Category Archives: Xeric

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

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

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 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 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.

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!

 

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.

 

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

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

The Lower Deschutes River: the Incursion of Invasive Plants and our Failure to Responsibly Maintain Native Plant Communities

This picture should give anyone more than enough reason to visit here, the Deschutes sliding out its mouth into the Columbia with the Washington side of the Gorge in the distance, the low angled early evening sun illuminating everything sharply.

 

[As I go over this post yet again, July 21, the 80,000 acre Substation Fire is still burning across canyon and wheat country here.  Included in the blaze are the 20 miles of the Lower Deschutes canyon down to the campground at the confluence with the Columbia.  Much of this burned down to within 2′ or 3′ of the riverbank including the historic Harris Ranch buildings.  So, when you look at all of these pictures, with the exceptions of where the fire hopped and skipped, everything is charred.  The Oregon Wildlife Federation, formed in the 1980’s to purchase and protect this portion of the canyon, has stepped up with $100,000 to help the area recover.  It will take considerably more especially if there is any intention of making headway regarding the spreading invasives problem.]

[Now, another 2 weeks later more massive fires continue to burn across the dried up West that has just experienced another record breaking month of heat, while the president goes on ‘bleating’ and blaming it on our ‘bad’ environmental laws and all of the water we’re diverting into the ocean!  ‘F’ing! moron!]

The last time we came here was eight years ago in December.  My memory of then is much like the experience on this evening…only it was clear and cold.  The light was similar except that then the low angled sun was due to winter, with that season’s urgency, not a late Spring evening like this outing.  This time it is warm, camp is comfortable and nearby and the greens are still gathered around the river and the still moist draws and seeps.  On that day we’d gone to Hood River for my birthday, to get out of town and there was a break in the weather so we drove here to these trails at the mouth of the Deschutes, hiked along the river, returning on the upper springs trail.  Winter or summer, green only sticks around a little longer than we do, before it retreats…life is shier here, tough, but shy.  The starkness of this landscape should be read as a warning to visitors, this is no easy Eden.  Life is earned here or at least requires a strength, patience and frugality that many don’t have.  This is much the same for people as it is for wildlife and plants.   Them that don’t, can’t.  That’s why it may be surprising to some that such a place has a problem with exotic invaders.  What could possibly look on places such as this as ‘favored’?  Well, Central Asia, especially its Steppe, with its continental, cold and dry climate containing many species that see such a place as this as home, or even better, without the competitors they faced back there.  The temperature can swing widely here on any given day while the seasonal extremes can vary as much as 125ºF from high to low.  Relatively few plants can thrive in this.  The dry summers with their very limited and sporadic thunder showers, combined with the ‘wet’ winters, total only 10″-12″ or so of precipitation, plus or minus, is another major limiting factor.  Of course, near the river, the moisture problem is moderated  and a broader range of invasives can find a ‘foothold’.  We, as a people, have ‘brought’ these weeds here with us in our travels, often as a result of our commerce.  Those that have made it here are spreading.  Too many prosper. Continue reading

Echium wildpretii in Bloom

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This Canary Island native has a tougher winter climate here to endure than back home.  As an alpine growing on Tenerife, this plant is said to tolerate down to 20ºF with its characteristic dry winters…not so here.  After a relatively mild winter here in inner SE Portland the later half of February chilled down with a little snow as shown here on Feb. 22.  The official weather station at PDX recorded nine days at or below freezing in February ranging down to 23F on the 21st.  This was a fairly ‘normal’ February temperature wise for us, though with just less than 2″ of precipitation, about half of normal, which could have aided its survival.  At my location in inner SE we can record 5-6º warmer than PDX though we often move right in step,  January was milder PDX recording below freezing temperatures on only two dates, the first and second…and we were right around freezing both of those days with just under 5″ of rain for the month.  During December we were ‘blocked’ from lower temperatures that hit most of Portland.  PDX recorded 14 lows below freezing, we suffered only six getting as low as 25º on one of them.

Continue reading

Argyle Winery: A Look at a Landscape in Dundee as an Example for Those on the Trail to Xeric Design and Sustainability

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This strip planting dominated by a Carex and a taller, 7′ or better, spine of the feathery Rhodocoma capensis from South Africa, rated at zn 8b. Mine, in my home garden, survived two nights down to 15ºF this last January with very little damage.

I don’t usually do this, write about a particular landscape with which I have no history, so this is a bit of  a departure for me.  I’ve know Sean Hogan for quite a few years, consider him a friend and a highly influential mentor of sorts.  His encyclopedic knowledge of plants, his boundless enthusiasm, has been infectious and inspirational over much of my career as a horticulturist while I was working for Portland Parks and Recreation.  I’ve benefited from the existence of his nursery and his commitment to horticulture picking his brain for plant and design suggestions as I attempted to broaden my own repertoire. Continue reading

Manzanita, Rock Roses and Friends: The Strength to Stand

Choosing the right plant is not an easy process.  We pick a design theme, make sure our plant choices are a good match for our site conditions, are compatible with their ‘bedmates’ and won’t become overly burdensome, in terms of the maintenance we are able and willing to perform.  There are a lot of variables here.  Our expectations of how a plant performs in the landscape, as individuals and as a composition, are important as we assess their performance over time and decide how we will respond to them.  Many of us are attempting to create gardens that require less of us in terms of maintenance, that fit the conditions on the ground with minimal intervention on our part.  We may chose to create a xeric garden to minimize or even eliminate supplemental irrigation.  If we do, the plant choices we make, their spacing, the size of plants we purchase, even the timing of the planting and the soil prep we do, are all important in our success or failure.  While we attempt to keep our specific site conditions and our goals in mind, we need to be prepared for the extremes of conditions, like weather, that can occur occasionally, even if only once every several years.   Continue reading