Category Archives: Site Analysis

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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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

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

The Fascicularia and Ochagavia Question: Two Worthy and Relatively Hardy Bromeliads

 

The inflorescence of Fascicularia bicolor with its blue flowers. The center of the foliage on a blooming rosette, turns red when the flowers appear and then, like many Bromeliad, that rosette dies replaced be previously formed offsets. My blooming plant had multiple rosettes at the time, three of which bloomed. Taken in my garden, Sept. of ’17.

If you’re not into blood and guts, consider this genus, as on my scale of one to ten as described above with ten warning of near complete evisceration if one is fool hardy or reckless, this one’s a solid 4, dangerous enough but not stupidly so.  Fascicularia pitcairniifolia.  You would think that in a genus composed of one or two species things would be pretty well settled taxonomically, guess again. Originally described as F. bicolor it was reclassified as F. pitcairnifolia and later changed back to F. bicolor.  Subspecies were proposed.  Changes retracted.  There are significant differences in the sampled populations, but were they sufficient to constitute separate species??? Adding confusion at a different level are those who say the species name indicates that it is from Pitcairn Island.  It is not.  The specific epithet simply recognizes a similarity to the foliage in genus, Pitcairnia, another Bromeliad member.  This Fascicularia is from the lower Chilean Andes, allegedly north of the other Fascicuaria species, F. bicolor which is suppose to be slightly hardier and occurs at least occasionally as an epiphyte!  Some botanists have argued that F. pitcairnifolia possesses thicker, slightly wider leaves. and some minor differences in the timing of flowering and is reputedly slightly less hardy.  The ranges of both overlap  Good luck sorting this out. Continue reading

Growing and Understanding Globe Mallows in the Urbanized Maritime NW: Sphaeralcea spp. and Cultivars

Every plant evolved in and lives in context.  They are dependent upon it for continuing support, not just for their survival, but for their well being as they grow, mature and attempt to reproduce.  It is not just competition out there.  Though we may order them from a catalog, grow them from carefully collected seed, receive them as gifts from a friend or purchase them from the shelves or rows at a garden center, they are individual plants, removed from their context…their futures’ will be short if we don’t make some attempt to recreate it.

Sphaeralcea ‘Childerly’, from the Dancing Oaks catalog, though it’s not currently listed.

Sphaeralcea are often called Globe Mallows and are another member of the large Mallow Family, the Malvaceae, some 244 genera with 4,225 known species.  I’ve written recently of Anisodontea another genus of the family.  Most of the 40-60 species of Sphaeralcea are North American natives of dry areas, growing from the Great Plains west and south into Mexico, with a few occurring in South America while a few others reaching into southern Canada.  They include annuals, perennials and shrubby species, I’m looking here at perennials, all of which have very long bloom times, often spanning the entire summer into fall.

Sphaeralcea (ambigua) ‘Childerley’

Sphaeralcea ambigua, one of the largest growing species of the genus, at up to 3′-5′, often found considerably smaller, is native to the US Southwest, SW Utah, Nevada to Arizona and southern California down to Sonora and northern Baja, Mexico.  They are found east of California’s Sierra Nevada and the several other smaller ranges of southern California, which shield them from moisture coming from the Pacific.  It is the most xeriphytic of the genus, meaning, the most tolerant of drought.  The USDA breaks the species into four separate subspecies, S.a. ssp. ambigua, the most commonly occurring form across the four states with the typical orangey flowers, S.a. ssp. monticola, the one occurring at higher elevations, beyond the Sonoran Desert and covering its Nevada range, S.a. ssp. rosacea which is limited to the San Diego area east to Maricopa county in Arizona, of the warmer Sonoran Desert, with a flower that is rosy-pink and S.a. ssp. rugosa which is limited to the Mojave Desert area with the more expected orange-red flowers.  Both S.a. ssp. ambigua and S.a. ssp. monticola grow on north of the Mogollon Rim, an east-west running escarpment,  the abrupt rise in elevation marking the southern edge of the Colorado Plateau.  The other two subspecies grow below this and largely south and west of it. Continue reading

Roldana cristobalensis (formerly Senecio cristobalensis…now, Roldana petasitis var. cristobalensis)

Roldana petasitis var. cristobalensis shown here looking amazing with Aeonium arboretum ‘Zwartzkop’.  Its substantial leaves are some 8″ across, thick and velvety, the undersides of which are red/purple, like the stems.  The color often comes through in the veins along the top surface.  A very striking foliage plant.  Picture this with its close relative, Pseudogynoxus chenipodiodes, the Mexican Flame Vine, formerly known as Senecio confusus!

Sometimes called Velvet Groundsel, this plant has been living and marketed under several different names.  The first name in the heading is the one Jimi Blake ascribed to it, a name I didn’t recognize for a plant I’ve grown off and on in the past…it got lost in his list paired with a particular Thalictrum and I simply missed it…until recently.  I knew it as Senecio cristobalensis and, had I recognized it, would have included it with an earlier post in which I focused on his favorite Asteraceae.  I did actually mention the plant there simply as another Senecio that I’ve grown of value.  Here I shall treat it more directly.  The genus, Roldana, was recircumscribed in 2008 to include some 54 different species.  Other authors include as few as 48 and as many as 64 in the genus, most of which used to belong to Senecio and are native to the extreme Southwestern US, Mexico and Central America.  Most of the Roldana species are somewhat ‘shrubby’ herbs with a few, like this one woody, even tree like.  Both genera are within the Asteraceae and share tribe status as well, Senecioneae.  For the curious, Roldana spp., even more finely, are included in the sub-tribe, Tussilagininae, which includes the very commonly grown genus of garden plants…Ligularia!  On closer examination the morphological similarities will begin to stand out to most of us.  Check out all of the photos on the Wikimedia Commons page for Roldana petasitis.  Roldana petasitis is the correct species name for this plant.  With all of the shuffling and consequent confusion still going on in the world of taxonomy, especially in such a mixed large genera like Senecio, we must all be allowed our mistakes of nomenclature.  It is a volatile changing world out there. Continue reading