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.

American beautyberry

American beautyberry

When beautyberries start producing their eye-catching, bright purple fruit in late summer, we start to get lots of questions. People want to know what it is, where can they find it, and can they eat it? While the berries look good enough to eat, it’s best to leave them to the birds and deer. They are not toxic and were used by Native Americans for a root tea to treat fevers, stomach aches, malaria, and more, but the taste has been described as bitter and mealy. Thanks to a generous volunteer, I am lucky enough to have tried beautyberry jelly. A little (or a lot) of sugar can make most anything taste good—and the finished product is a beautiful, translucent shade of fuchsia.

Homemade beautyberry jelly is a real treat for breakfast! Photo credit: Carrie Stevenson, UF IFAS Extension

Even more interesting to me was the revelation that researchers have been able to extract compounds from beautyberry that successfully repel pest insects such as ticks and mosquitoes. The study began about 15 years ago, after a Mississippi botanist with the USDA Agricultural Research Service mentioned to a colleague that his grandfather taught him to rub the crushed leaves of beautyberry on his skin. The technique had been used as a home remedy to prevent mosquito bites for people (and horses) for generations. As a follow up experiment, another group of researchers found these same compounds—callicarpenal and intermedeol—successfully repelled black-legged ticks (which transmit Lyme disease) as effectively as DEET. In the last few years, researchers out of Mississippi have worked towards creating natural insect repellents from the compound that are less harsh on human skin that many commercially available brands.

The striking purple berries of the beautyberry shrub attract the attention of people and wildlife, alike. Photo credit: Carrie Stevenson, UF IFAS Extension

Aside from its many practical uses, Callicarpa americana is a beautiful native shrub. It has wide green leaves and the brilliant purple berries grow in clusters along its stem. They stay on through late fall and winter in some places, making a beautiful contrast to fall foliage. Beautyberry shrubs can be found in a wide variety of habitats, including sandy and wet soils, full sun, and part shade. Their adaptability makes them a great plant for tight conditions like roadsides or yard edges, but also for nearly any home landscape. The plants can grow to a height of 4-8 feet and spread 3-6 feet wide. The long-lasting berries make them a great wildlife food source later in the cool season than many berry-producing species.

Bot Rot: Sweet Viburnum’s Achilles Heel

Bot Rot: Sweet Viburnum’s Achilles Heel

Sweet Viburnum (Viburnum odoratissimum) is thought of as being an ironclad landscape shrub, generally a rapid, healthy grower free of insects and disease.  However, this spring, many Sweet Viburnum specimens across the Panhandle have experienced varying degrees of dieback, from individual shoots to entire sections of shrubs, caused by the fungal pathogen Botryosphaeria – commonly known as Bot Rot.

Typical symptom of Bot Rot on Sweet Viburnum. Photo courtesy of Daniel Leonard.

Bot Rot almost always appears after some kind of major stress event that impacts susceptible plants – drought, pruning wounds, nutritional deficiencies, or another environmental stress.  We haven’t been afflicted lately with any serious drought conditions and the disease occurrences are too widespread to have been a result of isolated pruning or poor plant nutrition.  However, the Panhandle did experience a major environmental event around Christmas 2022 that was plenty stressful for landscape plants, a weeklong Arctic blast of extreme cold.  This abrupt hard freeze event in an otherwise mild winter is my best guess for what brought about the increased incidence of Botryosphaeria we have experienced this spring.

The Botryosphaeria fungus enters plants via wounds – in this case one probably caused by cold – and begins destroying the plant’s vascular system in the area.  As the pathogen progresses, it eventually causes sunken cankers to appear, girdles the affected branch, and cuts off “circulation” in that stem.  The first symptom of Bot Rot that gardeners notice is shoots rapidly wilting and exhibiting a blighted appearance, with brown, dead leaves holding onto affected limbs.  Unfortunately, dieback isn’t always limited to individual shoots and can spread back into plants to eventually encompass whole branches.  Entire plants dying from Bot Rot infection is not uncommon.   

While there aren’t any fungicides that are effective in controlling or preventing Bot Rot, gardeners can arrest its spread by pruning out infected branches.  To completely rid the plant of the fungus, make sure to prune 4” or so below the last infected plant tissue (symptomatic tissue will appear dark and discolored; healthy tissue will appear light and greenish).  After pruning each affected plant, it is important to sanitize pruning equipment with either a 10% bleach solution or 70%+ isopropyl alcohol to prevent spreading pathogens to other healthy plants!  Plants that have been irreparably disfigured by Bot Rot or outright killed may be pulled and discarded offsite. 

While this year’s Bot Rot infestation has been extremely frustrating and similar future freeze events can’t be ruled out, gardeners should not give up on Sweet Viburnum, an excellent specimen or screening shrub.  Keeping plants healthy with proper pruning, good fertility, and adequate irrigation is the best defense to ward off future infection when we experience harsh environmental conditions!  For more information on Bot Rot, Sweet Viburnum, or any other horticultural topic, contact your local UF/IFAS County Extension Office!  Happy Gardening.

Plant of the Week:  Camellia japonica

Plant of the Week:  Camellia japonica

Camellia japonica may be the quintessential Southern flowering plant, as it has decorated Southern landscapes with its giant winter flowers for over two centuries at this point.  It wasn’t always that way though.  The species took a long, winding road to the southern US, where it now enjoys its iconic garden status. 

Camellia japonica is a native of the mountainous regions of east Asia.  It was from there that “japonicas” were accidentally introduced to Europe in the late 1600s by British tea merchants, who mistook Camellia japonica for its very close cousin, the Tea Plant (Camellia sinensis).  After a century-long stay in England, Camellias then made their way to America around 1800.  As in England, Camellias were mostly grown as greenhouse flowering plants in the northern United States.  However, in 1843, Reverend John Drayton of South Carolina, brought camellias to his home, Magnolia Plantation, and popularized them outdoors in the Charleston area.  Many cultivars that are grown today trace their roots back to Rev. Drayton and Magnolia Plantation!

Camellia japonica ‘RL Wheeler’. Photo courtesy of Daniel Leonard.

Surviving every gardening fad and landscaping trend, Camellia’s popularity endures today for a couple of reasons.  First is their winter flower display.  Camellias provide a giant splash of color in an otherwise drab time of the year and there are literally thousands of japonica varieties in nearly every conceivable size, form, and color (provided you like white, pink, purple, and red) – there’s a camellia for everyone!  Camellias are also about as low maintenance a plant as can be found in landscapes.  It is not uncommon for camellias to persist in yards for generations without any help from gardeners.  After the establishment phase, camellias can go decades without supplemental water, fertilizer, or pesticide applications in many cases – especially if they are sited in an ideal spot.  Just plant these treasured passalong plants in a spot where water does not stand and that will receive some filtered or afternoon shade and enjoy the annual flowering show!

For more information on growing camellias, sourcing camellia plants for sale, or any other gardening topic, contact your local UF/IFAS County Extension Office.  Happy gardening!

A Nice Cup of…Camellia?

A Nice Cup of…Camellia?

Residents of North Florida are no doubt familiar with camellias, the large, glossy-green-leaved shrub that flowers during the cooler seasons. Common varieties include Camellia sasanqua, which blooms from October through December (depending on variety), and Camellia japonica, which blooms January through March. Both make huge, showy blossoms that demand attention, with forms that range from wild-rose-like to stunning geometric formal patterns.

The popularity of these shrubs is not in doubt, but a cousin of theirs takes the prize as one of the most popular plants in the world. Not due to its flowers: this variety of camellia does bloom, but the leaves are most interesting to humans. It is grown in dozens of countries worldwide and global production is estimated at over $17 billion worth of these leaves. The primary product made from this plant is a beverage that is consumed more than any other drink except water. It is, of course, tea.

Camellia sinensis or “Tea Plant”. Photo courtesy of UF/IFAS.

Camellia sinensis was named by botanist Carl Linnaeus, “Camellia” to honor another botanist, Rev. Georg Kamel, who really had nothing to do with the plant at all, and “sinensis”, which means “from China”. You may be able to deduce where tea is native to.

The tea plant prefers temperatures from 65 to 86 degrees Fahrenheit, doing well in zones 7-9. It can survive freezing or slightly-below-freezing temperatures, though leaves may be damaged by frost. It enjoys moist conditions, needing around 50 inches of rainfall per year. China tea (variety sinensis), which produces smaller, more serrated leaves, prefers more light than Assam types (variety assamica), which have larger, less serrated leaves. Either variety can be grown as a shrub or small tree.

Propagation may be accomplished either by seed or cuttings; cuttings are the preferred method for reproduction, as seeds must be germinated before the seed coat hardens for best results. Caring for tea plants once established involves more frequent but light fertilization, mulching, and regular scouting for pests. Camellia sinensis is susceptible to mites, thrips, scale insects, and aphids, all of which are present in large numbers in our area. Luckily, most of these problems can be solved with an application of either insecticidal soap or horticultural oil, if control is even necessary.

Once a tea plant is large enough to harvest leaves from, it is the new growth which is plucked. The top 2-3 leaves are used either fresh or fermented for a period of time before they are brewed. Green tea comes from the fresh leaves of China type tea plants, while either China or Assam types may be used to make black tea. Black tea leaves are picked, wilted or crushed, and allowed to ferment. Fermentation darkens the leaves and is halted by heating, which also serves to dry the leaves for storage.

For more information on the tea plant, see our EDIS publication on Tea Growing in the Florida Home Landscape.

Camellia sinensis foliage. Where the tea is made! Photo courtesy of UF/IFAS.
Autumn Brings Changes in our Landscapes

Autumn Brings Changes in our Landscapes

The shorter days and cooler temperatures of autumn bring on changes in our shrubs and trees.

Most people expect to see changes in leaf color in deciduous trees and shrubs during fall. But some people become concerned when the leaves on certain evergreen plants begin to turn yellow with the change in the seasons. For many plants this is normal.

Azaleas may lose a few leaves now. These are the older leaves on the branches near the center of the plant. There is no need for alarm by the loss of a few older azalea leaves from now until spring. However, if the younger leaves, those nearest the tip of the shoot, turn yellow or brown there is cause for concern. Poor drainage, lack of water or alkaline soils may cause this condition. Be sure to keep azaleas and other ornamental plants well-watered during dry weather that may occur from now through spring.

Other plants such as gardenias, hollies and camellias may have yellowing leaves now. But as with azaleas, these are the older leaves on the stem near the center of the plant. The mature leaves will drop from the plant from now until spring. This is only the normal aging of older leaves. However, be careful to not confuse this normal process with spider mites, scale, lace bugs, nutrient deficiencies, poor growing conditions or salt injury. Just keep in mind that this normal change in leaf color and leaf drop occurs on the older leaves generally during cooler weather – it’s a seasonal change.

Young red maple with fall foliage. Photo credit: Larry Williams

The leaves of sycamore trees have changed from green to brown by now. Although the sycamore is a deciduous tree, this phenomenon may not be caused by a change in day length or temperature alone. This change in leaf color in sycamores can begin in late summer. Many times, it is the result of sycamore lace bugs feeding on the leaves. By the time the damage is visible, there is little that can be done to correct the problem. However, this problem will take care of itself since sycamore trees will soon be dropping their leaves.

We do have some trees that exhibit beautiful fall foliage this time of year. A few to consider include hickory and gingko for their bright yellow fall foliage, black gum for its early display of brilliant red, purple or orange leaves and Chinese pistache for its late reddish-orange fall show. There are plenty of other good trees to consider for fall color here in North Florida such as dogwood, crape myrtle, Florida maple, sourwood, shumard oak and the list could continue.