Garden Talk

with Rebecca Jordi


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Q: My large holly tree fell over after the storm, can it be saved?

Fallen TreeA:  Only trees recently planted or have a trunk diameter smaller than 4 inches should be staked or replanted if they have fallen over during a storm. Large or older trees need to be removed as they were most likely compromised anyway.  If the tree is small enough, prop it back up and do the following:  Keep roots moist but not wet. If the hole is holding water, this might not be the best site for the tree – consider moving it to another area. Trees and shrubs grow best in well-drained soil. Be sure the new hole is wide enough to hold the roots but never plant it too deeply.  The large roots coming off the trunk should be within the first few inches of soil. Remove any circling/girdling roots while they are exposed.  Remember the roots should be going away from the trunk of the tree like the spokes of a wheel.  Prune any jagged and torn roots.  Set the tree upright and fill the hole with native soil – do not be tempted to add amendments to the hole. Water the soil in as this will remove any air pockets.  Good rule is to water with 3 gallons of water per inch of tree diameter. This can be done 3-4 times a week for several weeks until the tree becomes established. In addition, this is NOT the time to add fertilizer.  We want the tree to put out new roots only – not new shoots or flowers. It would be best to stake the tree while it is vulnerable but only leave the stakes on for 6-9 months.  Be sure the cables do not cut or girdle the tree trunk.  Normally, we would not suggest you do any pruning on the tree canopy but remove any cracked or broken limbs at this time.  Remember we do not recommend painting over the wound of the tree – allow the tree to heal over the wounds. Keep grass as far away from the tree as possible – a best management practice all the time.  Mulch several feet away from the trunk – never allow mulch to touch the trunk of any tree. It may take several months to even a year for the tree to overcome the trauma of the storm.  Be patient.  Regarding palms – just remove any totally dead or broken fronds.  Fertilization should not be done again until March of 2017 using only 8-2-12.  Then reapply in June and September.  

 

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Q: What are these growths on my pignut hickory leaves? I think they are insects and they are chewing my leaves

 

Hickory midge gall

Hickory midge gall

A:  I appreciate you bringing in samples of the growths as this helped me identify the problem more easily. Actually, these growths are most likely an insect gall.  Galls are formed when the female insect places an egg in the leaf tissue and then the plant forms a protective coating around the egg.  The egg then goes through its normal growth stage from egg to larvae then pupae exits out of the gall as an adult. Generally, these galls cause few problems for the plant and in some instances, the galls support beneficial insects. I believe the chewing you are seeing on the leaf edges is caused instead by a caterpillar such as the eastern tent caterpillar. Eastern tent caterpillars can be seen in of our area in April – right now!  Just poke holes in the caterpillar webbing and the birds and wasps will take care of the caterpillars for you.


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Q: In your butterfly class you taught the sassafras tree was a good larval food source for some of the swallowtail butterflies. Can you tell me more about the tree?

Sassafras

Sassafras

A:   The Sassafras tree, Sassafras albidum: is a native tree to North America – anywhere from cold hardiness zones 5a – 9a.  It is deciduous, dropping its leaves when the cold weather appears.  It can grow to heights of 60 feet with a 25 – 40 foot spread. Therefore, it would need plenty of space. Historically, the bark and fragrant roots were used for medicinal purposes. According to a publication from Pennsylvania State University, Sassafras was used by Native Americans as a cure-all for a broad range of ailments. An oil extract from the root bark was used to treat diarrhea, nosebleeds, even heart troubles. European settlers and their colonial sponsors were so impressed by the healing powers of sassafras oils the sassafras roots were exported back to Europe in great quantities. In 1602, one ton of these roots sold for 336 pounds Sterling (about $25,000 in modern currency). Leaves were brewed into a medicinal tea and extracted oils were used to make perfume, candy, soap, and root beer. The University of Florida believes we should be planting sassafras for the outstanding display of fall leaf colors.  The multi-lobed leaves have a distinctive aroma when crushed.  Sassafras prefers well-drained, acidic soils and can be grown in most any type of light (full sun to partial shade).  It is highly drought tolerant once it is established.  Its ability to tolerate salt is unknown.  In spring, before the leaves appear, the tree produces yellow, lightly fragrant flowers followed by dark, blue colored fruits which ripen in the fall. These fruit provide an excellent source of food for birds and other wildlife. Although the male plants have showier blossoms, it is the female plants which produce the fruit. Both sexes must be planted to insure good fruit production. Sassafras frequently develops a multiple trunk due to sprouting at the base. Sprouts appear to originate from the root system forming a cluster of showy, grey fissured trunks growing from the soil. This characteristic has helped it invade and colonize old fields and other disturbed sites. Prune early in the life of the tree to form a single trunk suitable for urban landscape planting, or grow with multiple trunks for a dramatic specimen. Single-trunked trees are best-suited for street tree planting and other urban and suburban areas, and they usually maintain this good form without pruning.


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Q: What can you tell me about the Florida sand pine?

Pinus clausa leaves

Pinus clausa leaves

A:  The sand pine, Pinus clausa, is a native pine tree and a relative of the common Florida slash pine.  The sand pine has shorter needles, is shorter in height than its cousin and does not live as long as the slash pine.  Because it does not produce tall trunks, it is of little importance to the lumber industry except for occasional usage for pulp. However, it is very valuable to wildlife throughout the state.  According to the Department of Agriculture, sand pines play an important role in the lives of more than 20 threatened or endangered species as these animals live in or utilize sand pine forests. In addition, sand pines provide cover and nesting sites for many songbirds, woodpeckers and squirrels. Small mammals and rodents feed on the seeds which attracts large birds of prey. Sand pines tolerate most any kind of soil conditions except wet sites. Although, as its name implies, sand pines are found most often in coastal, sandy soils.  It can grow in most any type of light condition and is highly salt (aerosol) and drought tolerant.  Sand pines grow slowly with normal heights of 20 – 40 feet.  The needles of the sand pine are 2 – 3.5 inches long which is short when compared with the slash pine’s needle length of 7 – 12 inches.  Sand pines are not known for having a straight trunk and often will take on a “bonsai” look by growing more limbs on one side of the tree. This does not mean there is anything wrong with the tree.  It has few diseases problems which should make it a nice addition to landscapes along the coast as long as it is not over watered. The trees can be susceptible to bark beetles and sand pine sawflies.  There are two varieties of sand pine, the Ocala, found in most areas of Florida, while the Choctawhatchee sand pine is found further north in the panhandle area of Florida. The only difference between the two trees is the cones.  Ocala cones display a waxy covering and stay closed whereas the Choctawhatchee cones open up to expose the seeds.  The Choctawhatchee sand pines are often grown as Christmas trees. We just added the sand pine to our large demonstration garden at the James S. Page Governmental complex.  We will need to give it a year or so to see if it can adapt to a more urban environment.   https://edis.ifas.ufl.edu/pdffiles/ST/ST45800.pdf


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Q: What can you tell me about the Japanese blueberry shrub and can I grow it here?

 

Japanese Blueberry

Japanese Blueberry

A:   Japanese blueberry, Elaeocarpus decipens, can be grown in our cold hardiness zone. This evergreen tree grows about 30 to 40 feet tall and equally as wide. Japanese blueberry prefers well drained soil and full sun. Some interior foliage turns bright red and drops in spring and periodically throughout the year. This is normal and is not cause for concern. Japanese blueberry has small, inconspicuous fragrant flowers.  It has a propensity to become chlorotic on high pH soils so this might limit using it in commercial or home sites where soil is often alkaline. It is too difficult to lower the pH for any substantial amount of time to keep the plant lush and green in an alkaline environment. The high production of fruit may cause it to be messy on walkways. However, berry production should not be a problem if using it as a hedge in a home landscape.  Just keep its shrub away from driveways and sidewalks.  Piercing sucking insects may be a problem, but early scouting of insect feeding can be controlled with either insecticidal soap or ultrafine horticulture oil. Formation of sooty mold is your best indication the pest populations have become too high.


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Q: Would Tea Olive be a good hedge choice here?

Tea Olive

Tea Olive

A: Tea Olive, Osmanthus fragrans, is a small evergreen tree or shrub which can grow up to 25 feet tall but typically is about 15 feet tall with10 feet spread.  The lustrous, medium‐green leaves have paler undersides and are joined from October through March by a multitude of small, but extremely fragrant, white blossoms. They perfume a large area of the landscape and can be showy in some years. I believe they would make an excellent hedge as long as you kept them tall.   It tolerates full sun to part shade but does poorly in wet sites and where soil does not drain well. It is not salt tolerant and although can fit into a landscape well with typical lawn irrigation, the one at my office receives no additional water outside rainfall and does beautifully.  No pests or diseases are of major concern. Scales and nematodes may present a problem, and mushroom root rot is troublesome when the soil is kept too wet.  With its upright oval to columnar growth habit in youth, Sweet Osmanthus is ideal for use as an unclipped hedge or trained as a small tree, and should be placed where its fragrance can be enjoyed. Since the flowers are not particularly showy, people will wonder from where the delightful fragrance originates. This is a subtle plant which should be used more often in Southern landscapes. Plants thin somewhat in the partial shade, but form a dense crown in a sunny location. Planted on 4 to 6 foot centers, Sweet Osmanthus can form a wall of fragrance during the fall, winter and spring and should be planted more often. They will not grow as fast as Leyland Cypress, but think of this Osmanthus as a substitute for use in a sunny spot. Plants can be clipped to form a denser canopy, but flowers form on old stems.


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Q: What is this tree? The leaves are changing color now. I have only one of these on my property.

Turkey Oak

Turkey Oak

A:   Thanks for bringing in a sample for me.  Right now this tree, Turkey oak, Quercus laevis, is showing us rusty, brown colors.  Quercus is the Latin name for “oak,” and laevis comes from the Latin word meaning “smooth, slippery, or polished,” which refers to the tree’s nearly hairless leaves. Turkey oak, or turkey-foot oak, received its common name from the shape of its leaves, which resemble a turkey’s foot. These trees can be found from Virginia, south to central Florida, and west to southeastern Louisiana. Turkey oak is also known as scrub oak—referring to the habitat where the species is commonly located.  Turkey oaks provide food for wildlife such as the black bear, white-tailed deer, and wild turkey.  This tree has a high resistance to wind and is also drought tolerant. Turkey oak trees grow to about 40 feet but can reach heights of 70 feet. They are often found growing in high bluff areas so here in Nassau County, Florida we can find them in Hilliard and Yulee. Turkey oaks have been known to produce large amounts of pollen in the spring which can cause problems for people with allergies. The tree’s wood has been used for lumber and general construction, but is commonly used for fuel wood, barbecuing, and farm construction. http://edis.ifas.ufl.edu/fr312