tree, especially scraping areas of bark off. Larger and older trees can be vulnerable, as well as overcrowded trees that are too dense or overtopped by others. As the cooler weather approaches bark beetle activity should decrease along with the risk of losing a pine to these pests.

Recently constructed sidewalk. Construction activities extended well into the root zone of the tree, which can cause stress and damage. Photo Credit; Ian Stone

For other trees there are additional precautions that can be taken to lessen the potential that a tree will succumb to drought and other stress. Newly planted trees or those established in the last several years are particularly at risk and should be watered regularly during this dry period. Until rains return, a good method of slowly applying water deeply to the root zone is best. Properly applied mulch can help keep the soil cooler and moist around a newly planted tree. Drip irrigation, soaker hoses, and similar methods are best, and a method that specifically applies water slowly to the tree’s root zone gives the best results. Watering your lawn does not supply sufficient water to landscape trees, especially in drought conditions. Lawn irrigation is designed to apply irrigation needed to the top portion of the soil that is available to the grass. Trees have completely different requirements and need different watering methods and amounts. If you don’t have dedicated irrigation available and you have a tree that needs water, you can use irrigation donuts or bags. These are often a good solution for a tree that needs watering temporarily. Once a tree is well established it usually can withstand even severe drought, but during the establishment phase paying attention to water needs is critical in a summer drought like we have had.

Large established trees are also not immune from the heat and dry conditions that have plagued the Panhandle this summer. Usually when conditions change these trees recover but may abort some branches or exhibit some leaf drop while stressed. Leaf drop is a phenomenon that can occur when deciduous trees are stressed. It is a method of conserving water needs by reducing the leaf demand. Usually, the tree will recover and leaf out again fine next year. A tree may abort some branches or have some branch tips die back to make it through a rough period. Trees that are overcrowded, overtopped, or have other issues are the most at risk from environmental stress. This is why good tree selection along with proper tree care and maintenance is essential. When a hot dry summer like we have had comes along well cared for and maintained trees do best. Trees that prefer more moisture like bald cypress, red maple, sycamore, and some oaks can be planted in dryer sites, but when a severe drought comes along they often don’t have the ability to handle the moisture stress that trees adapted to dryer sites can. This is why site selection is so important, it is when we have extreme conditions that off site plantings typically suffer the worst and those can be larger more established trees.

With the cool weather hopefully we will get a reprieve and some rain soon. Given that fall is one of our dryer periods it may be likely that drought conditions could persist until early winter. Good care and tree maintenance is essential to getting your trees through stressful periods like this summer. For younger trees watering and care is essential while they get established. For older established trees avoid doing any construction or other disturbing activities around them until conditions improve. If you have trees that are exhibiting signs of decline or pest attacks call your local extension office or Florida Forest Service County Forester office. With any luck, colder weather with winter rains will be here soon and trees in our area will recover over the dormant period.

Screen Trees for Privacy and Noise Reduction

Screen Trees for Privacy and Noise Reduction

Sometimes we just need a little privacy. This is especially true if you live on a busy road or just have annoying neighbors. There are a few things to consider when selecting a screen tree: 1) full-grown size; 2) speed of growth; and 3) aesthetics. With these three factors in consideration, let’s review some screen options for different situations.

Pineapple guava
Pineapple Guava (Acca sellowiana) hedge. Photo Credit: Daniel Leonard, University of Florida/IFAS Extension – Calhoun County

Pineapple Guava (Acca sellowiana)

At one time this shrub was hard to find, but it is slowly becoming more available. Pineapple guava is native to South America, but it adapts well to the Florida Panhandle. This plant can reach 10 to 15 feet in height with an equal spread and has a moderate rate of growth, so it’s a great choice when you just need a small screen. Pineapple guava is moderately salt-tolerant and does well in coastal landscapes. As a bonus, the flowers and fruit are edible. It’s hard to find a more aesthetically pleasing large shrub. Pineapple guava is evergreen with leathery green leaves that have grey undersides. This plant can be grown as a large shrub or pruned to be a small tree.

'Emily Bruner' Holly
A large ‘Emily Bruner’ holly at the Santa Rosa County Extension Office. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

‘Emily Bruner’ Holly (Ilex x ‘Emily Bruner’)

‘Emily Bruner’ holly is a cross between the Chinese holly (Ilex cornuta) and the lusterleaf holly (Ilex latifolia). This evergreen shrub has glossy green leaves. It has a pyramidal growth habit and is listed as reaching 15 to 20 feet tall by 5 to 8 feet wide, however the specimen at the Santa Rosa County Extension Office is about twice that size. ‘Emily Bruner’ holly prefers moist, well-drained soil. This holly has dense, prickly leaves so it does well keeping people out of your yard in addition to buffering sound. The flowers have a sweet scent and are a favorite of honey bees.

Dahoon Holly
Dahoon holly foliage and berries. Photo Credit: University of Florida/IFAS

Dahoon Holly (Ilex cassine)

Dahoon holly is native to North America, is tolerant of wet, shady sites (but can also handle full sun), and displays some salt tolerance. This evergreen, small tree is somewhat shrubby. It can grow to be 25 to 30 feet in height with an 8 to 12 foot spread. Dahoon holly has nice light green leaves that are smooth, not prickly like ‘Emily Bruner’ holly. It has a moderate growth rate.

cultivar magnolia
Bracken’s Brown Beauty as an accent tree in a lawn area. Photo Credit: Beth Bolles, University of Florida/IFAS Extension – Escambia County

Southern Magnolia (Magnolia grandiflora)

It’s hard to beat a majestic southern magnolia in the landscape. Why not utilize it as a screen tree? Now, not all southern magnolias are made equal. There are a few cultivars that do well as screens as well as on their own. ‘Bracken’s Brown Beauty’, ‘Claudia Wannamaker’, and ‘D.D. Blanchard’ are three that come to mind and are readily available in the trade. Southern magnolias can reach up to 80 feet tall and 20 to 40 feet wide depending on cultivar and growing conditions. Not only do these three cultivars have beautiful dark green, leathery leaves, their leaves also have brown undersides. These versatile trees can tolerate are variety of soil conditions and they are very wind resistant. And as another bonus, they have beautiful, fragrant flowers.

Eastern Redcedar
Middle-aged Juniperus virginiana ‘Burkii’: Burk Eastern Redcedar. Photo Credit: Ed Gilman, University of Florida/IFAS

Eastern redcedar (Juniperus virginiana)

If your looking for softer texture in your landscape, then you can’t go wrong with a cedar tree. Unbeknownst to its name, eastern redcedar can be found growing all over the United States. This evergreen conifer prefers well-drained sites in full sun. It can grow 30 to 40 feet in height by 10 to 20 feet wide. Eastern redcedars have good salt tolerance. These trees produce beautiful, blue-green foliage. One key to growing this tree successfully is to give it space. Plant trees 12 to 24 feet apart. If using as a screen, you may consider staggering this tree to give it the space it needs.

There are lots of good options when selecting trees for a screen. It’s important you select plants that fit the site. The University of Florida has an excellent plant selection tool found at the Florida Trees for Urban and Suburban Sites webpage.