Tag Archive: Trees

Arborists Help Maintain Healthy Trees

Trees are a valuable resource. They add beauty to our community, serve as food and shelter for animals, filter the air, and cool urban environments. Trees can also be a liability when poorly maintained, damaged, or diseased. There are often times when an arborist is needed to help determine the best course of action for the tree.

There are many individuals who are involved in the tree care and removal business. Not all of these people are certified in the care of trees. Arborists are people who receiving training in the planting, care, and maintenance of trees.

Professional arborists have specialized training to create safe, structurally sound trees, even when damaged by storms. Photo by Beth Bolles, UF IFAS Extension Escambia County

Certified arborists go through a voluntary certification process with the International Society of Arboriculture which means that they have at least three years experience and have passed a comprehensive examination developed by tree experts. A certified arborist maintains certification by attending regular training courses.

An arborist may also be a member of another organization which helps professionals stay up-to-date on tree care techniques and information. These include the National Arborist Association and the American Society of Consulting Arborists.

Hiring an arborist to work on your trees is important for several reasons. An arborist can evaluate the tree and determine the steps necessary to create a healthy specimen. In regards to pruning, the professional will determine what type of pruning is necessary and remove branches properly.

Professionals will also perform tree care practices that are recommended by University research.   A few practices that the arborist would not perform include topping trees, using climbing spikes on trees which are not being removed, and making flush cuts against the trunk.

Flush cuts are damaging to trees and can create a future hazard in your landscape. Photo by Beth Bolles, UF IFAS Extension Escambia County

 

Finally arborists have the skills and equipment to safely and efficiently prune or remove trees.  This includes personal and property damage insurance and workers compensation insurance.

Next time you need tree work or advice, hire a professional for the job. It will definitely be worth the investment.

PG

Author: Beth Bolles – bbolles@ufl.edu

Horticulture Agent, Escambia County

Beth Bolles

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2017/09/09/arborists-help-maintain-healthy-trees/

Struggling to Grow Fruit Trees? Try These Lesser Known Florida-Friendly Edible Options!

Northwest Floridians are lucky.  We get to bask in the warm sunshine at least eight months of the year, consider it cold weather when we have to break out the fleece pullover and none of us live more than a few hours’ drive to the whitest sand you ever saw.  However, those conditions have consequences.  That warm sun and plentiful rain yields heat and humidity, a perfect breeding ground for all manner of pests and diseases, not to mention seriously cutting down on necessary chill hours required by many species.  We’ll never be able to grow peaches like they do in Georgia.  No one is in any danger of mistaking a Florida apple for one from Michigan.  Pomegranates, olives, and nectarines like California?  Forget about it.  All of those species will mostly survive and grow but in most cases, the inputs of labor and protective chemicals greatly outweigh the output of fruit.  For most of us it is just not worth the time and effort to turn a crop!

We have a couple of adapted, well-known stalwarts to turn to though.  Any gardener worth his salt has a few productive rabbiteye blueberries (Vaccinium ashei), a pear (Pyrus communis), an old reliable fig tree (Ficus carica), and a citrus or two of some kind (though with the devastating disease known as Citrus Greening looming on the horizon, backyard citrus may decline in popularity in the near future).  However, hobby fruit growers aren’t often content to stick to those standards though.  We tend to be an adventurous, progressive lot, always looking for new species to grow and constantly pushing climatic and adaptation limits of species, with varying success. For the Panhandle backyard fruit orchardist looking for a little variety but demanding a high probability of success, there are three unusual Florida Friendly trees requiring little winter chill that fit the bill perfectly:  Pawpaw (Asimina triloba), Japanese Persimmon (Diospyros kaki), and Loquat (Eriobtrya japonica).

Pawpaw fruit

The pawpaw (yes it’s pronounced exactly like you think it is) is an altogether unusual tree.  For starters, it is one of the most adaptable plants in cultivation, growing native from New York all the way down to the Sunshine State.  It would be a beautiful tree if it never produced a single fruit; the large leaves droop naturally, lending a decidedly tropical feel to the garden and the understated purple-brown flowers are some of the more attractive of our native spring blooming trees.  But, to be sure, the fruit are the real attraction here.  Technically berries, the bluish-green, three to five inch long, oval-shaped fruit ripen in the late summer (August-October) and have an extremely unique taste often likened to banana or custard.  Pawpaws occur naturally in moist, well-drained soils and thrive in both shade and sun; site accordingly and this unusual little native fruit tree should perform admirably for you!

While more common than Pawpaw, Japanese Persimmon still has not reached the cosmopolitan status of pear or fig or the like for reasons unclear to me!  Native to eastern Asia, Japanese Persimmon is right at home in the Panhandle where it rewards gardeners each fall with outstanding reddish/orange foliage and a reliable crop of beautiful, baseball-sized, orange fruit possessing a crisp, sweet taste that can be eaten fresh or used in cooking.  I especially like the fruit when it is made into a cakey “bread” similar to banana bread.  It is a remarkably forgiving tree, growing and fruiting reliably with little help from the orchardist.  Japanese Persimmon is generally sold as one of the selected cultivars, ‘Fuyu’ being the most common and probably the best.  The species prefers full sun and moist, well-drained soil but does just fine without irrigation once it reaches establishment.  A bonus, you only need to plant one as Japanese Persimmon does not require a pollinator!  (Note:  Persimmons can be astringent or non-astringent.  If you plant an astringent cultivar, be sure to let the fruit ripen completely before eating as they are unpalatable until that point.  Most are probably better off going with a non-astringent cultivar such as ‘Fuyu’.)

Persimmon fruit

A lesser-known gem of the coastal south, Loquat is hard to beat.  It’s a great addition to the landscape, the cinnamon colored bark, foot-long “cabbagey” textured leaves and early spring flowers outdo many purely ornamental species.  The yellowish-orange fruit that follow are outstanding picked and eaten fresh off the tree.  Flavor is reminiscent of citrus with a sweet taste and a soft texture.  Loquat flourishes in full sun and once established needs little to no supplemental fertilization or irrigation.  As with Japanese Persimmon, Loquat is self-fertile and does not need a pollinator so just one tree will do (trust me, one healthy loquat will make enough fruit to feed a small army)!

Loquat fruit

If you are indeed a backyard orcharding enthusiast and want to expand your horizons to include more than the same old standard species that everyone else grows or maybe you’re just frustrated with trying to grow popular but ill-adapted species like peach and apple, you could do a lot worse than including one or all of Pawpaw, Japanese Persimmon, and Loquat into your garden!  For more information on fruit trees and any other horticultural questions you may have, contact your local UF/IFAS Extension office.  Happy gardening!

 

PG

Author: Daniel J. Leonard – d.leonard@ufl.edu

Horticulture Agent, Walton County

Daniel J. Leonard

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2017/08/25/struggling-to-grow-fruit-trees-try-these-lesser-known-florida-friendly-edible-options/

Avoid Pitfalls in the Care of Newly Planted Trees and Shrubs

This time of year, people flock to nurseries and garden centers to purchase trees or shrubs that will enhance their landscapes. However, there are certain management measures to keep in mind to ensure plant establishment. Depending on the season, newly planted trees and shrubs need varying degrees of watering, mulching, pruning and trunk staking.

Figure 1: Tree Planting.

Credit: UF/IFAS Communications.

The primary focus in care of your newly planted tree or shrub is root development. It takes several months for roots to establish, and newly planted trees and shrubs do not have a very strong root system. Start by digging the hole in a popcorn bowl shape. Once planted, backfill around the root system, but be careful not to compact the soil. Compaction will hinder root growth. Be sure to keep the topmost area of the root ball exposed, about two inches. A layer of mulch will be applied here.

Frequent watering is much needed, especially if you are planting in the warmer months. Water thoroughly, so that water percolates below the root system. Shallow watering promotes surface root growth, which will make the plant more susceptible to stress during a drought. Concentrate some of the water in a diameter pattern of a few feet from the trunk. This will cause the root system to grow towards the water, and thus better establish the root system and anchor the tree.

Mulch is important in the conservation of soil moisture. Pine needles, bark and wood chips make a great mulch for ornamental shrubs. A two to three inch layer of mulch will usually suffice. It’s important to keep the mulch at least a few inches from the trunk. Mulching too close to the tree trunk can cause trunk rot.

You should always prune the bare roots of trees and shrubs during planting. Exposed roots in containers can be damaged in shipping. Removing some of the roots will also help trigger growth. In addition, pruning some of the top foliage can reduce the amount of water needed for the plant to establish. 

Newly planted trees and shrubs often have a difficult time establishing if the root system cannot be held in place. Strong winds and rain can cause the plant to tip over. Avoid this by staking the plant for temporary support. A good rule of thumb for plant staking is if the trunk diameter measures three inches or less. Tie the stake to the plant at every six inches from the top. However, only tie the trunk at one spot. Don’t tie too tightly, so that the tree has no flexibility. This will stunt the growth of the plant.

Larger trees and shrubs will need diameter staking with wire support. Four stakes evenly spaced at six feet around the trunk is a good arrangement. Each stake can be attached to the tree just above the mid-point using cable or wire. Be sure to cover the wire around the trunk with a short piece of hose to prevent any scarring of the bark. The wire should be snug, but not tight. After one year, the staking can be removed.

Following these tips will help ensure your tree or shrub becomes well established in your landscape. For more information please contact your local county extension office.

Supporting information for this article can be found in the UF/IFAS EDIS publication: “Specification for Planting Trees and Shrubs in the Southeastern U.S.” by Edward F. Gilman: http://edis.ifas.ufl.edu/pdffiles/EP/EP11200.pdf

Supporting information also provided by UF/IFAS Extension Forestry Specialist Dr. Patrick Minogue, of the North Florida Research Education Center in Quincy, Florida.

UF/IFAS Extension is an Equal Opportunity Institution.

 

PG

Author: Ray Bodrey – rbodrey@ufl.edu

Gulf County Extension Director, Agent II Agriculture & Natural Resource, Horticulture, Sea Grant

Ray Bodrey

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2017/05/25/avoid-pitfalls-in-the-care-of-newly-planted-trees-and-shrubs/

Want Fall Color? Plant These Trees !

Want Fall Color? Plant These Trees !

 

Ginkgo

Ginkgo

Florida has so much to offer!  It is home to the world’s most beautiful beaches. It has one of the largest agricultural economies nationwide.  

But among all these things, Florida is lacking in one area that is very noticeable come fall:  all the beautiful red, yellow, and orange leaf colors that paint the autumn landscape just a few hours to the north!

As frustrating as the lack of fall color in Florida’s native forests may be, this situation is easily amended in yards throughout the state by planting some autumn color standouts!  Here are three of the very best for Northwest Florida:

 

  • Ginkgo (Ginkgo biloba)

This holdover from the Jurassic Period (Literally! Fossil records indicate Ginkgo has existed virtually unchanged for well over 100 million years!) has much to offer as an ornamental tree, including spectacular golden-yellow fan-shaped leaves in fall!  Somewhat ungainly in youth, a mature Ginkgo is truly a sight to behold, an 80-100’ tall, imposing specimen.   Ginkgos are very tolerant of all soil conditions except waterlogged, have few insect and disease pests, and are remarkably drought-tolerant once established. Be sure to select a male cultivar however, as female trees produce extremely odiferous seeds that remarkably resemble rancid butter!

  • Chinese Pistache (Pistacia chinensis)
Chinese Pistache

Chinese Pistache

A little-known, much underused tree in the Deep South, Chinese Pistache will light your landscape aflame with brilliant, orange-red fall foliage.  One of the last trees to turn color in the fall, Chinese Pistache can help extend the show deep into November!  It is a small to medium sized tree that will not overwhelm any but the smallest landscapes.  As with Ginkgo, the habit of the tree in youth is awkward at best and the tree’s full potential is not realized until maturity when it becomes a dense, oval-round specimen.  Chinese Pistache is close to bulletproof, tolerant of drought and poor soil conditions.

  • Black Gum (Nyssa sylvatica)

One of Northwest Florida’s best native trees for fall color is Black Gum.  Black Gum is a standout tree, pretty in all seasons, possessing dark, almost-black bark, a tall pyramidal habit and vivid fall foliage in the deepest shades of red and purple.  As a bonus, Black Gum usually begins its color change very early, occasionally in September.  The addition of this tree to a lawn dominated landscape can deliver at least an extra month of color!  Black Gum prefers moist, deep soils but is found in dry flatwoods and swamps alike, betraying its adaptability.

Young Black Gum Tree

Young Black Gum Tree

Including the above trees in new or existing landscapes is an easy, smart way to extend the fall color show from September through November and make home gardeners long a little less for the colorful northern autumns!  Happy Gardening!

 

 

PG

Author: dleonard – d.leonard@ufl.edu

dleonard

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2016/11/18/want-fall-color-plant-these-trees/

Purple Triangles in the Trees

Purple Triangles in the Trees

From time to time I am reminded of how little I know.  Honestly, I am reminded on a daily basis. A few weeks ago someone asked me about the purple things hanging from the trees. Luckily, the person gave me some good southern directions on where I could find one of these things hanging around in Marianna. So I drove out to the site to get a better look. What I saw hanging in the tree was a three-sided, purple triangle about two feet tall and a foot wide.  It looked to me like someone got a box kite stuck in a tree. Upon further research, it was determined this box kite like thing was a monitoring trap for the emerald ash borer (EAB).

A woman hanging an emerald ash borer trap in a tree. Photo Credit: Texas A&M University

A woman hanging an emerald ash borer trap in a tree. Photo Credit: Texas A&M University

The emerald ash borer (EAB) is a destructive, exotic wood-boring beetle native to Asia. It was first discovered in North America in July 2002 and has made a home in Michigan, Ohio and Ontario, Canada. Millions of ash trees have been killed by the EAB in Michigan and invested ash tree nursery stock in other states indicates the potential for increased spread of the pest. EAB has made its way to the south and has been found in Louisiana and Arkansas.

Monitoring traps are not the only means of EAB detection. A proactive approach utilizing observant citizens can help keep an eye out for potential populations. You can use these tips to monitor your community for emerald ash borers:

Ash Tree Identification – Ash trees are identified by their (1) opposite branching pattern, (2) compound leaves with 5-9 leaflets, and (3) diamond shaped bark ridges on mature trees.

A compound leaf of an ash tree. Photo Credit: FDACS

A compound leaf of an ash tree. Photo Credit: FDACS

Woodpecker Damage – Of course, not all woodpecker damage on ash trees is associated with EAB infestation, but woodpecker damage in the upper part of the tree can indicate their presence.  The woodpecker damage is usually accompanied by vertical cracks in the bark.

Canopy Thinning – As the attack progresses, bark cracking continues and the canopy in the upper half of the tree begins to thin.

Michigan ash tree showing decline due to Emerald ash borer. Photo Credit: USDA

Michigan ash tree showing decline due to Emerald ash borer. Photo Credit: USDA

Tunnels and Holes – The emerald ash borer makes distinctive S-shaped tunnels that differ from damage from other borers.

EAB Damage (left) VS Other Borer Damage. Photo Credit: Texas A&M University

EAB Damage (left) VS Other Borer Damage (right). Photo Credit: Texas A&M University

This beetle hitchhikes on firewood and infests new areas at an alarming rate.  Although the EAB has not yet been detected in Florida, transporting firewood from other states puts Florida ash trees at risk. Your help is needed to detect possible infestations so they can be quickly eradicated. The information available at the following links will help you identify the EAB, EAB host trees, and infestation symptoms.

 

PG

Author: Matt Lollar – mlollar@ufl.edu

Matt Lollar is the Jackson County Horticulture Agent. He has 5 years of experience with University of Florida/IFAS Extension and he began his career in Sanford, FL as the Seminole County Horticulture Agent. Matt is originally from Belle Fontaine, AL. He earned his MS and BS degrees in Horticulture Production from Auburn University.

Matt Lollar

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2016/05/24/purple-triangles-in-the-trees/

Cold Weather is a Good Thing for Fruit Trees

Cold Weather is a Good Thing for Fruit Trees

We may be suffering from the recent low temperatures, but temperate fruit trees such as peaches and apples require a period of cold weather in order to become cold hardy and produce a good crop.

What is Cold Hardiness?

Cold hardiness is the ability of a plant to survive low temperatures.  However, every cold event is fairly unique with variables such as when the low temperatures occur (early vs. late winter), how quickly the temperature drops, the temperatures in the days leading up to the event, and the length of time the low temperatures are sustained.

Cold Acclimation

Cold acclimation is the development of freezing tolerance in plants.  Three fall environmental factors contribute to cold acclimation in fruit trees.  Plant will develop 10 to 15 degrees of cold tolerance when the leaves sense shorter day lengths.  Metabolic activity is increased when days are short and temperatures are between 60°F days and 40°F nights.  The second factor occurs when lows reach the 20s, which can make trees up to 10 degrees hardier.  The final factor occurs when temperatures dip to near zero, which fortunately for us does not occur very often.

Trees remain hardy during the winter as long as temperatures remain fairly stable.  However, de-acclimation occurs in reaction to warm temperatures.  This explains the winter flowering which occurred this past December.  A cold snap may not injure trees unless it immediately follows a period of mild temperatures.

Florida Average Chill Hours Map

Florida Average Chill Hours Map – UF/IFAS Extension

Chilling Requirement

The cold weather and gradual cold acclimation are necessary to a tree’s accumulation of chill hours which is necessary for steady fruit yields.  Chill hours are the accumulation of hours when temperatures are between 32°F and 45°F.  The yearly average chill hour accumulation in Northwest Florida is between 660 and 700 hours.  The apple varieties recommended for our area (‘Anna’, ‘Dorsett Golden’, and ‘TropicSweet’) have a chilling requirement of 250 to 300 hours.  Some of the peach varieties recommended for our area (‘Flordacreast’, ‘Flordaking’, and ‘Gulfsnow’) have a chilling requirement of 350 to 400 hours.  Please note the risk of planting these varieties because their chilling requirements are lower than our average chill hour accumulation.  The varieties listed are for example, but other available varieties are suitable for our area.

Whether you like winter weather or not, just remember the satisfaction of eating fresh fruit in the summer.  To track this year’s chill hours from the warmth of your home, please visit the AgroClimate tool at http://agroclimate.org/tools/Chill-Hours-Calculator/.

 

PG

Author: Matt Lollar – mlollar@ufl.edu

Matt Lollar is the Jackson County Horticulture Agent. He has 5 years of experience with University of Florida/IFAS Extension and he began his career in Sanford, FL as the Seminole County Horticulture Agent. Matt is originally from Belle Fontaine, AL. He earned his MS and BS degrees in Horticulture Production from Auburn University.

Matt Lollar

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2016/01/27/cold-weather-is-a-good-thing-for-fruit-trees/

Time to Plant Pecan Trees

Time to Plant Pecan Trees

Pecan trees are well adapted to our area, making beautiful large shade trees. And, if the correct varieties are planted, they can provide pecans.

Only those pecan varieties that show some real resistance to disease problems are recommended for planting here in the humid south. Select grafted trees of Desirable, Curtis, Elliott, Moreland or Stuart varieties.

Pecan leaves and fruit. Photo credit: Brad Haire, University of Georgia, Bugwood.org

Pecan leaves and fruit. Photo credit: Brad Haire, University of Georgia, Bugwood.org

Obtain and plant your pecan trees during the winter – December through February. Purchase trees that are three to six feet tall. Larger trees are more difficult to transplant.

Give pecan trees plenty of room to grow. The distance between trees should be approximately sixty feet because mature trees are quite large. Commercial producers sometimes use a closer spacing, primarily because they are using varieties that will bear at an earlier age. But most of those varieties do not have good disease resistance and still require pesticide spray at times. Homeowners will not have the needed equipment to spray a large pecan tree and the drift from such sprays would not be desirable around your home, so commercial varieties aren’t recommended for home plantings.

One of the keys to survival of a pecan tree is not allowing the root system to dry out before, during or after transplanting. Regular watering will be required for a period of at least six months or until the young tree is well established. The planting hole should be 18 to 24 inches wide and only as deep as the root system. Spread the roots so they are not matted together. The planting depth is critical. Place at such a depth that the uppermost root is at or near the soil surface. Excessively deep planting can result in eventual death of the tree.

When planting your tree, there is no need or advantage to using peat moss, compost, manure or other organic matter in the planting hole. Plant the tree in the native soil without amendments.

Do not fertilize when the tree is planted. Wait until May of the first year after planning to apply fertilizer.

Remember that pecan trees are large at maturity, with branches spreading 30 feet or so from the trunk. Also, because of the brittle limbs and failing nuts, it’s best not to plant these trees too near the home, driveway or sidewalk.

 

PG

Author: Larry Williams – llw5479@ufl.edu

Larry Williams is the County Extension Director and Residential Horticulture Agent for the UF/IFAS Extension Office in Okaloosa County.

Larry Williams

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2016/01/14/time-to-plant-pecan-trees/

Is That Cotton Growing in My Trees?

Is That Cotton Growing in My Trees?

With the cotton harvest coming to an end, it’s not unusual to see cotton littered on the sides of the road.  You may also think you see it hanging in the trees, but you will be pleasantly surprised to find a hidden gem.  Woodbine (Clematis virginiana) and coastal virgin’s bower (Clematis catesbyana) are two native species of clematis that can be found wrapped around trees in the Panhandle.  They have finished flowering for the year and you will notice their showy seed lint hanging in the trees.

Clematis growing in an oak tree. Photo Credit: Matt Lollar, UF/IFAS

Clematis growing in an oak tree. Photo Credit: Matt Lollar, UF/IFAS

Clematis leaves are compound, consisting of 3 to 5 leaflets, dark green and glossy with toothed edges.  The vines are typically 1/2 inch in diameter and can grow to 20 feet.  The flowers are much smaller than those of cultivated varieties found at garden centers. Flowers are white with prominent stamens.  Clematis catesbyana and Clematis virginiana have similar flowers, but the flowers of C. virginiana are fragrant.

Clematis species grow well in partial shade to full shade.  Native plants are often found entwined in the forest understory near streams or ponds where soil conditions are moist.  Garden varieties grow well with their roots in moist, shaded soil and their leaves and flowers in the sun.  They are often seen growing on a trellis or on a fence.

Clematis 'General Sikorski'. Photo Credit: Karen Russ, Clemson University

Clematis ‘General Sikorski’. Photo Credit: Karen Russ, Clemson University

It is important to note that some species of clematis are invasive.  Sweet autumn clematis or Japanese clematis (Clematis terniflora) is a vigorous invasive species that was once popular in southern gardens.  This species has similar characteristics to C. catesbyana and C. virginiana, but its leaflets have smooth edges.  You should develop a control strategy if Japanese clematis is found in your garden.  For control options, please visit EDIS – Japanese Clematis.

 

PG

Author: Matt Lollar – mlollar@ufl.edu

Matt Lollar is the Jackson County Horticulture Agent. He has 5 years of experience with University of Florida/IFAS Extension and he began his career in Sanford, FL as the Seminole County Horticulture Agent. Matt is originally from Belle Fontaine, AL. He earned his MS and BS degrees in Horticulture Production from Auburn University.

Matt Lollar

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2015/12/16/is-that-cotton-growing-in-my-trees/

Time to Plant Trees & Shrubs

The cooler weather in the wintertime makes it a great time to plant trees and shrubs. That is why Arbor Day in Florida is the third Friday in January. In 2016, that event is January 15.

Baldcypress growing at the edge of a pond. Photo:  Julie McConnell, UF/IFAS

Baldcypress growing at the edge of a pond. Photo: Julie McConnell, UF/IFAS

Start your planning now with doing a site assessment on your landscape, then choosing the right trees and shrubs for your particular environmental conditions.

Here are some great sites that offer online tools for finding just the right species:

Florida Tree Selector

The Florida-friendly Guide to Plant Selection & Landscape Design

Florida Native Plant Society Locator

And if you want to find out just how much your established trees are worth, use this National Tree Benefit Calculator!

 

For more information:

Planting Trees in the Landscape

Arbor Day Foundation: Florida

PG

Author: Mary Derrick – mderrick@ufl.edu

Residential Horticulture Extension Agent for Santa Rosa County

Mary Derrick

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2015/12/05/time-to-plant-trees-shrubs/

Tung Trees – Historic Crop; Toxic Legacy

The bright blossoms of the tung oil tree come from the center of new growth.  Photo by Jed Dillard

The bright blossoms of the tung oil tree come from the center of new growth. Photo by Jed Dillard

The highway from Monticello to Tallahassee (US 90) is famous for its summer blooming crape myrtle trees donated by nurseryman Fred Mahan. This month, there’s another historic tree flowering along that highway, as well as in other parts of Jefferson county and North Florida. It’s the tung tree, imported from China to build a thriving agricultural industry from Gainesville to the Mississippi Gulf Coast.

Pretty as it is, all parts of the tung tree (Aleurites fordii) are toxic to humans and livestock, the nuts especially so. Due to the high content of durable oil in the nuts, they can last on the ground until they sprout, thus generating an ongoing population from the plantings that totaled over 12,000 acres in the county at the industry’s peak. If the nuts sprout in an over grazed pasture or a fence row, they’re subject to being grazed. Worst case scenario would be an animal ingesting a nut, but they’re two to three inches in diameter and unlikely to be swallowed. In addition to its toxicity, the tung tree is now designated a Category II species on the Florida Exotic Pest Plant Council Invasive Plant list.

Identification
This time of year, the blooms are most noticeable. They’re creamy white with a distinctively patterned rose colored center (as seen in the image above). They occur on the terminal buds of last year’s shoots. The alternate leaves may be up to six inches wide and are dark green. They’re usually heart shaped, but may be lobed. The fruits are usually round and green to purple at maturity, containing 4 to 5 seeds, the source of the highly sought oil. The fool proof identification is the presence of two small red glands where the leaf joins the petiole (as seen in the image below).

Whether the leaves are heart shaped or lobed, the two small red glands are definitive identification.  Photo by Jed Dillard

Whether the leaves are heart shaped or lobed, the two small red glands at the base of the leaf are a definitive identification. Photo by Jed Dillard

Control
The tree spreads from seed as well as by formation of suckers. As always, early detection and removal is the first line of defense against these trees. Removing the trees before they begin seed production will prevent dispersing the nuts that might occur in the disposal of a mature tree. When removing trees, take precautions to avoid skin contact and be sure to pick up and destroy all seeds that may have already fallen from the tree.

As with most unwanted small trees, the cut stump and basal bark methods of control are the preferred methods of herbicide application. Triclopyr is the preferred active ingredient of choice, and further information on these methods is available in the following UF/IFAS Publication:  Herbicide Application Techniques for Woody Plant Control

For more information on identification and control of the tung tree contact your local Extension agent or go to the UF/IFAS Center for Aquatic and Invasive Plants – Tung oil tree. If you’d like to learn more about the history of the tung industry in Florida, check out “The History of Tung Oil” by Karen Brown and William Keeler.  Just remember to take out the trees first!

 

PG

Author: Jed Dillard – dillardjed@ufl.edu

Jefferson County Livestock and Natural Resources Agent with a commercial cow/calf background. My degree is in animal breeding, but I do more work wth forage systems. Long time clover/legume booster for both livestock and wildlife

Jed Dillard

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2015/03/28/tung-trees-historic-crop-toxic-legacy/

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