It’s October in Portland and my Agave montana is in the process of flowering…I know, we’re heading toward winter, with its rain and average low down into the mid-30’s with potentially sudden damaging temperature swings from mid-November into March dropping below freezing to the low twenties, with extremes some years, generally limited to the upper teens, though historically, some areas have dropped into the single digits, those Arctic blasts from the interior….Winter temps here can be extremely unsupportive of Agave’s from ‘low desert’ and tropical regions. Combined with these cool/cold temperatures are our seasonal reduction in daylight hours and its intensity (day length and angle of incidence varies much more widely here at 45º north) and the rain, ranging from 2.5″ to 6″+ each month here Nov.- Mar., resulting in a ‘trifecta’ of negative factors which can compromise an Agave, even when in its long rosette producing stage. Any Agave here requires thoughtful siting with special consideration for drainage, exposure and aspect. For an Agave, conditions common to the maritime Pacific Northwest are generally marginal, yet I am far from alone in my attempts to grow them here. Previously, in April of 2016 I had an Agave x ‘Sharkskin’ flower, a process that spanned the summer months, taking 7 until mid-October to produce ripe seed. I was initially a little pessimistic this time about A. montana’s prospects. Why, I wonder, if plants are driven to reproduce themselves would this one be starting the process now? Continue reading
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.
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 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.
[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
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
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
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
Another Jimi Blake plant. I have history with this choice of Jimi’s…and the NW has a history with Bananas as well!
There’s an old hand colored postcard floating around the Washington Park office of bananas as part of an elaborate bedding out scheme around the ‘Chiming’ Fountain, near the Sacajawea statue. If memory serves, it is Ensete ventricosum, which have a uniquely identifiable form. Back in the day, Ensete v. seems to have been a thing. It is a non-suckering species, unlike the spreading, mat forming Musa spp. and cultivars, and is commonly grown from seed. It is interesting to me that they were available prior to the 1900’s and relatively common, probably up to 1929 and the stock market crash…at least for the more horticulturally involved, as specimen in annual display beds. Gardeners must have dug them out in the fall and hauled them to greenhouses to ‘protect’ them for use in the following year. I did some research in the early ’00’s of catalogs and area nurseries to get an idea what was available in the 19 teens, and of a few Park’s planting plans of this period, influenced by the Olmsted’s and under the direction of Emanuel Mische…. Compared to typical planting plans of more recent years these were relatively adventurous, especially given that acquiring such plants was often a much bigger deal in the nineteens and twenties than it is today. Back then if you weren’t wedded to a particular clone and you could find seed for it, exotic bananas were a possibility. There was an excitement around the novel and exotic that had spilled over from Europe. Local inventories also included a wide array of bulbs which could be more easily shipped than grown plants widening the range of choices. They often times had choices that you would have to spend some time searching for even today. With the economic collapse of ’29 it is no surprise that tastes and possibilities became much more conservative. There were those who clung to the use of some of the old exotics, but you would have to look hard for them in public places and gardens. Botanical gardens became refuges for the forgotten and newly collected. It took many years before enough of the gardening population reclaimed their sense of wonder and awe enough to create a new market for the plant’s of the world. We experienced a similar contraction of the nursery industry in the Fall of 2008 when the real estate boom stalled and demand for plants collapsed causing the closure of many nurseries and a reduction in the selection available from local garden centers. Locally gardeners have become increasingly interested in such plants and have continued to support the many small specialty nurseries that provide them Continue reading