Category Archives: Landscapes

On Plant Drought Tolerance and Gardening in the Arid Oregon High Desert

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The Dry Canyon in Redmond, Oregon, which for 200-300,000 years contained an earlier version of the Deschutes River. The rivers course was changed by an eruption from the Newberry Volcano, a massive shield volcano with over 400 vents 40+ miles to the south. A later eruption partially filled the canyon with lava. In this section the canyon was filled raising its floor so that it’s around 70′ deep, its two rims separated by about 700′.

Drought tolerance is an interesting topic. I’ve written on it before, but now have some additional thoughts to add, in part because we have recently moved to much more arid Central Oregon. A drought tolerant plant in Portland is a very different thing than one here where annual precipitation can vary from around 13″, very rare, down to as little as 5″, commonly 8″. While Oregon in general is considered to be a mediterranean type climate with dry summers and wetter winters, Redmond’s climate is strongly influenced by drier continental patterns. This last January, ’23, we received only 1/4″ of precipitation while Portland had 7.32″ about 120 miles to our northwest, on the ‘wet’ side of the Cascades. Drought tolerant then means different things in different regions and can vary widely within a region along with soil conditions, slope and aspect (which direction a site is oriented). Generally speaking, drought tolerance refers to the ability of a particular plant to endure periods in which available soil moisture is below that needed to support the plant’s metabolism. A tolerant plant can ‘bridge’ these naturally occurring ‘dry’ periods. An intolerant plant will suffer cellular, even structural damage and may be unable to flower and produce seed. Health is compromised should the drought last too long, resulting in internal physical damage and leaving it more subject to infection or infestation. A drought tolerant plant will have the capacity to respond in a healthy manner when soil moisture levels return to those that support active growth. Within these limits the stress it accrues does not compromise its health…beyond it though….Damage is accumulative. String a series of drought periods together and a plant’s capacity to recover is compromised. Because patterns of precipitation, of water storage and movement, vary widely across the earth, regions and sites have different plant communities associated with them. The condition of drought stress then varies with the location and the species. A drought tolerant plant on one site may crisp on another drier one. Of course this can work in the opposite sense as well, that a site may be too wet, but that’s another story. In the case of the PNW and many other regions, it is also the timing of the precipitation, when it occurs during a plant’s cycle of growth and dormancy. Continue reading →

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Why Bad Things Happen to Good Plants?: On Root Problems, Root Washing, Nursery Practices and Customers

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“To be, or not to be? That is the question—Whether ’tis nobler in the mind to suffer The slings and arrows of outrageous fortune, Or to take arms against a sea of troubles, And, by opposing, end them?”  Hamlet.

Is the question we face as gardeners as simple as, To ‘root wash’ or not to ‘root wash’, before planting?  To some today it has become ‘heretical’ to suggest that it might not be just a necessary corrective, but an unmitigated good…and not doing so dooms a plant to failure.  The practice of ‘root washing’ in its present form, is relatively new to gardeners.  Horticulture, which is a system of techniques, traditions and science, that goes back to our own species’ first intentional involvement growing and selecting plants, has not always included it.  Practices develop over wide spans of time.  Many are retained, others pass away. Root washing has been around as a method to assess damage to root systems, to ease and make more efficient division, to study root growth or cleanse them of particular infestations.  ‘Bare-rooting’, during a plant’s winter dormancy in temperate regions, has historically been done in the field when harvesting or transplanting many deciduous trees and woody plants for shipping and ease of transport.  In some circles today root washing has become an almost literal flash point, pitting proponent against opponent, ‘science’ against ‘tradition’…yet another fracture line to divide society. The road of the absolutist, as with many other human practices, tends to create conflict as evidence of correctness is lobbed back and forth.  My own view is that, like so many other things today, the subject is somewhat ‘grayer’. Science can be on both ‘sides’, or neither, and reality is rarely so simplistic. Continue reading →

Agapanthus for the Maritime Pacific Northwest: Not all of these are well suited for us…or are they?

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Agapanthus ‘Hinag’ syn. ‘Summer Gold’ a Japanese selection brought to the US by Barry Yinger.
Agapanthus ‘Peter Pan’
Agapanthus ‘Storm Cloud’
Agapanthus ‘Tinker Bell’

A fellow gardener asked the question about whether there were a list of sure thing Agapanthus, plants that a beginner could confidently choose and have success with in most of the maritime PNW.  I’m going to say no.  All of these are South African natives and while many of us can grow these in our gardens, because our conditions overall are marginal, a gardener is going to have to possess a good understanding of their site in particular and some knowledge of the cultivars that they are choosing.  I’m going to borrow here from Manning and Goldblatt’s book, “The Color Encyclopedia of Cape Bulbs”, which discusses the bulbs of the Cape Floristic region and those adjacent areas spilling over into other parts of South Africa. Agapanthus species are native there, endemic in fact, occurring naturally no where else in the world.  I’m also relying here on the SANBI website, the South African Natural Biodiversity Institute which has put together an incredible national program, which all countries should be building for their own countries.  Being a South African plant aficionado I visit it frequently. To this I add my own observations and speculations, having grown several Agapanthus over the last 25+ years in Portland: These come from warm temperate and subtropical areas in South Africa, 10 species total, 3 limited to the Cape itself, all of which tend to occur in rocky grasslands.  Other botanists have downgraded 3 of Manning and Goldblatt’s species and given them subspecies status recognizing only 7 species. Continue reading →

Spreading the Wealth: Taking Advantage of Monte to Broaden a Teachable Moment

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I’ve been taking advantage of people, striking when they are most sensitive, hungry for anything that is outside of their homes and families…I’ve been hanging informational signage amongst Monte’s floral neighbors as they come into bloom, not all of them.  Some will remain anonymous like my Aristolochia semperivirens, an unassuming Dutchman’s Pipe, that is only noticed by the more discriminating of visitors.  Others issue stronger ‘calls’ and so signage seems appropriate.  Many people are taking the time to read them or take pictures of them for later consumption or to make sure they don’t forget.  Many thank me for them.  Who thought ‘school’ could be so cool!  Anyway here is what I’ve hung out in the garden.  Some will come down as their season ends, like the Pacific Coast Iris, others are waiting in the wings.

Monte on May 17

Agave montana

My Agave is flowering. The ‘spike’ you see growing upwards is the ‘peduncle’, the main flowering stem. As it meets its maximum height ‘branches’ will form near the top, from beneath the ‘bracts’, the tightly adpressed leaves, on which will form the yellow flowers. It will form a panicle, a ‘candelabra’ like structure. Agave are monocarpic, meaning they only flower once and then die, after it produces seed. It is 20 year old. Many Agave produce ‘offsets’ or ‘pups’ that can be grown on into mature plants…not this one!

This is a mountain species from Mexico’s Sierra Madre Orientale, where it is found between 6,000’ and 10,000’…not from the desert. This species is relatively new to the trade and was only formally described in 1996, 24 years ago. I’ve been told that this might be the first one to flower in the NW. Its native range experiences a temperate climate and receives its heaviest rains late summer-early fall during the hurricane season. It can experience freezing temperatures and even some snow there in open Oak-Pine forest. It begins its flowering process in Fall, then ‘stops’ for a period during winter, finishing the process in Spring/Summer. Most Agave are tropical/sub-tropical plants from deserts and are grown here in pots. There are 200 or so species, 3/4 of which are endemic to Mexico, found only there, none are native outside the Americas. Only 22 species are found in the US, from California into Nevada, Utah, Arizona, New Mexico and Texas. 3 are native to Florida.

Portland and the Maritime Pacific Northwest provide challenges to growing any Agave species and hybrid. Agave are native where climates tend to have most of their rainfall in summer. Here we have dry summers and wet cool/cold winters…this is the opposite of what most Agave need and will lead to rot and/or fungal foliar disease that can disfigure or kill most Agave species. Siting considerations are extremely important. They generally require full sun and excellent soil drainage. Here good air circulation helps foliage dry in winter. Sloping sites also help with soil drainage. Tilting the plant when planting is helpful as it helps the crowns stay dry. Some gardeners plant these under their eves or erect shelters over their plants to keep the crowns dry over winter. Agaves will require some summer water to grow well especially if they sit in dry soil all winter and spring….

Many Agave are becoming rare across their natural ranges in Mexico because of development and agriculture, a cause which threatens so much of our own natural flora in the US and around the world.

This species is not used to make Tequila! In its home range Agave are pollinated by hummingbirds, insects and nectarivorous bats, bats which are non-native here.

Beschorneria yuccoides ‘Flamingo Glow’. My plant this year took a year off from flowering. To the lower right is Agave parryii ‘Huachucensis’
Beschorneria septentrionalis on a drippy morning


Beschorneria septentrionalis
(False Red Yucca)
There are seven species of Beschorneria, from forests of the higher mountains of Mexico down into Guatemala. This is the most northerly species occurring in NE Mexico, not far from the range of Agave montana. Unlike their cousins, the Agave, all but one of these are ‘polycarpic’, they can flower year after year. These form a substantial rhizome which spreads gradually when the plant is well sited, forming colonies. This one does so only slowly.
Another Asparagus family member, hardy through our zn8a, down to 10º for short periods, if you can keep the crown dry enough. This one struggles a bit and I have to remove a fair amount of rotting leaves every spring…I should move it and it would do better, but I haven’t…it wants better drainage. This particular site is a little wet close to our house which tends to concentrate rainfall a bit without any eave over hang to catch it.
As an open pine/oak forest dweller these are tolerant of relatively shady sites. Mine get some shade.
It’s inflorescence typically form these bright red stems with its sparse branching and hanging, narrow, bell shaped flowers. Part of their corolla is green.
At the top of my stone steps is a selection of another species, Beshorneria yuccoides ‘Flamingo Glow’, which has a buttery colored mid-rib on each leaf. from forests of the mountains of central/eastern Mexico.

Echium wildpretti, on any other year, this would have been the street side star!



Echium wildpretii
(Tower of Jewels)

There are 70 different species of Echium and several subspecies, in the same family as the commonly grown Borage. 27 species are endemic (occur no where else) to macronesia, the Canary, Madeira, and Cape Verde archipelagos lying in the eastern Atlantic close to Portugal, Morocco and west Africa. While the continental species are all herbaceous, dying to the ground over the winter, all but two of the island species are woody, with permanent stems. Echium wildpretii is one of these two.

Echium wildpretii can grow as high as 10’ in its home territory. It is generally a biennial, flowering in spring here, though sometimes, it can ‘wait’ and bloom the third spring. It is monocarpic, dying after producing seed. This plant is just under 9’ and is the tallest individual I’ve ever had in the 15 years of growing this. The plant grows in the ravines of Mount Teide, 12,198’, a volcano on Tenerife, 28ºN latitude, in the Canary Islands, so it has a very restricted range. It requires full sun and arid/dry conditions. With our much wetter winters it is best that you provide this with very good drainage as growing them in cold winter wet soil will decrease their cold hardiness and could lead to rot. Plant on south facing slopes and retaining walls with good air circulation. It is marginal, said to be hardy down to 23 °F.

The species E. pininana, the other Macronesian herbaceous grower, goes to 13’ having much the same form with blue flowers. E. candicans is a short lived woody shrub, which grows to 6’, both are grown here as well. In California these two and others are common some often escaping into the wild and crowding out native species. Here, these are marginal and survive only in protected areas killed by normal to colder winters.
Check my blog at Garden Riots. Annie’s Annuals sells several of these: https://www.anniesannuals.com/search/?q=echium

Grevillea x ‘Pink Pearl’



Grevillea x ‘Pink Pearl’

Grevillea is a genus of 360 species of flowering plants native to Australia and north and west to the Wallace Line. They vary from ground huggers to a tree over 100’ tall. They belong to the Protea family which includes many bizarre and large cut flowers used in the florist industry. They are pollinated by many Lepidoptera, butterflies and moths as well as by Honeyeaters, a group of nectar feeding birds native to their home range related to South African Sunbirds, but not at all to our Hummingbirds. Hummingbirds and bees visit these here.

Most Grevillea are not hardy here in the NW so choose judiciously. To find reliable plants check out the offerings of Xera Plants on SE 11th and or take the trip out Sauvie Island to Cistus Nursery, they have a section of Australian plants. There is a great review of NW hardy Grevillea at Desert Northewest’s site, https://www.desertnorthwest.com/articles/grevilleas_revisited.html

Grevillea readily hybridize. This is thought to be a hybrid of G. juniperina x G. rosmarinifolia. If you give it what it wants it is hardy down to 20ºF, maybe lower. I planted this one 6 years ago here. One winter, ’16/’17, I lost about 1/3 of the top. That was Portland’s fifth coldest winter ever in terms of number of days with freezing temperatures…so not typical. (https://weather.com/storms/winter/news/portland-oregon-worst-winter-city-2016-2017) I suspect another degree colder or with another day of sustained freezing, I would have lost the entire plant.

These are relatively fast growing and can take a hard pruning. In Australia these are often used as hedge plants causing them to grow densely with their pokey needles, quite a barrier! I prune mine regularly to limit its size while retaining its softer look with drooping branch tips.

These are sun lovers and require well drained soil here. They are drought tolerant in the Pacific NW requiring no water after establishment. It is essential that should you choose to fertilize that it include NO PHOSPHOROUS!!! Phosphorous is plentiful in our soil already and adding anymore can prove deadly to Grevillea and also to most all members of the larger plant family. These come from regions with phosphorous poor soils and are very well adapted to searching it out, so…don’t add any!

x Halimiocistus wintonensis ‘Merrist Wood Cream’



x Halimiocistus wintonensis ‘Merrist Wood Cream’

This Rock Rose is a hybrid between two different genera Halimium and Cistus, a relatively rare even as species from different genera aren’t generally capable of crossing successfully. The parents are both Mediterranean plants and this plant benefits from growing under like conditions, warm to hot, dry summers and cool/mild and relatively wet winters.

This plant has grown here for 10+ years on this south facing slope in unamended soil. It benefits from a light cutting back after flowering to help keep it compact and to keep it from falling/splaying open. All of the Rock Roses have a tendency to splay open with time here as our rich soil tends to push them to produce extensive soft growth. Don’t cut these hard, below healthy growth, if you do you are likely to end up with dead stubs unable to resprout. I’m planning to take cuttings of this, root them and replace this plant as it has gotten rather ‘leggy’ over time.

There are many fine Rock Roses available from these two genera that can be grown here.

Lobelia laxiflora ssp. angustifolia Heavy with bloom this Lobelia began flowering almost a month ago.



Lobelia laxiflora ssp. angustifolia
This Lobelia, with its narrow hot red tubular flowers, from Mexico, is reliably evergreen here except over our coldest winters, which can kill it to the ground, but from which it springs back. It often blooms for 7 months or more in the year. As you might guess it is attractive to hummingbirds. This plant is rhizomatous and in too good of conditions with summer water, has a tendency to spread, though it does so compactly. It is better ‘behaved’ under drier, more spare, conditions.

Lobelia are a large and varied genus with 415 species occurring primarily in tropical to warm temperate regions. I also grow the less commonly grown species type, sometimes called ‘Candy Corn Flower’ with broader leaves which is less robust for me here, but showy in its own way.

I grow Lobelia tupa on the east side of our house. It’s a large growing Lobelia from the Andes of Chile with hooking dark red large flowers. I have others on my list including the large pink flowering species, L. bridgesii, to acquire and am somewhat enamored with the ‘Tree Lobelias’ limited to the Hawaiian Islands.

Mimulus (a.a, Diplacus) aurantiacus ‘Jeff’s Tangerine’



Mimulus aurantiacus ‘Jeff’s Tangerine’

Sometimes known as “Sticky” or “Bush Monkey Flower” this plant is native from SW Oregon down through most of California into Baja. A ‘sub-shrub’ this has a somewhat woody base from which sprouts softer herbaceous stems that carry the leaves and flowers. Found from coastal bluffs east into the Siskiyou and Sierra Nevada mountains, these are ideally suited to our mediterranean climate with its summer dry/winter wet precipitation pattern.

Typically, where I’ve seen it growing in situ it is taller than my plant with a much more substantial woody base. At Point Lobos, on the central California coast, these can be over 4’ tall and form impenetrable thickets. Here with our rich soil it grows more lushly and flops. My plant is ten years old and will bloom all May through September in waves, almost never completely out of flower.
Place it in full sun. Mine receives only sporadic summer water. It grows in unamended soil on a south slope so it has good surface drainage. It benefits from free air movement and good soil drainage. There are several color forms available from specialty nurseries.

One of ten or so varieties I have, Iris x pacifica ‘Pacific Rim’



Pacific Coast Iris
(aka. pacifica)

There are 12 Iris species in the group native to our region stretching from southern California northward into Washington state, in a narrow band between the ocean and the Cascades and into California’s western Sierra Nevada. Most of these are limited to California and southern Oregon to areas that receive enough rain and are often limited to places closer to the coast. The Willamette Valley and Washington is mostly limited to one species, the deciduous, woodland edger, Iris tenax.

Hybridizers have taken advantage of their tendency to cross and are found in a wide range of jewel like colors, white, to yellow, red, russet, blue and purple. The hybrids are evergreen. These must generally be searched out as their production is relatively low because these Irises are difficult or impossible to grow anywhere else in the country because of soil and climate differences too far out of their ability to adapt.

The hybrids are drought tolerant in our western gardens. Plant them with plenty of sun, then water to establish. Don’t plant them anywhere where the soil remains soggy into the summer, they need to dry out. It is important to leave them undisturbed after planting. If you choose to move or divide them, wait until the fail rains, when they are producing new roots. They will likely die if messed with during the summer. See my blog: gardenriots.com.

Sphaeralcea x ‘Newleaze Coral’ The first two little flowers of the long season.



Sphaeralcea x ‘Newleaze Coral’
(Glog

The genus Sphaeralcea is native/endemic to the intermountain west of North America, occurring between the Rocky Mountains and the Cascades and east of the Coastal mountains of California. Some can be found in eastern Washington, Oregon and Idaho on south into northern Mexico. They like sun, heat and thrive in poorer mineral soils and are drought tolerant here once established.

‘Newleaze Coral’ earned its garden pedigree in the UK and is a stellar performer here in xeric beds. Sphaeralcea is a member of the large Mallow family which contains 244 genera with 4,225 known species. Well-known members of economic importance include okra, cotton, cacao and durian. There are also some genera containing familiar ornamentals, such as Alcea, Hibiscus, Malva and Lavatera, as well as the genus of trees, Tilia. Commonly called Globe Mallows, this Sphaeralcea will easily bloom for 5 months bookending the summer months.

The Flowering of Monte, Social Media and the Hordes

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Where has the last month gone??? This is a brief, I promise, update to those of you who’ve been following the flowering of Monte, my Agave montana, this spring. Ever since Monte went viral on social media, life has been a little crazy here. On April 20th the bracts at the top of the inflorescence separated enough that I could see down inside to the tightly clustered buds below looking a lot like a bunch of chicks with their beaks upheld…then the changes became visible, changing noticeably on a daily basis…and everyone began to see it. Our regular walkers in the neighborhood, bicyclists, commuters and the many who’s regular workdays brought them by…and I swear everyone of them must have been posting!

  • One flower, from the stigma tip to the bottom of the ovary and pedicel attaching it.
  • Each of these pillow like structures are a good 12″ across, 8″ wide and 7″ tall.

It did not take long at all before Monte became a destination. Facebook, Instagram, Reddit, Next Door, Monte’s evolving visage was appearing everywhere and the number of visitors, which was at one time early on easy to handle, quickly began to approach sideshow numbers and atmosphere. Many seemed to have completely forgotten about the pandemic and sheltering in place. What was once a varying stream flow became a flood. I would go outside to take pictures, make notes and measure, ever earlier, as early as 5:30am, and people would be here, for Monte. At first I would ‘hold class’, answer their questions and try to educate them about the processes of plant growth, the thumbnail version, and people seemed genuinely curious. I tried to take advantage of what I saw as a ‘teaching moment’…but, the numbers quickly increased and many seemed more interested in snapping their IG pics and getting in on this event. But this event wasn’t like the one day happening of last year’s eclipse or the brief period of the blooming Corpse Flower up on the WSU campus…but people came like this would be their only chance. Continue reading →

Weather Snapshot: What’s Been Going on Out There Lately

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Did you know that the all time record lowest temperature in Portland occurred on this date, Feb. 2, it was -3ºF. In 1950! A notable year with 6 consecutive days that still are the coldest on those dates, from Jan. 29th through Feb. 3rd., 8º, 10º, -2º, 1º, today’s -3º and tomorrow’s at 4º! 1950 also still holds the record cold temps here for Jan. 14th at 9º, the 16th and 17th, both at 8º!

We moved to Portland, from Bend, in the fall of ’85, a year that gave us the coldest Thanksgiving week ever here. I remember moving a couple yards of gravel frozen into an ice cube, getting blisters in the process. From Nov. 22-31, six of the daily record lows from 1985 still stand, dropping to 13º and 17º at the coldest. This was a surprise to me coming from cold Bend where this would have been normal. Continue reading →

Agave montana: Monte’s Flowering Attempt…and What’s Behind It

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Taken in ’15.
Taken in ’15 this shows the typical pattern of leaves as they emerge from the center of the rosette.
Agave montana with a friend’s Mini- taken last year, Sept. ’18
Taken Sept. 29 this closeup shows the different pattern as the primary peduncle begins to shoot up with its pink/red coloring and the congested pattern of thinner, narrower, bracts crowding around it. This change can be seen in any Agave as flowering beginns, showing before the peduncle arises.
We came home at the end of Sept. from a week at the beach and found our Agave montana beginning to ‘shoot’.

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 →

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.

Fig4-5-color

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!

Aug. 26, 2018 I could have taken a similar picture anytime over the last several years. The stem is completely prostrate. You can see dried leaf bases lost over the years. A different angle would have shown additional rooting along part of its length.
Aug. 10, 2018 This shows the center of gravity problem! Growing in the ground, such as the plants at Boyce-Thompson the crowns were supported by the ground and had a less pronounced ‘lean’. The desiccating leaves, especially the lower ones, is already well advanced here, to me indicating a lack of reserves having lost so many leaves over the years from which to draw, especially given that there is not any prominent ‘heart’ tissue.
Aug 23, 2018 looking a bit spindly as it leans back toward the pots center. The peduncle has much more widely spaced bracts.
Aug 26, 2018 the shriveling, desiccating leaves.
Aug 28, 2018 Here, along the upper half of the peduncle the bracts are separating as the secondary peduncles and buds emerge and develop.
Aug 30, 2018 The secondary peduncle nearly fully extended out with tertiary branching spreading the clusters of flower buds held in a crowded groups in umbels.
Sept 3, 2018 Where the secondary peduncles, branches, form the main peduncle, stem ‘zags’ slightly away giving it an alternating, spiraling form. Here you can see the base-up process of development as branching lengthens and buds mature.
Oct 27, 2018 The entire process has been slowing down, the flowers in the lowest ‘branch’ opening on Oct. 12. Here you can see my neighbor’s bees busy working the flowers, some of the long canoe shaped anthers split open and dehiscing their pollen. The overall structure of the inflorescence and the anthers provide the main visual ‘show’ when these bloom the corolla, or petal structure and perianth is secondary.

 

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

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[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

Puya chiliensis
The inflorescence is very ‘spiky’ in its structure its many ‘arms’ covered with buds.
Each bud will open over time giving a long season of bloom.

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 →

A Course Correction: The Wild and the Human, On Repairing the Relationship Between Politics, Economics and the Environment

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“We are the odd ones, with bright eyes, that see the wonder of a bountiful world.  We don’t look through rose colored glasses…we’ve only removed the veil that breaks and blinds….Now, to cut the strings that tie us to the lie. ”  Lance Wright, Jan. 2019

Echinops ritro in front of a Miscanthus gracillimus several years ago at Holladay Park. A series of perennial beds were created with help from a notable local designer. For a variety of reasons related to budget, staffing and vandalism, the beds declined.  Beauty, that necessary elixir, truly abounds, but we must be cognizant of the forms in which we accept it and be committed to what it requires to flourish.

Gardeners are my people…well, actually, so are botanists, horticulturists, entomologists, ecologists, the weekend outdoor adventurers who in regular moments of awe, pause to take in the daily wonder of the world…anyone, really, who works with or has become enamored with the living natural world (and I’m going to include geologists too, at least those not taking their livelihood from resource extraction).  I have a theory, that as our modern world becomes increasingly urbanized, and transformed by our use to that which supports urban living, more of us are becoming consciously aware of what we are losing, of the natural world that has been sacrificed, developed, along the way…and in ways, large and small, many, but still far too few of us, are choosing to make our lives reflect this understanding. We question the ‘stuff’ we have crowded our lives with, that ‘stuff’ we’ve spent our lives to procure while following the dream we’ve all been sold on.  Many of us garden on whatever we have available to us whether it’s a quarter acre, a Juliet balcony or a kitchen counter space.  We plant gardens for food or to support pollinators, to have something green and growing in our homes, we grow small succulents for their simple beauty, flowers for the vase or plants that provide cover and fruit for songbirds, there are many reasons…and we do this for the pleasure that it gives us, for the satisfaction that we are doing something to heal an increasingly ‘broken’ world.  Yet the world continues to spiral down into more ugly chaos, in spite of our increasing awareness…it is not enough.  I find myself drawn even more into the wonder and beauty of a single plant, the ‘miracle’ of life and the amazing complexity, the inter-relatedness of living communities…because, in spite of how our society views this planet and the countless organisms it routinely dismisses as secondary, and unnecessary or of little commercial value…life is in fact the center of meaning and value. Continue reading →