13.9.19

Living on the Edge: the Cottontop Cactus



image by Zdenek Richter

The Cottontop Cactus, Echinocactus polycephalus, is a moderate-sized barrel cactus that lives in some of the driest areas of North America. There are two similar subspecies: polycephalus, the most widespread, found in parts of California, Nevada, Utah, Arizona and northern Mexico, and xeranthemoides, found near the Grand Canyon in southeastern Nevada and Northern Arizona. “Way over to Hell and gone” is an apt description of the species’ habitat. It occurs from the spectacularly desolate mountains overlooking Death Valley to the wretchedly arid flats of the Cabeza Prieta National Wildlife Refuge.
  
Cottontop Cactus grow in arid or hyper-arid landscapes that usually receive no more than 5 inches of precipitation per year. In the Mojave Desert the species must survive exclusively on winter rainfall, but plants in the Sonoran Desert occasionally experience summer thunderstorms during the monsoon season. In the stony wastes in which they grow, the sparse rains quickly drain away or evaporate in the heat.

The barrels grow to about 2 feet or so, gradually branching from the base to form clumps of up to 50 heads. Thick, fierce spines give the heads the appearance of medieval weapons. Rainfall temporarily turns the spines brilliant red. Given the slow rate of growth, it’s thought that large plants are over 100 years old. New growth tends to occur in Spring, months after the Winter rains have ended, and flowering takes place during the scorching heat of Summer.

The ripening fruit is embedded in a dense mass of tough, white fiber, thus the name "Cottontop".


image by Michael Thomas Bogen

Packrats and other rodents have to chew through the protective spines and fiber to get to the fruit.

Seeds found in ancient packrat middens indicate that the species has been dancing around its current range for the past 30,000 years. Favorable conditions for seed germination are infrequent occurrences, and seedling growth is very slow. With increasing temperatures and the long term prognosis of climatological drying of the Southwest, the survival of this tough, tough species in its exquisite environmental niche is, unfortunately, in question. 
image by Michael Thomas Bogen




 

27.8.19

Bananaquits in our Gardens



Image by Matt Magillivray
Recently, a pair of modestly colored, unusual birds have moved into the entrance area at Pinecrest Gardens. Occasionally found in South Florida, they most likely have flown here from the Bahamas. They are quite noticeable, actively flitting from shrub to signpost to roofline to trees. Their frequent singing is loud and pleasant; we hope that they stay and perhaps nest here.                                                         

The Bananquit, Coereba flaveola, is a small bird of the New World tropics. The species belongs to the large avian group known as perching birds, a taxonomic order that includes many of the best known and liked songbirds, including their close relatives, the Tanagers. Bananaquits are small and mostly grey, with white or bright yellow breasts and white-striped heads. They are inhabit a wide geographical range that includes much of the South American tropics and subtropics east of the Andes Mountains, parts of Central America and Mexico, and Caribbean and Antillean islands. They live in diverse habitats, including open forests and scrub, and also live and nest in gardens in urban areas.

Bananaquits consume some insects. Mostly, they use their slender, down-curved bills to pierce flowers for their nectar and eat sweet fruit, their primary foods. Although it is a poor food source, people often use granulated sugar or syrup to attract them to bird feeders. They are bold creatures that seem comfortable around human noise and activity.

Like so many other organisms, there are unanswered mysteries about the birds. One question concerns their distribution: why are Bananaquits only found in some places, but not others, e.g. Cuba, that would seem to have suitable habitat? How often do they occur in Florida? What accounts for the great variability in the physical appearance of different populations? Off the Venezuelan coast and on some other islands, for example, the birds are nearly entirely black. It seems that what biologists classified as a single species might actually be several different birds!
 
To hear a Bananaquit singing, open this YouTube video: https://www.youtube.com/watch?v=_bSyGaAO9fY



22.8.19

Olive Trees in South Florida! Hold On, You’re Getting Excited for the Wrong Reason


 

 
Talk of olive trees in South Florida and people tend to think of the Black Olive, Terminalia buceras, a tree in the family Combretaceae, the White Mangrove family. Naturally found in the Caribbean, Central America, and Northern South America, there is some public confusion over its identity as the cultivated edible olive species. It ain’t. It’s doubtlessly called Black Olive due to the similiarity in the appearance and staining properties of the ripe fruit.

To see a real olive tree, visit Pinecrest Gardens, where a 125 year old specimen has been planted in one of the dry garden areas. With its silvery leaves and thick, gnarled trunk, it looks just like the individuals that one might encounter on a Greek island, the Andalusian countryside, or a Lebanese mountain.
Olive at Pinecrest Gardens
The Common Olive, or just plain Olive, Olea europaea var. europaea, is a tree that originated in the Mediterranean Basin region. It’s one of many members of the family Oleaceae, the Olive family, but the only species that is widely grown for its fruit. The Olive is an ancient cultivated crop that was domesticated from the wild Oleaster, Olea europaea var. sylvestris, about 6000 years ago; the earliest evidence of olive use is 19,000 years ago from an archeological site in Northern Israel. To be edible, olive fruit must be fermented (pickled) by allowing the natural bacterial community found on their skins to grow, or by processing them with lye.
Old Olives near Chalkio, Greece
Olives are mostly grown for oil production. Established groves having productive trees are often hundreds of years old. The species also has fine, durable wood that is rot-resistant and excellent for carving.
Olives develop heavily gnarled trunks 
Olives were brought to the New World by the Spanish. In Florida, olives were planted at St. Augustine and New Smyrna Beach. Currently, the University of Florida is encouraging commercial planting in the central and northern parts of the state, where cooler winters make fruiting possible. Olives do best in Mediterranean-type climates, where Winters are mild and moist and Summers are long, hot, and dry. They are an adaptable species but require full sun, perfect drainage, and no irrigation once established.   
 

15.8.19

Ah, the Romance, the Exoticism, the Colonialism, the Breadfruit!


 
Image by Ryderfoot
Breadfruit, Artocarpus altilis, is a strictly tropical-growing tree in the same family that includes figs, mulberries, and Jackfruit, the Moraceae. It’s a fairly large, big-leaved tree that bears a starchy edible fruit. Originating in New Guinea and the Philippines, its wild ancestor was spread throughout the Pacific during the times of the great Austronesian and Polynesian ocean voyages, starting 3000 years ago. Breadnut, Artocarpus camansi, is still cultivated, especially in New Guinea for its edible seeds. The domesticated breadfruit is mostly seedless. The unripe fruit is eaten after being boiled, baked, roasted, or fried. It tastes somewhat like potato or bread. It's quite popular across Polynesia and many countries around the world where it is cultivated.  
 
Breadfruit is also an example of botanical imperialism, as depicted in Mutiny on the Bounty. Young plants were transported by the British to the New World, providing an easily grown, calorie rich food for slaves working on the island colonies.

Image by Pxleyes
Breadfruit is quite adaptable in cultivation, but prefers rich, well drained soils in areas with high rainfall. It’s strictly tropical in its temperature requirements and won’t tolerate any but the mildest of cool weather. In some places it has escaped to the wild and has become a bit of an invasive pest.


Image by NTBG

Breadfruit is a very attractive landscaping tree. Its large, deeply incised leaves make a decidedly tropical statement. In the past, Breadfruit was nearly impossible to cultivate long-term in South Florida except in the most protected of locations. With increasing temperatures and mild winters, chances have greatly improved for success in warm locations near the coast. 
   
 

31.7.19

Sealing Wax Palms, Species Conservation, and Environmental Change



photo by David J.Stang

The Red Sealing Wax Palm, Cyrtostachys renda, is a slender, medium-sized clustering palm with pinnate (feather-shaped) leaves found in tropical peat swamp forests in Southern Thailand, Peninsular Malaysia, Sumatra, and Borneo. Of unique and striking appearance, the species is widely grown in the world’s tropical regions.

  
And what an appearance!  One of the world’s most beautiful palms, the tree’s graceful, thin, green-ringed trunks support dazzlingly red or orange crownshafts and colorful feathery leaves.  Outside of the tropics, it’s considered a “holy grail” plant for gardeners; a palm that is both difficult to find, to accommodate, and to grow in a non-greenhouse setting. If you’ve ever visited a public garden or park in the tropics or a large conservatory in more temperate zones, the species can frequently be found planted en masse or prominently displayed as a specimen. The Sealing Wax Palm is commonly used as a landscape tree in wet tropical climates.

Having so much horticultural value, many plants have been removed from the wild. The International Union for the Conservation of Nature (IUCN) listed the species as threatened in 1995, thus motivating Indonesia to pass protective legislation. Cyrtostachys renda was no longer considered at risk by the IUCN in 2000. 
Cyrtostachys renda in habitat
 Unfortunately, IUCN listing or delisting often does not predict an organism’s survivability in the current age of rapidly increasing environmental stress. It’s not possible to assess the conservation status of all of the world’s species; many thousands are undescribed and doubtlessly pass from the biological stage without our ever knowing of them. Assessments are based upon field surveys that can only give a snapshot of a species’ populational health and abundance. In some instances, all it takes is a forest to be logged out, cut, or burned for agricultural conversion, drainage of a marsh for construction of a new housing project, the local loss of a specific pollinator, or sustained harvesting or poaching to result in a species’ extinction. Of course, underlying most environmental stressors is the big one that “rules them all”: climate change inevitably disrupts the subtle and complex phenology of entire biological communities. It’s difficult to ascertain just how stable wild Sealing Wax Palm populations really are. It should be assumed that since the species’ habitat is highly threatened, especially by conversion to Oil Palm plantations, then the palm probably is, too.

Forest clearance and road construction for Oil Palm cultivation




An "island" of forest remnant




Miles of Oil Palm monoculture





Primary forest
 
The peatlands or peat swamp forests are highly threatened ecoregions in Southeast Asia. They function as huge carbon sinks, holding the accumulation of thousands of years of plant growth. Dead plants don’t break down easily in the water-laden, oxygen deficient ground, and the carbon in their bodies remains naturally stored as peat. Peatlands are ancient, biodiverse, and store more carbon than other types of tropical forests, including the better-known rainforests. When they are drained and set ablaze for clearing, immense amounts of carbon dioxide are released into the atmosphere, adding to global warming.


Peat forest burning


Fire-induced air pollution












 

5.10.18

Cycads: Life in the Slow Lane


 



Gardening is an endeavor that can teach us many things about life. Surely one of the obvious lessons is patience: patience to make garden designs become a reality, patience to nurture plants and watch them thrive. Patience is needed when setbacks occur from pests or disease or truly damaging weather events like cold snaps or hurricanes. Unless our gardens are composed of annuals that quickly cycle through blooming and replacement, we learn patience from watching our plants grow in time into beautiful specimens.

 

Cycads, seed-bearing plants that are frequently mistaken for palms or ferns, are perhaps the ultimate slowpokes in our gardens. They are members of three very closely related families whose nearest relatives are conifers, such as pines, and the Ginkgo, an ancient tree species widely planted in northern landscapes. In books and films, cycads are popularly portrayed as primitive plants that were grazed upon by dinosaurs. The origins of the cycads reach far back in geologic time to the dinosaur period and beyond, but the origins of present-day species are much more recent. Today, cycads are considered relic survivors found in the New World, Africa, Asia, and Australia. Some cycad species are amongst the rarest of plants, with populations that are scattered and highly localized, sometimes to a single hill or mountain. Nevertheless, within their native ranges, certain cycad populations can number in the hundreds of thousands or even millions of individuals. 



Cycads are magnificent garden plants that live on a timescale that can humble us short-lived humans. They often grow slowly, take a while to reach maturity, and have lifespans that can stretch through centuries. Unfortunately, many cycad species numbers are dwindling or threatened with extinction. Human-caused habitat alteration and loss are the great dangers posed to their survival. Changing climate that increases the occurrences of drought and intense fires also plays a part. Due to rarity, slow maturation, and difficulties in propagation, certain species have come under intense illegal collecting pressure, pushing them to the point of disappearance in the wild. Ongoing Cycad conservation efforts focus on research and increasing both the numbers and sustainability of wild populations. An additional benefit of all this attention is that valuable horticultural knowledge has become available to gardeners who are interested in growing cycads.


The fascinating reproductive strategies of cycads could easily be the subject of a dedicated lengthy blog post. Cycads bear cones on separate male and female plants; sometimes odors and heat are generated within the cones  to attract specific insect pollinators, required to produce viable seeds. When habitat pressures eliminate wild pollinators, or when the number of adult plants of reproductive age falls below a certain density to maintain pollinator populations, the cycad population can become functionally extinct. If the unfortunate species is only found in a single location, it's game over. In cultivation, however, male pollen can be stored and female cones can be hand pollinated. Some cycads produce offsets that can be detached and rooted to produce more plants.  

 

Probably the best known cycad is the Sago, Cycas revoluta, originating in Southern Japan and its offshore islands, but now popular worldwide, even as a houseplant.  Many desirable cycads originate in South Africa, growing in places that are drier and have lower humidity than Florida. There are still many species, however,  that do well in South Florida. Some make superb xeriscape specimens, while others will thrive in irrigated garden settings. Of course, many cycads from Summer- rainfall regions of Africa and Asia as well as from areas of Mexico, Central and South America and Australia are suited to South Florida gardens. Our state even has its own native cycad, Coontie, a quite adaptable species.

 
A severe threat to the numerous species in the genus Cycas is the Aulacaspis Scale, Aulacaspis yatsumatsui. originally native to Southeastern Asia. The insect has been inadvertently introduced into various locations around the world, where it has no natural predators. In Guam and other Western Pacific islands it has virtually eliminated the native Cycas micronesica. It is a serious horticultural pest in Florida, where its presence has essentially ended the cultivation of Cycas without constant vigilance and treatment of infested plants. 

 

13.8.18

The Desert Rose




Gardeners in South Florida are succulent-adverse. Some seem to think that all succulents come from deserts and won't grow here, or have undesirable spines, or are basically uninteresting. We are attracted to flashy colors and often don't understand or appreciate the forms and survival strategies of the plants that we grow. Consequently, nurseries and home centers meet the lack of demand by offering few succulents, so the feedback loop continues. In fact, many succulents are well suited to our seasonally dry climate and fast-draining soils. They can have extremely showy flowers, great color, and striking forms. Above all, the survival strategies of succulents are some of the most amazing of any plants.







An interesting genus of Old World succulents, Adenium, is popularly known as Desert Rose. Unlike true roses, adeniums are thornless. Adeniums can be found from the Arabian Peninsula to Southern Africa, as well as the floristically fascinating island of Socotra. The genus is part of the larger Apocynaceae family that includes Plumeria or Frangipani. Indeed, the relationship between Desert Roses and Frangipani is easily seen in the similarity of their flowers. Like Frangipani, Adeniums are the subjects of intensive selection and breeding programs to produce all sorts of horticultural cultivars. Flower color, patterns, and size have been greatly modified from the wild ancestors, often resulting in additional secondary changes to the overall form of the plants.



 

Adenium obesum is the most widespread species of the genus. In the past, its many geographic forms have generated much taxonomic confusion. Previous assigned species names such as arabicum and somalense have all been subsumed within obesum, despite the morphological differences. Local forms of the species can be found in Kenya, Somalia, Saudi Arabia, Yemen, and Oman. Some are small shrubs, others large, and others tend to grow as small trees. No matter the shape, all have similar horticultural needs. All Adenium obesum will thrive in South Florida. 





Grow adeniums outdoors in full sun, in very well drained soil. Adding some none-limestone rough gravel, such as lava rock or expanded shale to the mix is a good idea. Coarse silica or granite sand also helps with drainage without raising the soil alkalinity to an unacceptable level. Adeniums tend to be quite frost sensitive, so preventing them from turning to mush on the coldest South Florida nights will require some protection. They are great in pots, especially those made of terra-cotta that offer quick evaporation and gas exchange for their roots. Use a very porous mix that incorporates much perlite and/or gravel to speed drainage. If the wet potting mix won’t hold together when squeezed in the hand, it’s the correct porosity. Whether planted or potted, mulching adeniums with gravel is a natural and very attractive way of displaying them. Give them a slow or controlled-release fertilizer that contains some microelements and is fairly low in nitrogen, such as 8-2-12. Even 10-10-10 or 7-7-7- will work, as long as the nitrogen isn’t too quickly available for the plants. Water these heat and light loving plants regularly during their active summer growing period. To prevent rot, they must be allowed to dry out completely between watering.





Adeniums tend to go semi-dormant in the winter, losing most or all of their leaves. They don’t need much water during those times, but also don’t appreciate being completely bone dry for months on end. They like an occasional soaking drink, as long as they can dry quickly. Even though the plants might be leafless, they are still actively using sunlight. Lightly scratch a Desert Rose’s silvery-grey stem. Underneath is a thin green layer that continues the job of photosynthesis, even without the presence of leaves.





Horticultural varieties of Desert Roses, especially grafted plants, don’t always produce the same thickening at their base (caudex) that wild forms are famous for. Some greatly resemble their frangipani relatives by not thickening at all. To produce a thick base for display, gradually remove some soil and raise the level of the plant in its pot or replant it in its bed with a portion of its roots exposed. Doing so will not cause harm, as long as any freshly severed roots are kept dry to prevent rot.













18.11.16

The Great Wheel's Turning

 
 

Nature deficit disorder is a term used to identify the various negative symptoms of human alienation from the natural world. Like many other conditions, its most profound effects are manifested in children. The malady has been well studied, although not considered a formal medical diagnosis, and is generally accepted in describing the world's highly urbanized societies.

image credit: Morphocode 
By 2009, greater than 50% of humankind were living in cities. For the first time in history, most people were cut off from the intimate environmental associations that are fostered by growing food, hunting and fishing, and living closely with inevitable Nature. It is estimated that three out of every four people will be urban dwellers by 2050, with many of us living in megacities of over 10 million. 
  
I lived in Montana's second largest city 15 years ago. Comfortably small, it had about as many people as Coral Gables. The whole state's population was the equivalent of Jacksonville, in a place more than twice the size of Florida. Awareness of the natural world came with the territory, just by being there. Environmental issues, often contentiously debated, tended to be front and center in every day's news. Outdoor recreation was just what folks did. Anyone who identified themselves as Montanans, no matter their background, felt an intimate connection to the land, all of the inhabitants thereof, the weather of the Northern Rockies, and of course, the Big Sky.

image credit: Patrick Rasenberg
Like historical Montana, South Florida is a place of recent immigrants. We aren't that far removed from the region's frontier days. By the beginning of the last century the Indian Wars were finished. Both places had experienced their own terrible conflicts. Montana and South Florida were sparsely populated frontiers, similar to what other parts of the country had been like decades earlier; life felt a bit unsettled and raw. In South Florida, the construction of a large network of drainage canals would forever change the region. The original coontie harvesters, small farmers, shipwreck salvagers, Bahamian laborers and craftspeople, and the business dreamers would find nothing recognizable in today's urbanization, hydrological disruption, and profound environmental alteration. Even the beach sand has been pumped up from somewhere else. Successive waves of newcomers have brought their own expectations, based upon memories of the places that they come from and their expectations of what should be.

image credit: Frank Mirbach

Even in their diminished condition, our imperiled natural remnants are deeply moving. They demonstrate that the world functions with or despite us. Beyond providing free essential environmental services and economic benefits, beyond being the great wheel upon which our very lives depend, they lift our spirits and nourish our souls.


Few places in the U.S. can surpass South Florida in biological richness. Unfortunately, there's scarcely a region in this country that is more environmentally threatened. Many residents lack interest in much beyond the human manipulated landscape; environmental awareness seems nearly nonexistent.

The old Florida joke about there being only two local seasons, hot and hotter, is an unwitting commentary on how the glorious subtleties of the natural year are often ignored. We all should try to get out to the Everglades or Big Cypress and appreciate the annual dry down after Summer's tropical rains. Show it to your children. At this time of year, even in town, one notices the abundance of migrant warblers in the shrubs and trees and the raptors in the sky. If the weather turns cold, the manatees will move inshore and up the canals. Who can miss creatures the size of small cars? Very soon, the fine leaves on the bald cypresses will turn a rich russet color and fall, as the trees prepare for our brief, subtropical Winter. Take heart, just a few weeks later, the soft fuzz of leaves will reappear, clothing rough branches with the first golden-green sign of Spring.

 







            




29.10.15

A Blog About a Blog


Colvillea racemosa
courtesy of Richard Lyons' Nursery, Miami, Florida
flowering near Halloween

Recently, the question arose about how I write a blog about so many different topics ( over 200), and what initiates and sparks the information needed to write such a blog. I choose to write about topics with currency or education. Rather than write of anything that pops into mind, I select the topics primarily based on something tactical or current here at Pinecrest Gardens. The recent flowering cycle of our venerated Talipot Palm is a good example, or the Spring flowering of our Baker's Cassia trees and so on. In some instances, if I visit another garden, inspiration strikes me when I see a great tree or palm or flowering plant, worth promoting to the readers respective to the season. My hope is that a few readers will start to ask for the more unusual plants, learn a few new tactics, reconnect with their plants and gardens, and maybe enjoy their plants once again, not treat them as chores.  






Chorisia speciosa
flowering now in Miami


My overall idea is to promote plant diversity and promulgate some skills needed to make the plants grow well, most are based on personal experiences. In the most general sense, I try to show readers that there is a stunning and nearly endless spectrum of plants from which to choose. Further, there are myriad ways to grow plants. Many techniques are well known, but only to an older generation, lost to the newer generations, other than reading (perhaps on a blog) on the internet how gardening should be done. The tactile connections between gardeners, learned skills, and long term plant growth are definitely on the wane; replaced by cheap "disposable" plants with replacement guarantees from big-box stores.


Lagerstroemia speciosa
Queen's Crepe Myrtle- flowering now in Miami
courtesy of Richard Lyons' Nursery, Miami, Florida


Unquestionably and irrevocably, I am a plant addict. One wise friend summed it up rather starkly, albeit correctly: 'You'd live out of your vehicle, if your plants were well tended.' I try to pass on the skills I acquired over the last 4 decades. Often baffled by how little people know of their gardens and landscapes, I try to show off something new or revisit a heritage technique.  In the monthly workshops at Pinecrest Gardens, I often ask the question "what happened to people who tended to their gardens every weekend ?" The most frequent answer was surprising: "we have a landscape company do that now". The advent of disposable plants, inexpensive landscape services, and the digital age have moved gardening for food and pleasure and aesthetics to a darker section of our pastimes. There are so many wonderful plant and design options, so much good information available from experienced gardeners, and so much to be derived from growing your own plants with your own skills. I lament the war-cry of "Google it....", and prefer the idea of "try it yourself".

One favorite expression among the horticulturists I know is that 'plants are illiterate, and didn't read the book that said that plant was difficult to grow...' I suggest people try 'real' gardening, and perhaps see that even a well-tended container garden on  a balcony or patio deck has real benefits, if you take the time to allow yourself to enjoy it.....



Pinecrest Gardens