Post Hurricane Landscape Care:  Replant Smartly with Hurricane Resistant Trees

Post Hurricane Landscape Care: Replant Smartly with Hurricane Resistant Trees

After a devastating windstorm, as we just experienced in the Panhandle with Hurricane Michael, people have a tendency to become unenamored with landscape trees.  It is easy to see why when homes are halved by massive, broken pine trees; pecan trunks have split and splayed, covering entire lawns; wide-spreading elms were entirely uprooted, leaving a crater in the yard.  However, in these times, I would caution you not to rush to judgement, cut and remove all trees from your landscape.  On the contrary, I’d encourage you, once the cleanup is over and damaged trees rehabilitated or disposed of, to get out and replant your landscape with quality, wind-resistant trees.

First, it’s helpful to take a step back and remember why we plant and enjoy trees and the important role they play in our lives.  Beyond the commercial aspect of farmed timber, there are many reasons to be judicious with the chainsaw in the landscape and to plant anew where seemingly sturdy trees once stood.  For example, trees provide enormous service to homes and landscapes, from massive cooling effects to aesthetic appeal.  Take this thermal satellite image of Hurricane Michael’s path that simultaneously shows the devastation of a major hurricane and the role trees play in the environment.

Lightly shaded area showing higher ground temperatures from loss of vegetation.

In the lighter colored areas where the wind was strongest and catastrophic tree damage occurred, the ground temperatures are much higher than the unaffected areas.  Lack of plant life is entirely to blame.  Plants, especially trees, provide enormous shading effects on the ground that moderate ground temperatures and the process of transpiration releases water vapor, cooling the ambient air.  Trees also lend natural beauty to neighborhood settings.  There is a reason people termed the hardest hit areas by Michael “hellscapes”, “warzones”, etc.  Those descriptions imply a lack of vegetation due to harsh conditions.  In this respect, trees soften the landscape with their foliage colors and textures, create architecture with their height and shape, and screen people from noise, unpleasant sights and harsh heat.

Though all trees give us the benefits outlined above, research conducted by the University of Florida over a span of ten major hurricanes, from Andrew to Katrina, shows that some trees are far more resistant to wind than others and fare much better in hurricanes.  In North Florida, the trees that most consistently survived hurricanes with the least amount of structural damage were Live Oaks, Cypresses, Crape Myrtle, American Holly, Southern Magnolia, Red Maple, Black Gum, Sycamore, Cabbage Palm and a smattering of small landscape trees like Dogwood, Fringe Tree, Persimmons, and Vitex.  If one thinks about these trees’ growth habits, broad resistance to disease/decay, and native range, that they are storm survivors comes as no surprise.  Consider Live Oak.  This species originated along the coastal plain of the Southeastern United States and have endured hurricanes here for several millennia.  Possessing unusually strong wood, they have also developed the ability to shed the majority of their leaves at the onset of storms.  This defense mechanism leaves a bare appearance in the aftermath but allows the tree to mostly avoid the “umbrella” effect other wide crowned trees experience during storms and retain the ability to bounce back quickly.  Consider another resistant species, Bald Cypress.  In addition to having a strong, straight trunk and dense root system, the leaves of Bald Cypress are fine and featherlike.  This leaf structure prevents wind from catching in the crown.  Each of the other listed species possess similar unique features that allow them to survive hurricanes and recover much more quickly than other, less adapted species.

Laurel Oak split from weak branching structure.

However, many widely grown native trees and exotic species simply do not hold up well in tropical cyclones and other wind events.  Pine species, despite being native to the Coastal South, are very susceptible to storm damage.  The combination of high winds and beating rains loosens the soil around roots, adds tremendous water weight to the crown high off the ground, and puts the long, slender trunks under immense pressure.  That combination proves deadly during a major hurricane as trees either uproot or break at weak points along the trunk.  In addition to pines, other widely grown native species (such as Pecan, Laurel Oak and Water Oak) and exotic species (such as Chinese Elm) perform poorly in storms.  Just as the trees that survive storms well possess similar features, so do these poor performers.  We’ve already mentioned why pines and hurricanes don’t mix well.  Pecan, Laurel Oak, and Water Oak tend to have weak branch angles and break up structurally in wind events.  The broad spreading, heavy canopy of trees like Chinese Elm cause them to uproot and topple over.  It would be advisable when replanting the landscape, to steer clear of these species or at least site them a good distance from important structures.

This piece is not a warning to condemn planting trees in the landscape; rather it is a template to guide you when selecting trees to replant.  Many of our deepest memories involve trees, whether you first climbed one in your grandparent’s yard, fished under one around a farm pond, or carved your initials into one in the forest.  Don’t become frustrated after a once in a lifetime storm and refuse to replant your landscape or your forest and deprive your children of those experiences.  As sage investor Warren Buffett once wisely said, “Someone is sitting in the shade today because someone planted a tree a long time ago.”

For these and other recommendations about how to “hurricane-proof” your landscape, contact your local UF/IFAS Extension Office.  Plant a tree today.

Algal Leaf Spot Common on Magnolias and Camellias

Algal Leaf Spot Common on Magnolias and Camellias

Algal leaf spot, also known as green scurf, is commonly found on thick-leaved, evergreen trees and shrubs such as magnolias and camellias.  It is in the genus Cephaleuros and happens to be one of the only plant parasitic algae found in the United States.  Although commonly found on magnolias and camellias, algal leaf spot has a host range of more than 200 species including Indian hawthorn, holly, and even guava in tropical climates.  Algal leaf spot thrives in hot and humid conditions, so it can be found in the Florida Panhandle nearly year round and will be very prevalent after all the rain we’ve had lately.

Symptoms

Algal leaf spot is usually found on plant leaves, but it can also affect stems, branches, and fruit. The leaf spots are generally circular in shape with wavy or feathered edges and are raised from the leaf surface. The color of the spots ranges from light green to gray to brown.  In the summer, the spots will become more pronounced and reddish, spore-producing structures will develop. In severe cases, leaves will yellow and drop from the plant.

Algal Leaf Spot

Algal leaf spot on a camellia leaf. Photo Credit: University of Florida/IFAS Extension

The algae can move to the stems and branches in more extreme cases. The algae can infect the stems and branches by entering through a small crack or crevice in the bark. The bark in that area cracks as a canker forms that eventually can girdle the branch, killing it.

Algal Leaf Spot on a Stem

Algal leaf spot on a sycamore branch. (Platanus occidentalis). Photo Credit: Florida Division of Plant Industry Archive, Bugwood.org.

Management

In most cases, algal leaf spot is only an aesthetic issue. If only a few leaves are affected, then they can just be removed by hand.  \It is important that symptomatic leaves are discarded or composted offsite instead of being left in the mulched area around the trees or shrubs. If symptomatic leaves are left in the same general area then irrigation or rain water can splash the algal spores on healthy leaves and branches. Infected branches can also be removed and pruned.

Preventative measures are recommended for long-term management of algal leaf spot. Growing conditions can be improved by making sure that plants receive the recommended amount of sunlight, water, and fertilizer. Additionally, air circulation around affected plants can be increased by selectively pruning some branches and removing or thinning out nearby shrubs and trees. It is also important to avoid overhead irrigation whenever possible.

Fungicide application may be necessary in severe cases. Copper fungicides such as Southern Ag Liquid Copper Fungicide, Monterey Liqui-Cop Fungicide Concentrate, and Bonide Liquid Copper Fungicide are recommended. Copper may need to be sprayed every 2 weeks if wet conditions persist.

Algal leaf spot isn’t a major pathogen of shrubs and trees, but it can cause significant damage if left untreated. The first step to management is accurate identification of the problem.  If you have any uncertainty, feel free to contact your local Extension Office and ask for the Master Gardener Help Desk or your County Horticulture Agent.

The ‘Star’ of Magnolias

The ‘Star’ of Magnolias

Magnolias are well known plants to gardeners and many are familiar with the foliage and flowers of these plants. If you are looking for another earlier bloomer, you may want to consider adding a specimen selection to your landscape, the Star magnolia (Magnolia stellata).

 

Although not native to the United States, star magnolia is a slower growing multi stemmed deciduous shrub reaching about 15 feet in height over time. The best feature are the bright whitish pink star-shaped blooms appearing in late winter before leaves emerge.  The flowers offer gardeners a peek of the spring to come and remind us that our Gulf Coast winters are not that long. DSC_0065

Plants do best in soil with some organic amendments and mulch over the root systems. A planting area that receives a little afternoon shade is ideal but established plants will adapt to sunnier locations when irrigation is provided during drier weather.  Only occasional pruning is required to remove crossing branches or those that grow out of bounds.  Prune after flowering if needed.

Late-flowering Magnolias Avoid Freeze Damage

Late-flowering Magnolias Avoid Freeze Damage

‘Jon Jon’ magnolia

This winter’s recurring freezes and frosts have played havoc with early flowering plants like magnolia. While buds are freeze-resistant, open magnolia flowers can quickly turn brown after exposure to temperatures about 30°F or lower. One way to avoid freeze-damaged flowers is to choose later blooming cultivars. These selections have flowers that open in north Florida during late February or later.

 

The Magnolia Garden at the University of Florida/IFAS North Florida Research and Education Center (NFREC) in Quincy has more than 150 types of magnolias planted. Based on over 10 years of data, five of the latest blooming magnolias are Daybreak, Jane, Betty, Jon Jon and Ann. These cultivars have peak bloom dates ranging from late February (Ann) to mid-March (Daybreak). Thus, they bloom after most flower-damaging freezes.

 

Daybreak has beautiful, large shell-pink flowers on a small tree. Jon Jon has huge white flowers with a streak of red-purple at the base. These fragrant flowers open goblet-shaped the first day, and then open wider to a cup-and-saucer shape on subsequent days. At NFREC, Daybreak and Jon Jon have about 6 weeks of flowers and grow as single-stem or multi-stem trees up to about 30 feet tall.

 

Jane, Betty and Ann are sister cultivars developed at the National Arboretum. As you would expect with sisters, they look-alike, and have a shrubby or multi-stemmed tree habit, generally growing about 15 feet tall and wide (much shorter and wider than Daybreak and Jon Jon). All three have upright, cup-shaped flowers in various shades of pink and red-purple. Betty has medium red-purple flowers that are the largest of the three, over 4 inches. Jane has 3- to 4-inch flowers that are medium pink outside and white or pale pink inside. Ann has the smallest flowers (3 inches) but they are also the darkest red-purple. As an added bonus, Ann boasts the ability to produce sporadic flowers all summer long! This results in Ann having an average of 13 weeks of flowers, as compared to Jane’s 10 weeks and Betty’s 8 weeks.

 

These five cultivars are generally available at garden centers during spring. Ann and Jane can be found at many “Big Box” stores. All five can be purchased at “good” independent garden centers and, as a last resort, from mail-order/Internet nurseries.

 

For more information about these and other magnolias, see Florida Extension publication, ‘Jon Jon’ Magnolia: A Late-Flowering Deciduous Magnolia for Northern Florida, and other magnolia publications here. Also, Magnolia Society International is a great resource with a very informative website. (Note the slide show below of Jon Jon, Ann, Betty, Daybreak and Jane.)

 

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Evergreens for Holiday Decorating

Evergreens for Holiday Decorating

Now that we’ve all been stuffed like a Thanksgiving turkey, it’s time to transition into the final and, arguably, most ornate holidays of the year. Right now you can hear your mantles and door frames crying out to be adorned. Your windows are begging for wreaths and giant red bows. And there may be a certain corner in your house that has been waiting all year for an evergreen, or two.

As we delve into the winter holidays our homes are being dressed to impress. There is nothing better than fresh foliage placed along a mantle or maybe a little mistletoe hanging from a previously unadorned beam. The scent of pine is in the air and I don’t know about you, but I’m ready to get decorating.

Here is a list of a few evergreen plants that make wonderful decorations for the season. You may even find some in your own backyard! Just make sure when you are removing foliage and fruit that you do it gently, so as not to harm the plant. Make all cuts at a 45 degree angle so that water will not pool on branch tips and rot. Also, if you forcefully remove foliage from a plant you could expose the susceptible cambium layer.

Wreaths and a decorated door frame add a bit of holiday cheer to this snowy scene. Photo courtesy Taylor Vandiver.

Wreaths and a decorated door frame add a bit of holiday cheer to this snowy scene. Photo courtesy Taylor Vandiver.

Traditional

Magnolia (Magnolia grandiflora) – This southern staple provides foliage that will liven up any banister or door frame. After being cut from the tree it can withstand the dryer temperatures indoors for days on end. 

Hollies (Ilex spp.) – Hollies not only provide glossy green foliage, but bright red fruit that will beautifully adorn holiday arrangements and centerpieces. 

Pine/Pinecones (Pinus spp.) – Pine trees offer a wispy presence to many decorations and their cones can give structure to wreaths and mantle pieces. 

Boxwood (Buxus spp.) – Boxwoods are great for a touch of green.

Yaupon holly fruit and foliage. Photo courtesy UF/IFAS.

Yaupon holly fruit and foliage. Photo courtesy UF/IFAS.

New Ideas

Abelia (Abelia x grandiflora) (evergreen to semi-evergreen) – Abelia are not commonly thought of when making holiday arrangements, but the texture of their foliage and the myriad of colors can spice up traditional decorations. 

Aucuba (Aucuba japonica) – Aucuba offer a coarse texture that would pair well with the wispier pine foliage. Also, the gold dust variety will add a little more color to the mix.

Aspidistra (Aspidistra elatior) – Aspidistra foliage tends to feel more tropical. If you want to try a non-traditional arrangement these would work well and they can last for days provided a small amount of water. 

Aspidistra foliage that could easily be worked into a stunning arrangement.

Aspidistra foliage that could easily be worked into a stunning arrangement.

Remember that a few well placed planters can liven up even the smallest spaces. Try using a small evergreen tree or shrub such as a magnolia, cypress / false cypress or arborvitae and surround them with poinsettia or pansies. You can try a smaller planter and add in pine cones, poinsettia, grasses, etc. Also if you are celebrating this holiday season with a live Christmas tree, then don’t be afraid to ask the grower/retail center for discarded branches. These can easily be formed into a wreath or used throughout the house. And since this is Florida there’s always the option of decorating your palm tree!

Gardens of the Big Bend: A New Botanical and Teaching Garden in North Florida

Gardens of the Big Bend: A New Botanical and Teaching Garden in North Florida

View of the Discovery Garden in Gardens of the Big Bend.

View of the Discovery Garden in Gardens of the Big Bend.

Weeping false butterflybush, Rostrinucula dependens, is a new and unusual perennial being evaluated in Gardens of the Big Bend.

Weeping false butterflybush, Rostrinucula dependens, is a new and unusual perennial being evaluated in Gardens of the Big Bend.

Gardens of the Big Bend is a new botanical and teaching garden located on the grounds of the University of Florida/IFAS North Florida Research and Education Center in Quincy. The goals of these gardens are to evaluate new plants, promote garden plants adapted to the region, demonstrate environmentally sound principles of landscaping and provide a beautiful and educational environment for students, visitors, gardeners and Green Industry professionals.Located just 10 miles south of the Georgia-Florida border in Florida’s “Big Bend,” the Gardens are in USDA Cold Hardiness Zone 8b and have sandy-clay soils more typical of continental conditions than those of peninsular Florida.

Gardens of the Big Bend is a series of gardens, each with a theme or plant focus:

  • The Discovery Garden contains over 170 species or cultivars of new, improved or underutilized trees, shrubs and perennials. The garden’s purpose is to help gardeners, landscapers and nursery growers “discover” new plants.
  • The Magnolia Garden is part of the National Collection of Magnolia in recognition of its’ more than 200 species and cultivars, including some of the rarest magnolias in the world.
  • The Crapemyrtle Garden includes six species and over 100 cultivars.
  • Conifers can be found throughout the Gardens but are featured in the new “Jurassic” garden. More than just pines and junipers, the Gardens contain over 50 conifer species and cultivars, many of which are rare. In recognition, the American Conifer Society has designated the Gardens as a “Conifer Reference Garden”, the only one in Florida, and the southernmost in the U.S.
  • The Dry Garden is the newest addition and contains about 140 different types of agave, aloe, cactus, dyckia, sedum, yucca, bulbs and other dry-adapted plants. It consists of a south-facing berm of boulders, gravel and sand about 160 feet long, 35 feet wide and 6 feet tall.
  • Other gardens feature native, shade, Southern heritage, and weeping plants as well as collections of Japanese hydrangea and shrub roses. Additional gardens will be installed as time and funding permit.
Parana pine, Araucaria angustifolia, is a rare type of conifer in the Gardens.

Parana pine, Araucaria angustifolia, is a rare type of conifer in the Gardens.

Gardens of the Big Bend formally began in 2008 thanks to the happy marriage of a new volunteer organization coupled with this University of Florida off-campus facility and plant collections I developed as part of research and extension projects. The volunteer organization, Gardening Friends of the Big Bend, Inc., formed in 2007 to support horticulture research and education. This group quickly seized on the idea of transplanting these existing plant collections into a series of gardens. Accordingly, its members hold fundraisers, provide volunteer labor and sponsor extension programs to raise awareness, provide funds and support garden development and maintenance.

Gardens of the Big Bend is located in Quincy at I-10 Exit 181, just 1/8 mile north on Pat Thomas Highway (SR 267). The gardens are free and open to the public during daylight hours year-round; professional staff are only available during normal business hours. To make a gift to the Gardens, please go to this website! Come visit us and watch the Gardens grow!