by Gary Knox | Jul 30, 2020
The dog days of summer are here with high temperatures and humidity. While this sultry weather forces humans to retreat to air conditioning, our gardens suffer because the high night temperatures cause temperate plants to stop flowering, lose vigor and pause growth. By August, many plants in the garden look as bedraggled and wilted as we feel after mowing the grass or trying to weed.
‘Moy Grande’ Hardy Hibiscus (Hibiscus spp.)
All is not lost: the fading flowers and fizzling foliage of traditional garden plants can give way to heat-loving tropicals! Plants that are native to tropical and subtropical climates are naturally adapted to heat, humidity and rain, easily standing up to the worst that our north Florida summers can throw at them. Tropicals offer bright flowers, bold texture and exuberant growth just when the rest of your garden melts in the heat. Tropical plants include trees, shrubs, vines, perennials, groundcovers or annuals, and there are tropicals for full sun, part sun or shade.
Tropical Plants for North Florida
Top tropicals for north Florida gardens are palms, bananas, hibiscus, and gingers. Palms are the iconic symbol of the Tropics. Native subtropical palms can give you the palm vibe without the worry of cold hardiness. These include cabbage palm and related palmettos in the genus Sabal, paurotis palm (Acoelorrhaphe wrightii), saw palmetto (Serenoa repens) and needle palm (Rhapiophyllum hystrix). Non-native European fan (Chamaerops humilis), jelly (Butia spp.), windmill (Trachycarpus spp.), date (Phoenix spp.), Washington (Washingtonia spp.) and other palms also grow well and are cold hardy in north Florida. Most palms grow best in full to part sun but palmettos, saw palmetto and needle palm can handle more shade. Saw palmetto, needle palm and most palmettos grow 3 to 6 ft. tall. European fan, jelly, paurotis and windmill palms grow 10 to 20 ft. tall, while cabbage, Washington and date palms often exceed 40 ft. For best appearance, palms often require special fertilizer (https://edis.ifas.ufl.edu/ep261).
Hardy Yunnan Banana (Musa yunnanensis)
Characterized by their large, bold leaves, bananas are another plant group associated with tropical weather and full sun. Hardier forms of banana that thrive here include Chinese yellow (Musella lasiocarpa), pink (M. velutina), basjoo (Musa basjoo), Yunnan (M. itinerans), and hardy Yunnan (M. yunnanensis). Chinese yellow and pink bananas grow about 5 ft. or more in height, whereas the others have mature heights of 20 ft. or more. Bananas benefit from planting in a location that blocks strong winds so as not to shred the leaves. Depending on the severity of our winter, these bananas may lose some or all leaves but they usually regrow in late spring once warm weather arrives.
The large, colorful and exotic-looking flowers of tropical hibiscus (Hibiscus rosa-sinensis) are associated with the tropics, though this hibiscus is less cold hardy here and is perhaps best enjoyed as a container plant. Other notable hibiscus for north Florida include Confederate rose (H. mutabilis), rose-of-sharon or althea (H. syriacus), and hardy hibiscus (many hybrids of H. moscheutos and other native species). Varying in height from 3 (hardy hibiscus) to 12 ft. (confederate rose), hibiscus thrives in full sun and moist, even wet, soil. Their summer flowers come in colors of white, lavender, pink and red and range in size from a few inches (althea) to the size of dinnerplates (hardy hibiscus)! Except for rose-of-sharon, these hibiscus die back in winter and re-emerge again in late spring.
‘Disney’ Ginger Lily (Hedychium coccineum)
Gingers are also symbolic of the tropics. Many produce complex or colorful flowers and often flowers or other plant parts are aromatic. Ginger lily (Hedychium spp.), spiral ginger (Costus spp.) and shell ginger (Alpinia spp.) have fragrant and colorful racemes or spikes of flowers that appear at the tops of stems 4 ft. to 6 ft. or more tall. Hidden ginger (Curcuma spp.) and true ginger (Zingiber spp.) are lower growing with flowers appearing in “cones” on tops of separate, short stems. Finally, the patterned leaves of peacock ginger (Kaempferia spp.) make a beautiful summer groundcover. Gingers grow best in part sun to part shade.
There are many other tropical plants including coral tree (Erythrina × bidwillii and E. crista-galli), pride-of-barbados (Caesalpinia pulcherrima), fatsia (Fatsia japonica), selloum philodendron (Thaumatophyllum bipinnatifidum), canna lily (the non-invasive Canna × generalis hybrids), peregrina (Jatropha integerrima), elephant ear (non-invasive Alocasia spp. types), Begonia spp. (annual, angelwing and rhizomatous types) and Caladium selections. Bamboos have a tropical look, but many grow aggressively and may be invasive in north Florida. Two recommended clumping bamboos are common bamboo (Bambusa vulgaris; growing 15 ft or more tall) and Chinese garden bamboo (Drepanostachyum falcatum; growing 12 ft. or more tall).
Cockspur Coral Tree (Erythrina crista-galli)
“Tropical” does not necessarily mean “non-native” as there are many Florida natives that provide summer color or texture and are heat loving yet cold hardy in north Florida. These include some palms (cabbage, palmetto, paurotis), ashe magnolia (Magnolia ashei), switchcane (Arundinaria gigantea, a native bamboo), hardy hibiscus (Hibiscus grandiflorus, H. moscheutos and others), golden canna (Canna flaccida), and maypop passionflower (Passiflora incarnata).
Disadvantages of Tropicals
Use of tropicals in your garden does have a downside. Most tropicals are water hogs and need regular irrigation. This isn’t a problem if our area experiences the normal patterns of summer thunderstorms. However, if we don’t receive regular rainfall, tropical plants create the burden of having to water them regularly or else their flowers wilt and leaves droop.
Another disadvantage of tropicals is the “off-season” appearance. Though they thrive in summer heat, they grow slowly during the cooler temperatures of spring and fall and some disappear altogether in winter. Some tropicals are not winter hardy in north Florida and must be replanted each year or undergo elaborate cold protection strategies to help them survive. Other tropicals will over-winter, but often are burned back by frosts, requiring labor to cut back the dead foliage and stems. Finally, tropicals usually require warm weather for growth to resume, and tropicals that die back will produce gaps in your landscape during winter, spring and early summer.
‘Portora’ Giant Elephant Ear (Alocasia sp.)
At the other extreme, some tropicals have such exuberant growth that they are invasive in north Florida. For example, almost all running types of bamboo and many clumping bamboos are invasive, other than those mentioned previously. Also avoid non-native canna (Canna indica), elephant ears (Colocasia and Xanthosoma spp.), Lantana (sterile forms are OK), and some non-native passionvines (Passiflora spp.). If you have questions about a plant’s invasiveness, check the UF/IFAS Assessment of Non-Native Plants in Florida’s Natural Areas, https://assessment.ifas.ufl.edu/.
Using Tropicals in North Florida
Tropicals are best used as accent plants to draw attention in summer when they look their best and the rest of the garden looks its worst. When used as accents, place them throughout the landscape so that winter damage or absences aren’t noticed. Concentrations of tropicals in one area will look great in summer but could look like a mass of dead foliage in winter! To create an entirely tropical-looking planting in north Florida, combine tropical plants with cold-hardy tropical lookalikes (a topic for another time!).
Plant tropicals in late spring once temperatures warm because they will grow slowly or even experience damage at temperatures below 50°F. Best practices for tropicals are to place them in the appropriate exposure for the particular plant (sun, part sun or shade) and keep them mulched. One common characteristic of tropicals is their need for soil moisture, necessitating irrigation to supplement rain. A rich soil or applications of organic mulches or compost can provide nutrients for growth, or light fertilizer applications in summer can boost growth.
Tropicals come alive in the heat of summer. When used in north Florida gardens, tropical plants provide pops of color, luxuriant growth and big, bold, dramatic texture that rescue our gardens from the doldrums of summer!
by Stephen Greer | Jul 16, 2020
By: Stephen Greer, CED Santa Rosa County
Rhexia marianna Photo credit: Stephen Greer, University of Florid IFAS
There is a lot to be said about early morning or late afternoon walks along a woodland trail in Northwest Florida. With so much to see, hear and smell there is never enough time to take it all in. I would suggest slowing down and look for the many colorful and interesting plants these native plant communities have to offer.
I had the great fortune to meet with a group of plant explores lead by Angus Gholson, botanist and conservationist with a passion to share his knowledge in Washington County many years ago for a 5-hour hiking adventure. We hiked an exceptional longleaf pine forest with immense flora on the forest floor. It was all but impossible to see everything.
We searched for unique and common plants in the Sandhills and Clayhills in the central and northern areas of Washington County. Here are just a few of the plants we saw along our hike and some detail about them.
St. Peter’s-wort. Photo create: Stephen Greer University of Florida IFAS
St. Peter’s-wort, Hypericum tetapetalum is a wonderful Hypericum of the many we have in NW Florida. With its ability to repeat bloom petite yellow flowers from March to November, we often get the chance to revisit these trails at a later date for another chance to enjoy them. Like many repeat blooming natives, there will be weeks of rest periods with no bloom. This shrub will grow to three feet tall allowing the flowers to peak out over other plants in the pine flatwoods.
Shiny Lyonia, Lyonia lucida is another exceptional shrub with many uses. This evergreen can grow in low damp areas or with irrigation in landscapes to 10 to 12 feet tall. When found in pine forest areas they range from 3 – 6 feet tall. This Lyonia produces an attractive small bell-shaped red flower spread across a stem of last years growth similar to blueberry. Flowering can occur between November and June.
Lyonia lucida. Photo credit: Stephen Greer, University of Florid IFAS
Pale Meadow Beauty, Rhexia Marianna brings a soft pink bloom to the pine forest, grass prairies and edge of full sun to part-shade wetlands. With the ability to grow in diverse landscapes in Northwest Florida it can just about show up anywhere, bloom a few weeks and melt back into the natural setting. Seeding is best completed in the fall and consistent moisture is needed for bloom to occur.
All three of the plants in this article can be found at native plant nurseries. Call the nursery well ahead of time to make sure they either have it or can order it for you. Enjoy the outdoors and adventure it has to offer.
by Julie McConnell | Jul 16, 2020
We hope you were able to join us for Gardening in the Panhandle LIVE! Butterfly Gardening on July 9th to learn about attracting butterflies to your Florida gardens. As promised, we have compiled a list of butterfly resources that we talked about during the webinar and a few extra that we didn’t have time to cover.
If you were not able to join us live, you can still watch the videos on Facebook or YouTube
Click on the topic of interest for links to resources:
Don’t forget to tune in for our next Gardening in the Panhandle LIVE! on July 23rd for Prepping for the Fall Garden. Register for that webinar on Zoom or Follow our Facebook Event for updates.
For a full list of upcoming webinars visit Gardening in the Panhandle: LIVE!
by Carrie Stevenson | Jun 4, 2020
Sundews, tiny carnivorous plants found in pitcher plant bogs, use an enzyme dissolve insect proteins. Native Americans recognized this property and used the plant for skin maladies. Photo credit: Carrie Stevenson, UF IFAS Extension
There are few words better than “pure delight” to describe the face of someone who sees and appreciates a sundew for the first time. Maybe it is their size—often no bigger around than a quarter—or the miniature pinwheel shape, but sundews could easily fit into a fable about garden gnomes or fairies in the woods. These tiny plants hide in plant sight–so small and flush to the ground that you likely won’t see them unless specifically looking for them. But, once you are looking in the right conditions, you will probably see them everywhere.
Sundews (Drosera spp.) are small carnivorous plants found in the same bogs as pitcher plants. They thrive in moist, mucky soil and full sun. They are also carnivorous for the same reasons pitcher plants are—their wet, acidic habitats possess few soil nutrients, so they use insects instead.
Sundews utilize a different method for trapping insects—their flat, radiating structure has wider lobes on the ends, which are covered with hairlike tentacles. These hairs secrete droplets of sticky sap visible at the tip of each hair. Small insects are attracted to the dewlike sap and get stuck. The hairs curl around the insect like a slow Venus flytrap, and natural enzymes to break down the bug.
A healthy sundew plant growing just above the water level at Boiling Creek in Santa Rosa County. Photo credit: Larry Burner, Florida Master Naturalist
There are almost 200 species of sundews, not all with the flat growth pattern. The threadleaf sundew has an upright structure, while others may grow in a spherical shape at the water’s edge. While paddling Boiling Creek on Eglin Air Force Base property a few years ago, our group saw dozens of sundews growing on the trunks of cypress and tupelo trees at eye-level from our kayaks. They were about 4-6” in diameter, much larger than the 1” ones we typically see in the bogs.
Tarkiln State Park, Weeks Bay National Estuarine Research Reserve, or any place you find pitcher plants are a great place to find sundews. You may have to get on your knees to see them, and move the grasses aside. Bring a hand lens to magnify the delicate details of the droplets of sap perched at the tip of tiny hairs.
Even the famous naturalist Charles Darwin was enthralled with sundews, conducting experiments and writing volumes about them. In an 1860 letter to his geologist friend Charles Lyell, Darwin stated that, “at the present moment, I care more about Drosera than the origin of all the species in the world.” If you, too, are fascinated with carnivorous plants, check out these resources from UF IFAS Extension and the Botanical Society of America.
by Carrie Stevenson | Jun 4, 2020
Fig. 1 An adult redbay ambrosia beetle compared to the size of a single penny. Credit: UF/IFAS File Photo.
While most bark beetles are important in forest ecology by recycling fallen dead trees and eliminating sick and damaged trees, some of them may impact healthy trees. A group of bark beetles that has become a major concern to forest managers, nurseries, and homeowners is the ambrosia beetle. Ambrosia beetles are extremely small, 1-2 mm in length, and live and reproduce inside the wood of various species of trees (Fig. 1). Ambrosia beetles differ from other bark beetles in that they do not feed directly on wood, but on a symbiotic fungus that digests wood tissue for them. Every year, non-native species of ambrosia beetles enter the United States through international cargo and we have now nearly forty non-native species of ambrosia beetles confirmed in the United States. Among them, the redbay ambrosia beetle (Xyleborus glabratus), originally from Southeast Asia, is the vector of the fungal pathogen causing laurel wilt, a disease that devastated the Lauracaea population in the southeastern USA, killing millions of redbay, swamp bay, sassafaras and silk bay.
Fig. 2: A mature dooryard avocado tree with large sections of dead and missing leaves, caused by laurel wilt disease. Summer 2009 Impact Magazine image. Credit: UF/IFAS File Photo.
When these beetles attack a laurel tree, the symbiotic fungus is vectored to the tree’s sapwood after the beetle has tunneled deep into the tree’s xylem, actively colonizing the tree’s vascular system. This colonization leads to an occlusion of the xylem, causing wilting of individual branches and in a matter of weeks progresses throughout the entire canopy, eventually leading to tree death (Fig. 2). The laurel wilt disease has spread rapidly after the vector was first detected in Georgia in 2002. The redbay ambrosia beetle was first detected in Florida in 2004, in Duval County, attacking redbay and swamp bay trees. At this point, it is estimated that more than one-third of redbay in the U.S.A., 300 million trees, have succumbed to the disease.
Starting in 2017, we examined the efficacy of verbenone against redbay ambrosia beetle in live laurel trees in a natural forest setting. Verbenone is an anti-aggregation pheromone that has been used since the 1980’s to protect lodgepole pine. Verbenone also has the potential to be used over large areas and is currently being used to protect ponderosa pine plantations from the Mountain Pine Beetle in the western US.
We have found verbenone to be an environmentally friendly and safe tool to prophylactically protect laurel trees against redbay ambrosia beetle. Our protocol consists of the application of four 17 g dollops of a slow-release wax based repellent (SPLAT Verb®, ISCA technology of Riverside, CA) to the trunk of redbay trees at 1 – 1.5 m above ground level (Fig. 3). The wax needs to be reapplied every 4 months during fall and winter and every 3 months during spring and fall when temperature is higher. When compared to the control trees without repellents, we found that trunk applications of verbenone reduced landing of the redbay ambrosia beetle on live redbay trees and increased survivorship of laurel trees compared to untreated trees (Fig. 4). Verbenone should be considered as part of a holistic management system against redbay ambrosia beetle that also includes removal and chipping of contaminated trees.
If you have Redbay or other bay species on your property and are concerned about Laurel Wilt Disease or Redbay Ambrosia Beetle damage, contact your local UF/IFAS Extension Agents for help!
This article is courtesy of Dr. Xavier Martini and Mr. Derek Conover of the UF/IFAS North Florida Research and Education Center (NFREC) in Quincy.
Fig. 3: Application of SPLAT Verb on a redbay tree during a field trial
Figure 4: (A): Cumulative capture of redbay ambrosia beetles Xyleborus glabratus following a single application of verbenone vs untreated control (UC). (B) Survivorship of redbay and swamp bay trees treated with verbenone on four different studies conducted in 2017 and 2018.
by Larry Williams | May 14, 2020
When we go through dry periods in North Florida some residents become interested in drought-tolerant plants to include in their landscapes. The need for irrigation can be reduced when drought-tolerant plants are used. But don’t overuse these plants. Remember we have periods of rainy weather, too.
Gulf Muhly Grass in Flower. Photo credit: Larry Williams
Some drought-tolerant plants have poor tolerance to the other extreme – too much water. There are a few plants that can tolerate both extremes but they are the exception. Avoid using drought-tolerant plants on naturally wet or poorly drained sites. But if you have the typical deep sandy well drained soil Florida is famous for, you’d do well to include some drought-tolerant plants on your site.
Drought-tolerant plants are especially well suited for areas that receive little to no irrigation.
Some plants are genetically better able to withstand drought. They have a built-in tolerance of drought. Many of our Florida native plants are designed to grow in our poor water holding sandy soils. Many of the plants native to arid areas of the world possess high drought-tolerance. These plants have characteristics that allow them to better survive dry weather. These features include thicker or waxier leaves, large surface root areas or deep roots and the ability to drop leaves in drought and regain them when moisture is adequate.
Beautyberry with fruit. Photo credit: Larry Williams
It’s important to realize that these plants must first establish a root system before they can cope with severe dry weather. Plan to irrigate during dry periods for the first season to allow them to become established.
Some outstanding trees to consider include crape myrtle, redbud, Chinese pistache, cedar (Cedrus species), hawthorn (Crataegus species), American holly, yaupon holly, Southern red cedar (Juniperus species), Live oak, Sand live oak, winged elm, pond cypress and bald cypress. Some people are surprised to learn that pond cypress and bald cypress have high drought-tolerance because these trees are associated with swamps, many times growing in standing water. But once established on a dry site, they exhibit very good drought-tolerance.
Some outstanding shrubs with drought-tolerance include glossy abelia, dwarf yaupon holly, Indian hawthorn (Rhaphiolepis species), beauty berry (Callicarpa americana), pineapple guava, junipers, oleander, spiraea, blueberry or sparkleberry (Vaccinium species), viburnum, Chaste tree (Vitex agnus-castus) and coontie (Zamia pumila).
Pineapple guava in bloom. Photo credit: Larry Williams
Some outstanding drought-tolerant groundcovers to consider include beach sunflower (Helianthus debilis), daylily, juniper, lantana, liriope, rosemary (Ceratiola ericoides), Asiatic jasmine and society garlic. Many of the ornamental grasses such as Gulf muhly are good choices as well.
For more ideas on developing a Florida-friendly, water wise landscape, contact the UF/IFAS Extension Office in your County or visit the below website. https://ffl.ifas.ufl.edu/index.html
