Category Archives: Climate

Agave colorata and its Blooming Attempt in ’18

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Agave colorata before flowering initiation, growing nearly horizontal, with a broadly cupped lower leaf holding water. From the Irish’s book, “Agaves, Yuccas and Related Plants”, “The leaves are 5-7″ wide and 10″-23” long [mine were all at the small end of this range] They are ovate ending in a sharp tip….The leaves are a glaucous blue-gray and quite rough to the touch. The margin is fanciful with strong undulations and large prominent teats of various sizes and shapes. A very strong bud imprint marks the leaves, which usually are crossbanded, often with a pink cast [not mine], and end in a brown spine 1-2 in. long.

This is one of the first Agaves I ever grew. Pictures on line of its rosette first caught my
interest, their leaf color, substance and sculptural qualities, the margins of its broad, thick leaves, with their rhythmic rounded ripples, each tipped with a prominent ‘teat’ and spine. This is not a large plant, typically growing 23″- 47″ in diameter and my plan was always to keep it in a pot as it is from coastal areas of the Mexican state of Sonora, found sporadically in a narrow ‘band’ south into Sinaloa.  Agave colorata is very rare and uncommon in nature and growing on steep slopes of the volcanic mountains in the coastal region in Sinaloan thornscrub. It often emerges from apparently solid rock cliffs sometimes clinging high above the water below.

Growing in Sonora and at Home

It is poorly adapted to our wet winter conditions though it is reputedly hardy into USDA zn 8, or as low as 10ºF.  Its natural northern limit is thought not due to cold, but by excessive aridity in the northern parts of Sonora.  I didn’t test it, leaving it outside under the porch roof, bringing it in when forecasts called for below 20ºF, as any plant is more susceptible to cold with its root zone subject to freezing. With perfect drainage and overhead protection, you might be able to get away with this in the ground, but the combination of significant wet with our cold is likely too much…still if someone wanted to try….At best I suspect this one would still suffer from fungal leaf diseases, disfiguring the foliage.

This is usually solitary, but it can be found occasionally in small clumps/colonies up to nearly 10′ across, pushing up against each other on their slowly growing and short ‘trunks’ to 4′ high.  My plant produced just a few pups over the first third of its life.

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I wanted to include a climate map of Mexico. This one utilizes the classic Koppen system designating the various climates based on temperature and precipitation and their seasonal patterns. Here it has been modified by Mexican climatologists to better reflect Mexico’s complicated geography…even so, because of the abrupt changes in elevation, and land forms, different climatic conditions can occur in close proximity to one another. Mountains can create wetter and drier areas that on a map of this scale are lost.

Sonora has three distinct geographic areas all running along a ‘line’ from the northwest toward the southeast, the Gulf of California and its associated coastal landscape paralleling the Sierra Madre Occidental, sandwiching plains and rolling hills in the middle.  The coast and plains/rolling hills are arid to semi-arid, desert and grasslands, while only the higher elevation of the easterly mountains receive enough rain to support more diverse and woody plant communities, scrub and Pine-Oak forests.

This map comes from the Arizona Sonoran Desert Museum. The link takes you to one of their pages which discusses the natural history of the desert, thornscrub and tropical deciduous forest of Sonora.

This region also varies north to south, the climate drying as you go north into the Sonoran Desert.  Moving south on down into Sinaloa, and further, is the some what wetter ‘dry deciduous forest’ biome with an array of woody leugumes, including several Acacia.  Agave colorata resides in the transition zone in between, in the portion of  ‘thornscrub’ near the Sonoran/Sinaloan border.  North and south the Thornscrub itself changes in composition.  The Sinaloan Thornscrub serves as a transition zone between the desert and the slightly wetter, taller growing, Tropical Deciduous Forest that continues the south.  All along this band running north on into Arizona’s Sonoran Desert are various columnar cactus a food source for Mexico’s migrating nectarivorous bat species.  It is a unique flora community, containing species from bordering floral regions and other species unique or endemic to this transition zone itself.  The area continues to be under threat, primarily by cattle ranching that moved into the region in the ’70’s and ’90’s bringing with it clearing and the introduction of non-native and invasive Bufflegrass, Pennisetum ciliare, also known under its syn. Cenchrus ciliaris, for pasture.  Bufflegrass is also a serious problem north into Arizona.  In Sonora many of the cleared woody species have since begun moving back in, while the smaller, more sensitive species have not.  Climate change promises to further squeeze it. (The World Wildlife Fund maintains a website with good descriptions of many eco-regions I sometimes find it very helpful when trying to understand the conditions of a plant I’m less familiar with.)

When growing plants like this, one should keep in mind the concept of heat zones.  The American Horticultural Society has created a map of the US delineating its ‘heat zones’.  It is based on the average number of days an area experiences temperatures over 86ºF.  At that temperature most plants begin to shut down their metabolic processes…they slow their growth.  Check out the AHS map (AHS US Heat Zones pdf.) and keep in mind that we are warming up!  The AHS map has us, Portland, OR, in zone 4, meaning we experience 14-30 days with highs over 86ºF each year.  Last summer, ’18, we actually had a record 31 days over 90ºF!  Now consider that the coastal/plains region of Sonora likely experiences between 180-210 such days!  Agave colorata may not need this, but it is certainly adapted to such a level of heat stress.  Something to think about, especially when you consider that we receive the bulk of our rain over the winter when our daily highs and lows average for Nov. 40º-53º, Dec. 35º-46º, Jan. 36º-47º, Feb. 36º-51º and Mar. 40º-57º…keeping in mind that we could freeze on most any of those dates.  The Sonoran Desert receives its minimal rainfall in a summer/monsoonal pattern….This is why bringing such ‘low desert’ plants to the Pacific Northwest can add another degree or two of difficulty to your success!

 

Growing this in a pot made perfect sense to me, but every decision carries consequences, not all of which I anticipated. Most Agave don’t form a ‘trunk’ growing its leaves, in a tight spiral, crowded along a very abbreviated stem, which adds little to its length to separate each consecutive leaf., but Agave colorata adds a little ‘extra’ slightly separating its leaves, resulting in a weak and kind of puny stem. If you’ve ever shuffled pots containing Agave more than a few years old, you understand that their crown, their substantial top growth, is relatively heavy, A. colorata is no exception, in fact their leaves each seem more substantial than leaves on many other similarly sized Agave. This results in a plant that as it grows begins to lean over, eventually, laying flat across the ground. As a Monocot the stems of Agave don’t caliper up over the years as does wood. These have no cambial meristem which would add secondary growth, and diameter, to the stem and as I said, with its relatively massive and heavy crown, it leans.  This is the same characteristic that gives their small colonies their height.

 

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On Ecology, Politics and Climate Change: the Links that Tear us Asunder

Warning!!! This is a rant! It’s political, economic, ecological and, most definitely, covers all of the connections between with climate change, these things and our future as a species.  I hope you choose to read it, but be forewarned!!

I woke up yesterday at 4:30am, unable to go back to sleep, so I got up and began writing this.  The state of the world, the absolute idiocy, meanness and short sightedness of politics today, the undeniable enormity of climate change and its inevitable impacts for every organism on the planet, drives me from paralyzing frustration, to near rage, to profound sadness and despair.  Most days all I can do is seek escape and I do this through gardening, reading eclectically, trying to follow some kind of routine, going for walks, a swim or a hike, sharing time with friends or delving into research on plants and the everyday miracles within them and their wondrously choreographed lives here on this planet….I spent my entire morning writing and rewriting this (and returned to it the following day, now today).  It is me ‘sharing’.  Yes, it’s a rant, it’s a bit of analysis, it’s a window into the world as I see it and it contains a hope I have…that I have to cling to most days, for this world and all that lives upon it, because what we have done, what we continue to do, is so profoundly destructive and disheartening to me. Continue reading

Puya: Growing These Well Armed South Americans in the Pacific Northwest

[I wrote this originally about 2 years ago as part of what turned out to be a too long look into the Bromeliad Family.  Here I present only the genus Puya spp. in an edited form with the addition of the species Puya berteroniana.  Go to the original article to read about the shared evolution of the several genera and families that comprise the family, why these are not considered succulents and a look at the armed defenses of many plants.  My plan is to breakout at least some of the other genera as well as I think the length of the original post may have put some readers off.]

Puya: one of the Xeric Genera of Terrestrial Bromeliaceae

The name “Puya” comes from the Mapuche Indian word meaning “point” (The Mapuche people are indigenous to Chile and Argentina.  They constitute approximately 10% (more than 1.000.000 people) of the Chilean population. Half of them live in the south of Chile from the river Bío Bío to Chiloé Island. The other half is found in and around the capital, Santiago and were mostly forced to the city after Pinochet privatized their lands giving them to the wealthy.)…the assignation is clear and the pointed, spiky, nature of this genus is immediately obvious to anyone.  But there is something easy and comfortable about the sound of the word in your mouth when you speak it…poo-‘yah.  Puya are native to the arid portions of the Andes and South American western coastal mountains.  (Oddly, two species are found in dry areas of Costa Rica.)

Puya spp., populate arid western regions of the Andes Mountains up into southern Central America.  These are terrestrial plants, relying on their roots to find the moisture that they need.  They possess the same basic rosette structure common to all members of the Bromeliad family to which they belong, including their petiole-less leaves, which clasp directly to a compact stem structure, funnelling the infrequent, and seasonal, precipitation they get into their crowns and root structures where they can take it up, a strategy very similar to Agave and Aloe which grow under similar conditions. Continue reading

Ginkgo biloba: on reproduction, evolution and anomalous existence

There are six Ginkgo trees here along Main St., on the north side Chapman Square, downtown, they are the most abundant species on the two blocks and the smelly not-a-fruits that drop in the fall demonstrate that many of them are female.. You can see the Elk fountain, one of several fountains once installed so locals could ‘water’ their horses. Only two the Ginkgos on the two blocks are male clones that I know of, the others are a mix of male and female seedlings. The male strobili are still in evidence on the trees. The female trees appear to hold their strobili on higher branches, as I could see nothing on the available lower branches with my bad eyes.

Mid-April and the Ginkgos are flowering….well, technically not ‘flowering’, because they aren’t angiosperms.  Botanically speaking, they are doing what they do instead, forming the little structures that contain their sex organs for what would most likely be failed attempts at reproduction.  Think about it, in a community filled with males no progeny will be produced.  We were on one of our walks down an inner section of Tri-Met’s Orange Line, approaching the Tilikum Bridge, when I noticed this event…I was a little surprised.

If you know much about Ginkgos you probably know about their fruit, which again is not technically a ‘fruit’ because they aren’t angiosperms and only angiosperms form ‘fruit’, but their ‘fruit like’ structures are notoriously stinky when they become ripe, smelling like what many describe as being similar to dog ‘poo’, others liken it more to ‘vomit’, either equally unpleasant, when they fall to the ground and splatter or are stepped on…one of the reasons why these trees are cloned, grafted, by the nursery industry….By cloning selected forms propagators allow us to remove the chance of purchasing a female tree…unless in their zeal to bring a particular form to market they select a tree that hasn’t flowered yet….Without looking at their chromosomes, it is nearly impossible to determine the sex of a juvenile tree.  Clones stay true to their sex, so if their scion wood, or buds, are taken from a male tree, the result will be a male clone.  Ginkgos are a dioecious species, ‘di’ meaning two, so any one individual plant produces only male or female structures, so it takes two trees, of opposite sex, to produce viable seed.  Monoecious means that an individual plant produces male and female structures.  In Ginkgo spp. and the non-flowering gymnosperms these sexual structures are called stobili or singularly, a strobilus. Continue reading

The Carrizo Plain National Monument: Super-bloom 2019, our vacation early in the cycle

The soils here, on the bottom of the Plain, are quite alkaline and nutritively poor. These bare areas occur almost randomly and aren’t the result of foot traffic. While technically termed a grassland, across much of the Monument grasses appear to be a minor player, occurring much more frequently lower on the framing hills. It makes one wonder what do the cattle eat? I imagine much of this was never farmed either. Dry land farming was always a chancy endeavor in the West. Places like the Millican Valley, east of Bend, OR and points south, were the sites of many a failed dream and such farms, after much promotion and the aid of several moist, milder than normal years. I don’t know the history of dry-land farming on the Plain, but it must have been difficult.  Semi-arid grasslands in general are fragile landscapes. Plowing them can lead to a rapid loss of organic matter and with it the ability to retain soil moisture reducing one’s chances for success even more. The native people left here after having been resident here for centuries. Is it drier today???

Why go visit the Carrizo Plain National Monument?…it is the last, significant, mostly intact, natural grass land in the state of California and puts on a floral performance that can be a showstopper when weather patterns produce sufficient rain over winter and early spring.  This area was largely overlooked as the much larger Sacramento, San Joaquin and Salinas Valleys, also natural grasslands, attracted the interest of agriculture and settlers.  The intensity and scale of agriculture in those valleys is mind-boggling, almost numbing.  Today the big three support only small remnants of their former native biotic communities…much like the Willamette Valley here in Oregon…but Carrizo is different, largely because of its geology and elevation, two factors which strongly effected both the soils and weather, making it less attractive to agriculture and isolating it from markets. Continue reading

Winter 0f ’18 -’19: Cloudy, Mild With a Chance of….On Weather, Zones & Plants

It’s 41ºF at 5:30am on Mar. 12 as I begin to write this.  We appear to have come out of the longest sustained ‘cold’ period of the winter of ’18-’19 which began on February 4 and continued through Mar. 11, a period of 36 days.  Over those days we had freezing minimum temps at PDX, the official NOAA reporting station for the Portland area, on 26 of them.  On two of those days, Feb. 6 and 7, PDX recorded the winter’s lowest temp, 23ºF, making it a zn 9a winter, mild for us historically and especially so for the temperate US as a whole, much of which was experiencing its own much colder temps.  It’s mid-March and our high temps have climbed well above what they were and our forecasts call for milder, more ‘normal’ highs and lows now locally.  It looks likely that not only are we going to be on the ‘warm side’ of normal, but that our lows have shifted into a pattern well out of the freezing range.  (State ODF meteorologist, Pete Parsons, calls for a pattern of slightly warmer and drier weather than normal over March, April and May with the highest chance of this during May.) 

While weather consists of moments, recorded data points, we attempt to make sense of it in its patterns over time…our experience of it.  In this we are much like our plants.  Plants too have their ‘expectations’ of the weather and those conditions that take them outside of them, outside their familiar patterns, the relatively quick changes and perturbations, as well as the longer sustained patterns, and extremes, are ‘noticed’ and make a difference.  How does this winter compare? Continue reading

Fabiana imbricata: the Andean Un-Tomato, a Non-Heath That Looks a lot Like its Cousin Cestrum

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Fabiana imbricata has an appearance much like the upright and shrubby Erica arborea…maybe mixed with an upright form of Rosemary…providing a remarkable texture in the garden.

In gardening and botany one of the first things we learn is that not everything looks as we might expect that it should!  Fabiana imbricata, is a member of the Tomato Family, the Solanaceae, yet, if you don’t look too close, it looks like it might belong to the Ericaceae.  At one time I was planning to take advantage of this similarity as I was attempting evoke a South African feel in part of my garden substituting this for one of the many tender South African heaths as the correct Erica species are either too tender, of borderline hardiness for my conditions or are simply difficult to come by.  It was sharing an area in the garden with Restio capensis, Eucomis spp., Melianthus spp. and others to give an impression of South Africa, not a strict species for species duplication of a community.  I didn’t quite pull it off….I’ve done much the same thing when substituting tropical looking temperate plants for the real thing when evoking a tropical feel.  It’s a matter of manipulation…a sleight of the garden hand.

Its Chilean Home and Garden Merit

Fabiana imbricata is not from South Africa, though it shares Gondwanan roots, and is endemic in Chile, occurring very frequently throughout much of its Andean range.  It is in fact identified as a ‘keystone’ species strongly effecting the composition of its local plant communities.  It can be found growing from well into the dry region of Coquimbo in the north, just south of the huge Atacama Desert, south into the wet Aysen region with its many islands and inlets south of the Lake District or Zona Sur.  The vast area stretches along much of Chile’s length which can be driven, on often tortuous mountain roads, for over 1,700 mi., stretching from the arid city La Serena to the small, rainforest town of Tortel, in the south, a distance almost 500 miles further than the drive from Vancouver, BC to Los Angeles, CA….There are not that many plant species in the world that span a similar latitudinal range with its accompanying climate differences.  As you look for this plant moving from north to south through Chile, the soils and its particular niches change along with the temperature and rainfall.  You are more likely to find this growing exposed in rocky scree in wetter regions to the south, while it tends to be more commonly found on sites more protected from the sun’s intensity and into better soils as you move into the arid and hotter north, more protected from the sun’s tropical intensity.  No surprise there, but overall this is an adaptable plant succeeding in cool rainforest to arid, desert like, conditions.  As would be expected across the more arid portion of its range fire is an important factor in maintaining the plant communities balance, riding it of other competing woody plants  and even aiding it in germination, when followed by ample winter/spring rainfall, though this is obviously not essential for its continuing survival in rainforest areas where fire is much less frequent.   This is a very adaptable species and as we live near the Pacific Coast in the northern hemisphere, which mirrors much of the range of conditions, we should be able to have success with it, if we pay attention to its cold limits.  Those away from the Pacific Coast, especially those with ‘continental’ climates or strong influences from them, will have to pay closer attention. Continue reading