Category: Blog

In the Coastal Southeast, it is possible to grow several cold-hardy members of tropical plant families in the landscape. The addition of some bold textured hardy plants and a few fast-growing tropical plants as annuals can create a tropical rainforest look despite our relatively cold winters.

Cold hardy species that grow into zone 8 can be found in the following plant groups.
aroid
bamboo 
banana 
begonia
bromeliad 
cycad 
ginger 
hibiscus 
palm 
pandanus 

Other tropicals with some cold hardiness
Acacia 
Bauhinia – orchid tree
Bletilla
Brugmansia – angel’s trumpet
Caesalpinia
Calliandra 
Cordia 
Cordyline 
Cyathea
Cymbidium
Epidendrum 
Erythrina 
Excoecaria
Galphimia 
Hamelia 
Havardia 
Jacaranda 
Lysiloma 
Megaskepasma 
Montanoa
Musella 
Mussaenda
Odontonema 
Phaius 
Philodendron
Pseudobombax
Schefflera 
Solanum
Sophora 
Stachytarpheta – porterweed
Strelitzia 
Tabebuia 
Tacca – bat flower
Thysanolaena 
Tibouchina 
Tithonia diversifolia – giant daisy
Zanthoxylon 

Cold hardy plants (into zone 8) with bold, tropical-looking foliage. 
Aspidistra
Canna
Crinum 

Cold tender tropical plants that serve well as annuals
Acalypha hispida (in the photo at the top of the page) 
Acalypha armenatacea 
Allamanda 
Breynia – snow bush
Carica – papaya
Codieaum variegatum – croton
Euphorbia cotinifolia – Caribbean copperleaf
Holmskioldia 
Leea 
Mahinot 
Pachystachys
Pentas 
Plumbago 
Sanchezia
Spathoglottis
Thunbergia grandiflora

useful references:
Creating the Tropical Look by Texas A&M University

This is large genus of succulent plants native to Asia, Europe and North America. They are variable in size, leaf shape and flower color but the flowers are always five-pointed stars in clusters at the top of the stem. One odd problem that I have is that something eats the leaves in winter, chewing the tips first. It may be rodents or birds in search of moisture.

Crassulaceae, is a large family that is native to Asia, Africa, Europe and North America. Many of them have succulent leaves. Many species are cultivated as plants for the house and garden. Familiar members of this family include the jade plant (Crassula,) ghost plant (Graptopetalum,) kalanchoe (Kalanchoe) and hen-and-chicks (Sempervivum.)

The large succulent leaves of this robust Mexican plant are green with an orange to brownish cast when grown in bright light. It is a bushy plant in bright light. In shade, stems tend to trail. White flowers are borne on leafy stalks at the stem tips. Give it a sunny site with afternoon shade in a well-drained site or container. Reportedly, it is cold hardy in zones 8b and south. 

 Sedum nussbaumerianum is similar but oranger in color when grown in the sun and its stems are less upright. Some botanists believe that the two should be lumped under the name S. adolphii. 

This plant may be found in specialty catalogs. It is propagated easily by stem cuttings and by single leaves.

I move my plant under a roof in winter to minimize exposure to rainfall. It survives winter lows in the low 20’s F with little damage but a low of 18 degrees caused the death of some of the stems. My plant flowers in February. The developing flower buds tolerated winter temperatures in the low 20’s F without damage.

Despite its name, the origin of this species is not known. Some botanists believe it is native to Asia. At a glance, it resembles Sedum acre. In comparison, it is a more compact plant with smaller leaves. Its short stems do not trail along the ground and it seems much better adapted to the Coastal Southeast. It bears clusters of tiny yellow flowers at the stem tips in spring. It grows well for me in a well-drained soil, in a sunny site with afternoon shade. It requires more water than most of my succulents. It is recommended for zone 7 to 9.

Plants are available from specialty catalogs. It is propagated easily by stem cuttings.

My plants grow very well in a container with weekly watering. It has grown poorly in an unirrigated site in the ground in my garden. They flower in April and early May. They have survived winter lows of in the upper teens F without obvious damage.

I am have tried a few other stonecrops and continue to buy more. Many seem to benefit from afternoon shade and regular water in my zone 9a garden.

Sedum dendroideum is a Mexican species. It is a somewhat bushy plant that can grow to two feet tall or more. It resembles a jade plant (Crassula ovata) but its stems are more flexible and slender than a jade plant’s. It is reported to be cold hardy to 20° F. A young plant showed no damage on my porch when temperatures dropped into the low 20’s. I have not tried it yet but S. prealtum is reported to be similar with even greater cold hardiness.

Sedum pachyphyllum is another Mexican species that I tried. It is a spreading plant with fat, rounded leaves. It is reported to be cold hardy to 15°  F. It required more water than most of my succulents and eventually died from my neglect.

Sedum palmeri has flattened, blue-gray leaves. Reportedly, it is cold hardy to zone 7a. Mid- to late winter flowers are bright yellow. I have grown this species in a container for years. In my zone 9a garden, this has been the most dependable of the spreading sedums. It shows no problems when winter lows drop to the upper teens but the leaves of this plant suffer from whatever is chewing stonecrop leaves in my garden.

Sedum rupreste (syn. Sedum reflexum), the blue spruce sedum has grown well at the University of North Florida in a container of good potting soil with irrigation. It died in the ground in my home garden. In zone 9a, it seems to require a little care to thrive.

Sedum spectabile (syn. Hylotelephium spectabile) struggles in the ground in my upper zone 9a garden. It grows well in a friend’s nursery with good potting soil and frequent irrigation.

Sedum tetractinum, the green penny sedum, is another plant found in local nurseries that requires regular irrigation. A plant in a shady, unirrigated part of my garden died soon.

It may not be wise to generalize, but it appears that the cold hardiest Mexican species may grow easily in the warmer parts of the Coastal Southeast. Many of the more familiar Sedum species that are common in local nurseries and in mail order catalogs are native to Europe. They seem to require more care. In particular, they seem to need regular irrigation in zone 9a.

This is a medium-sized genus of evergreen shrubs and trees native to Asia. One species is widely cultivated in warm climates for its edible fruit.

The rose family, Rosaceae, includes herbaceous plants, shrubs, trees and vines. It includes agricultural crops like Indian hawthorn (Raphiolepsis,) strawberry (Fragaria,) apple (Malus,) plum, cherry and apricot (Prunus,) pear (Pyrus,) and blackberry and raspberry (Rubus.) Ornamental plants include redtip (Photinia) and spiraea (Spiraea.)

bronze loquat

This is an evergreen tree that grows to a height of about twenty feet tall.  The bark is smooth and gray. New leaves are a distinctive bronze-red color. Large clusters of white flowers are produced in spring. The fruits are small and are reported to inedible. It requires a moist, well-drained soil, sun and good air circulation. It is reported to grow from zone 8b to 10.

This plant is available from specialty nurseries. It is propagated by seeds and cuttings.

I have not grown this plant yet. I have seen nice specimens in Savannah, Georgia and Charleston, South Carolina.

loquat, Japanese plum

This is a medium-sized, evergreen tree to about thirty feet tall. It has a thin, gray bark. It has spikes of small, fragrant white flowers in fall and winter. It produces edible, sweet, orange fruits in spring. It is drought tolerant and requires a well-drained soil. The plant is popular in the region’s gardens. It is reported to be moderately salt tolerant. This plant is recommended for zone 8 and south. Fruit flies are pests in the southern part of its range.

Loquat has escaped cultivation in southern and central Florida. When growing it for fruit production in the Coastal Southeast, it should be managed to control its spread.

This plant is available in local nurseries. They are grown from seed. Named cultivars are available in fruit tree catalogs. Usually, these plants are grafted. They may be propagated by air layers, also.

My plant produces new growth in mid- to late February to late March. The old leaves fall shortly afterwards. It flowers between August and December. In several years in my garden, freezes have killed the flowers or young fruits every year. Recently, I ordered a selection, ‘Gold Nugget,’ from a nursery in Georgia. This cultivar is supposed to produce flowers and fruits later in the spring. ‘Coppertone’ is a selection that has leaves with a copper-colored underside. Some suspect that it is a hybrid.

This is a large genus of shrubs, vines, and trees native to Africa, Asia, Europe, North America, and South America. Several species are native to the Coastal Southeast. Several species are decorative and the berries of the native species are a valuable food for birds and other animals. A few are cultivated in our region. Typically, they are found in acidic soils.

The family Ericaceae includes pipestem (Agarista,) heather (Erica and others,) mountain laurel (Kalmia,) doghobble (Leucothoe) and azalea (Rhododendron.)

sparkleberry, farkleberry 

This is a large deciduous shrub or small tree capable of growing to twenty feet tall or more. Unlike some of its relatives, it does not sucker. It has a large number of small, white, bell-shaped flowers in spring. Tiger and zebra swallowtail butterflies visit these flowers. Birds eat the small, black, berries although they are nearly tasteless to me. It grows naturally in the shady woodland understory in acid soils in well-drained sites. Various references recommend it for zones 6 or 7 to 9. 

This plant is available from nurseries specializing in native plants. It is an attractive flowering plant that should be used more in local landscapes. It is propagated by seeds and softwood cuttings.

My plants produce new leaves between late February and mid-March. It flowers in early April to mid-May. Fruits ripen in October and may persist until the flower open in spring.

highbush or rabbiteye blueberry 

This is a suckering, deciduous shrub to eight foot tall or more. Small tubular white to pink flowers appear in spring before the leaves. The sweet fruits vary from black to blue depending on the  waxy coating that produces the blue color. Some of the black-fruited wild plants have fruits that rival commercial cultivars for size and flavor. Many of the cultivated selections are hybrids whose parentage includes V. darrowii. Plants grow well in sun to part shade in moist, well-drained, acidic soils. It is recommended for zones 5 to 9. 

Commercial selections and hybrids are commonly available in local nurseries. I have not seen wild types for sale. Plants are propagated by softwood cuttings and digging of suckers.

My plants are naturally occuring natives and planted horticultural cultivars. Flowers open from mid-January to early April, depending on temperatures. They produce new leaves by mid-March. The ripe fruits ripen mid-May through July.

Darrow’s blueberry 

This is a semi-evergreen, suckering shrub with small, blue-green leaves. It grows three to four feet tall. Both the new growth and the flowers are pink. The small blue to black fruits are tasty. In nature, it is found in well-drained sites in sun or part shade. I see no references to its cold hardiness. It has a limited natural range in the southeast that includes zones 8b through 9. 

This plant can be found in native plant nurseries and specialty catalogs. It is propagated by seeds, softwood cuttings and digging of suckers.

My plants flower from early to late March. They produce new leaves in late March to early April. Foliage is reddish in winter. It is evergreen in my lower zone 8b garden.

This is a medium-sized genus of shrubs and trees native to Asia. They are rare in gardens in our region. 

The Lauraceae is a large plant family of woody plants, mostly evergreens. This family ranges around the world. It includes familiar plants such as cinnamon (Cinnamomum,) redbay and avocado (Persea) and sassafras (Sassafras.)

This is a medium-sized evergreen tree from China. One reference says it is capable of growing to sixty feet tall. The catalog said it has a conical form and is best in shade. Little information is available on the cultivation of Phoebe species. A report from Austin says it has survived temperatures below 11° F. It seems drought tolerant.

Phoebe species are rare, even in specialty catalogs. Plants may be grown from seeds. Cuttings and layers are possible but they are reported to be challenging.

My plant produces new leaves once each year in early to mid-April. It has grown slowly in a shady, unirrigated site in my upper zone 9a garden. It grew eight feet tall in eight years, surviving summer-long droughts and winter lows in the upper teens F.

This is a large genus of herbaceous and woody plants from warm climates around the world, mostly in Africa and Madagascar. A few species are native to the Coastal Southeast and several weedy species have become established here, mostly in disturbed sites. Some, at least, are food plants for bella moth larvae.

The bean family, Fabaceae, is one of the largest of the plant families. It is characterized by seed pods that are known to botanists as legumes. This is a large family that includes many important economic crop genera, including peanut (Arachis,) soybean (Glycine,) alfalfa (Medicago) and beans (Phaseolus.) Ornamental garden plants include orchid tree (Bauhinia,) redbud (Cercis,) coral tree (Erythrina,) lupine (Lupinus) and black locust (Robinia.)

Cape rattlebox

This is an evergreen to deciduous shrub to small tree to about 10 feet tall. It bears bright yellow flowers through the growing season with strongest flushes in spring and fall. It is reported to grow in moist soils in South Africa but I consider it to be somewhat drought tolerant in northeast Florida. It grows best in full sun, or a bright partly shaded spot. It is reported to be cold hardy from zone 8 to 10. From my experience, it is reliably cold hardy in middle zone 9a.

Because so many of its relatives are weedy, plant any exotic Crotalaria with some caution. This species has grown slowly and has not set fruits in my unirrigated, zone 9a garden but it might behave differently in a different site or in a warmer zone.

This plant is rare in cultivation. It might be found in specialty catalogs. Propagation is by seeds and summer softwood cuttings.

In my garden, new growth starts in mid-March. Scattered flowers appear through the year. Heaviest flowering starts in late March, usually with another flush starting around late September. My plants are deciduous when winter temperatures drop into the mid-20’s F. Small branches may be killed by temperatures in the low 20’s F. The plant in my northernmost zone 9a garden died after two successive winters with temperatures in the upper teens F.

This is a native annual with stems that spread over the ground and reach only a couple of inches tall. Small but bright yellow flowers stand on short stalks above the foliage. Small, inflated seed pods up to an inch in length follow the flowers. In the wild, it grows in sunny, reasonably well-drained sites, often in poor soils. It will not compete with a healthy turf but can invade sparse lawns. Reportedly, it is cultivated in gardens but I find little cultivation information. Range maps show it growing on the eastern coast from approximately zone 6b south into tropical Central America.

I have not seen this plant in local nurseries. Plants can be propagated by seeds. It should be encouraged and enjoyed where it grows naturally.

My plants are naturally occurring natives. The earliest flowers appear in late March. They die back with the first hard freeze. It is a host for the brightly-colored bella moth. This is a white to tan-colored moth with orange and black markings on its forewings and bright pink to orange hind wings. I see this moth throughout the summer and fall when I walk across the lawn and cause them to fly up. I find bella moth larvae on two other legume genera, Baptisia and Sophora.

A few native and several exotic (non-native) species of Crotalaria may be found in the Coastal Southeast. Some, like the showy rattlebox or Crotalaria spectabilis, are regarded as noxious weeds throughout their range in the United States. This annual weed prefers open, sunny sites and is found in disturbed areas, pastures, roadsides and open pine forests. I do not know how long these seeds can survive in the soil. Like some other members of this family, the seeds can remain viable in the soil for several years. I have been pulling seedlings from some sites for five years, so far. Each  year, fewer seedlings appear.

Another common weedy species in much of the Coastal Southeast is Crotalaria lanceolata. It is a much smaller plant than Crotalaria spectabilis but the plant is more difficult to spot in a pasture and I have seen much larger numbers of this species within a given area. Persistent removal of this plant yielded good results. The number of seedlings has dropped rapidly each year over five years.

This is a large genus of herbaceous plants ranging over warm and cool climates of Africa, Asia, Australia, Europe, North America, and South America. Some effort has gone into hybridizing garden plants from this genus but they are rarely found in local nurseries or landscapes.

The aster family, Asteraceae, is a huge genus of herbaceous and woody plants that is found around the world. Only the orchid family rivals the number of species in this family. They may be annuals, herbaceous perennials, shrubs, trees or vines. Important members of the family include tickseed (Coreopsis,) blanket flower (Gaillardia,) sunflower (Helianthus,) goldenrod (Solidago,) marigold (Tagetes,) ironweed (Vernonia) and zinnia (Zinnia.)

Spanish needle

This is a native annual or herbaceous perennial (depending on the winter low temperature) to three feet tall or more. Small white daisies with yellow disks can be produced throughout the year, flowering heaviest in late summer and fall. It grows in sun or part shade, in any reasonably well-drained soil. They are drought tolerant once established. Flowers are attractive to butterflies. This plant should be used in naturalistic or wildlife gardens but it has two habits that make it undesirable for formal gardens. The seeds stick to clothing and pets’ fur, and the plant is fast growing and difficult to pull. It ranges naturally across most of the Coastal Southeast. According to the USDA, it is absent from Texas and Mississippi.

The scientific name of this plant is thoroughly confused with Bidens pilosa in popular literature. This plant has been lumped under the name B. pilosa in the past and some botanists today continue to lump them together. A 1986 article by Robert Ballard in the American Journal of Botany describes the separation of these species and the differences between them. Bidens pilosa seeds have three to five barbs and B. alba has two or none. Remember that daisies have sterile ray flowers that look like petals. These ray flowers are absent or about an eighth of an inch long in B. pilosa while the ray flower of B. alba is one quarter to over one half inch long. Bidens pilosa is reported to be an annual, even in warm climates. 

Bidens alba is not available in nurseries. Plants are grown easily by seeds and summer stem cuttings.

Plants in my zone 9a gardens are naturally occurring natives. They are perennial some years and flower from late spring to the first hard freeze. A winter low in the upper teens killed plants in the open. Volunteer seedlings replace lost plants in the following spring. I encourage this plant in certain sites in my home garden and at the University of North Florida but I work to control it in the more formal  garden areas.

Spanish needle

This plant is native to much of the southern United States, ranging from California to Massachusetts. It differs from Bidens alba in having a doubly divided leaf. The daisies tend to have only a few ray flowers which may be yellow or white. This plant attracts butterflies and other pollinators but tends to be weedy and has the seeds that stick to clothing like B. alba. It may be most appropriate for naturalistic gardens and natural areas. 

Selections of Bidens ferulifolia are cultivated in gardens. It is native to the American Southwest and Mexico. They are drought tolerant, creeping plants. I have not tried this species, yet.

Some yellow-flowered species grow naturally in the Coastal Southeast. The ones I know are annuals that grow in moist or swampy conditions. Bidens laevis has smooth, simple leaves. It flowers in fall. Bidens mitis has compound leaves with deeply dissected leaflets. It flowers in fall, also, at about the same time as B. laevis. 

I have not seen these plants for sale. They should be encouraged and enjoyed wherever they grow naturally. They may be propagated by seeds.

This is a large genus of herbaceous perennials and shrubs, mostly from cool climates of Africa, Asia, Europe, North America and South America. I have not explored this genus thoroughly. At least a few ornamental species are sufficiently heat and humidity tolerant to thrive in the Coastal Southeast. Some of the gray-leafed Artemisia species are known by the common name of dusty miller. Jacobaea maritima is another common garden plant that is known as dusty miller

The aster family, Asteraceae, is a huge family of herbaceous and woody plants that is found around the world. Only the orchid family rivals the number of the Asteraceae. They may be annuals, herbaceous perennials, shrubs, trees or vines. Important members of the family include tickseed (Coreopsis,) blanket flower (Gaillardia,) sunflower (Helianthus,) goldenrod (Solidago,) marigold (Tagetes,) ironweed (Vernonia) and zinnia (Zinnia.)

Limelight wormwood  

This is a stoloniferous, herbaceous perennial to about six to twelve inches tall. The stems die back to the ground but leaves at the surface remain evergreen, usually. This variegated variety is grown mainly for its foliage and the two to three foot tall flower spikes may be removed as they develop in late summer. It is at its best as a somewhat aggressive groundcover with room to spread. Because of its rapid growth rate, it is not a good plant for a small, formal garden. It grows well in sun to part shade, in a moist, well-drained soil. References state that it grows from zone 4 to 8 but it has proven itself to be vigorous in northern zone 9a.

This plant is available in local nurseries. Propagate by summer cuttings or division.

Plants in my zone 9a gardens spread rapidly where irrigated but struggle to survive in drier sites. They die down with the first freeze. They resprout in late winter.

Powis Castle dusty miller 

This is an evergreen herbaceous perennial that grows to two to three feet tall and several feet wide. It is reported to be a hybrid between A. arborescens and A. absinthium. It has a beautiful, deeply dissected, silver-gray foliage. It is best in a sunny site, in a reasonably moist, well-drained soil. I found it listed as a salt tolerant plant by one site. Various references give a wide range of hardiness information. It is reported to be reliably cold hardy from zone 6 to 9, possibly into zone 5.

This plant was popular for a while but seem to have disappeared from local nurseries. It is available in mail order catalogs. Propagate by summer cuttings.

My plants struggled and died in zone 9a before I realized that they are not drought tolerant enough for prolonged summer droughts in the sandy soil of my home garden. This plant grows very well in a container of good potting soil with regular irrigation but remains a short-lived perennial that tends to die out in its second summer.

This is a medium-sized genus of shrubs and trees native to warm areas of North America and South America. These colorful flowering trees are cultivated in warm regions around the world. At least, three species grow as far north as zone 9a in the Coastal Southeast. The genus Handroanthus was separated from the genus Tabebuia on the basis of DNA studies. One reference states that the species of Handroanthus have hairs on the surfaces of their leaves while Tabebuia leaves are smooth. 

The Bignoniaceae family contains shrubs, vines and trees that range around the world. It includes cross vine (Bignonia,) trumpet creeper (Campsis,) catalpa (Catalpa,) jacaranda (Jacaranda) and yellow elder (Tecoma.)

golden trumpet tree

This is a small tree to about twenty-five feet tall. Compared to the other yellow-flowered species in our area, H. umbellatus, this tree is a little taller, has deeper yellow flowers and has rusty-red hairs on its new flower buds and leaves. It grows well in a well-drained site in sun. Reportedly, it has some salt tolerance. This species has not been trialed for long in upper zone 9a. It may benefit from a some protection from cold winter winds.

This plant is available in central Florida nurseries. It is propagated by seeds and semi-hardwood cuttings.

This plant struggled and died in my northern zone 9a garden. It survived a winter low in the mid-20’s at the University of North Florida (middle zone 9a) and flowered the following spring. Typically, it flowers in February.

 ipe, pink trumpet tree 

This is a medium-sized tree to about twenty-five feet tall. It is deciduous for a short time in spring when the large, trumpet-shaped, pink flowers appear. Its leaflets are lightly fuzzy and have small teeth along the margins. It grows best in a sunny, well-drained site with some protection from winter winds. 

This plant is available in central Florida nurseries but is difficult to find further north. It is propagated by seeds and semi-hardwood cuttings.

The young plant in my northern zone 9a garden has experienced three winters with lows in the upper teens in the past ten years. After a decade, this scrawny, little survivor is nothing more than a curiosity. A few miles south, plants at the Jacksonville Zoo and the University of North Florida have grown to tree size. They tolerate winter lows in the low to mid-20’s F without difficulty. They flower in late March to mid-April depending on the spring temperatures. It seems to have moderate salt tolerance. 

yellow trumpet tree

This is a small tree to about twenty feet tall. It drops its leaves in spring just before it is covered with bright yellow, trumpet-shaped flowers. Its leaves are smooth with entire margins. It grows best in a sunny, well-drained site with some cold protection.

This plant is uncommon in central Florida nurseries, and almost unknown further north.  It can be grown easily from seeds. Reportedly, it is propagated, also, by air-layers.

A plant struggled for a few years in my upper zone 9a garden before dying. Plants grow slowly but well in UNF’s middle zone 9a landscape. Matt Encinosa says that in middle zone 9a, his plant flowers in late February to mid-April depending on the spring temperatures.  New leaves appear in shortly after flowering.

hybrid trumpet tree 

This is a relatively new hybrid that should grow to about twenty-five feet tall. The plant in the image is the result of a cross that Matt Encinosa and I made between two of the cold hardiest species, H. impetiginosus and H. umbellatus. Our plant has the habit and vigor of H. impetiginosus but the flowers open yellow before fading to pink. Its leaves are glossy with a serrated margin. The new leaves of this particular plant are dark burgundy in color (see photo below.)

This cross has been made by a few people around Florida and can be found in a few central Florida nurseries. This hybrid should be propagated by semi-hardwood cuttings or layers.

My plant has grown for four years in a sunny, well-drained site in middle zone 9a. It survives winter lows of 25 degrees F with no apparent damage.