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.

This is the species that the Brits selected ‘Childerely’ from, which subspecies…I don’t know.  The only reference I found, from the RHS site, assigned it simply to S. ambigua.  As with most plants provenance will make a difference and there could be considerable difference in hardiness between different provenances as well as subspecies.  I didn’t find any hardiness information specific to subspecies.

It is a very common for native plants, to have their garden worthiness go largely unrecognized, until collectors from other countries, who found them novel, ship them ‘home’ to be grown on where they are often selected and evaluateed, various forms of which may then make it to market, while back home those same plants often languish in obscurity, too often suffering major losses as habitats are otherwise transformed, ‘developed’, used or left to the increasing pressures of invasive plants.  Many local residents and gardeners choose to grow exotics from elsewhere while the market for local natives is small and the growers, collectors and propagators of our native flora, is even smaller.  Local gardeners often ‘discover’ these well travelled and ‘accredited’ plants once they’ve ‘returned’ in the form of cultivars and hybrids at their local garden centers, now with a European pedigree!

As a resident of the American Southwest, this plant evolved in a very different climate than ours in the maritime Pacific Northwest.  It is a true desert plant.  Deserts are generally defined by their minimal precipitation and are limited to areas receiving ten inches or less annually.  Some, in their definition, require that such arid regions also lose at least 10″ of water through evaporative losses as some arctic regions would otherwise qualify as desert going by precipitation alone.  North America’s four true deserts all meet in Arizona, the Sonoran, the Mojave, the Great Basin and the Chihuahuan.  All four have relatively high average annual summer temperatures and very high extremes combined with low humidity.  Moisture in the desert SW is very transitory.  Oregon’s high desert country receives the bulk of its precipitation in the fall through spring.  Like the rest of the NW and the west coast, it shares this  mediterranean pattern.  Sphaeralcea ambigua occurs naturally in parts of Sonoran, Mojave and Great Basin Deserts.

The Sonoran Desert runs as far norther as Central Arizona before it encounters the Mogollon Rim and the abrupt rise to the Colorado Plateau and west into far southeastern California, south of Palm Springs.  It has a monsoonal rain pattern, what it gets tends to fall in and around summer riding the air currents up from Mexico and the Gulf, with less in the winter spilling over the mountains to the west from the Pacific.  The Sonoran Desert is considered sub-tropical, freezes are rare and is then milder than the other parts of S. ambigua’s range.  This species is part of its desert scrub community on dry, rocky slopes, edges of sandy washes, roadsides, and disturbed areas, also occurring in interior chaparral and semi-arid grasslands toward the Sonoran’s margins.  In the Sonoran it is often associated with: Creosote bush (Larrea tridentata), Brittlebush (Encelia spp.), Yucca (Yucca ssp.), Ocotillo (Fouquieria splendens), Paloverde (Parkinsonia spp.), Ironwood (Olneya tesota), and Pinyon pine (Pinus monophylla).

S. ambigua also occupies communities in the colder Mojave where winter freezes are an annual event, its valley floors typically dropping to 25ºF and upland areas getting down to 0ºF and below, its precipitation falling in winter.  The Great Basin Desert, is above the Mogollon Rim, much higher with long winters and consistently colder than the Mojave.  It receives its meager rainfall in winter.   In the Great Basin it is associated with Big Sagebrush and its sister species.  It is interesting to note that other species of Sphaeralcea, but not ambigua can be found in the Chihuahuan Desert east of the Sonoran, is slightly cooler in summer and winter with regular frosts.  The Chihuahuan is more exposed to the cold of the Great Plains sliding down along the eastern face of the Rockies.  This range all suggests that provenance, where your plant comes from, can limit where it will succeed.

In its native region it can be a colonizer of disturbed sites and is often used to help cover bare soil.  It will typically out compete commonly occurring invasive species in the SW…don’t expect that here!  (As is true for any plant that is a local colonizer, care should be taken before introducing it because of its tendency to outcompete less aggressive natives.  This happens here for us when we plant certain of our own native species.)  It is a frequently recommended species for native/xeric landscapes in its region, but even there poor drainage can be a killer.  Irrigation is recommended to extend the bloom season and I would expect that is necessary here with our dry summers, though drainage will be even more important for us.

I don’t know anyone here growing this cultivar or species so I can’t speak to its difficulty here.  Apparently Jimi Blake grows this in his garden in the hills southwest of Dublin, Ireland, where his conditions and climate, mild/maritime, are considerably different than our own.  He has obviously gone to some effort to meet its requirements.  I suspect a gardener will fail if they just plop it down in some random sunny location here without making other accommodations for it.  Other species, other cultivars may be more successful here, but as I’ve said above, these are all denizens of drier regions than ours.

Sphaeralcea munroana

Sphaeralcea munroana ‘Newleaze Coral’ is selection of another American native brought back home to us.  S. munroana can be found regionally in Columbia Plateau country, specifically in eastern Oregon’s Sagebrush Steppe, ranging up into Washington state and southerly through the Great Basin.  Like many species morphological or visual differences can appear very slight between species and S. munroana is commonly confused with S. parvifloraS. munroana occurs more commonly in the northern portion of its range and is a more robust plant while S. parviflora is more frequently is found in the southern portion of it, is smaller and less robust.  Its flowers range from apricot-pink to orange-red.  Being ‘found’ closer to home, with its seasonal rain pattern more similar to ours, though not the annual totals, this plant may be better adapted to our conditions in the Portland area.  ‘Newleaze Coral’ distinguishes itself with its flower color and length of bloom season beginning in early summer and continuing well into the fall in my garden.

Sphaeralcea ‘Newleaze Coral’ another prodigal returned from the UK. This shot, taken in my garden in Fall, shows the typical coral/pink flowers. In the heat of summer they tend toward coral/orange! Interestingly, ‘Newleaze Coral’ was introduced by the Hertfordshire nursery, Hopley’s Plants, just north of London, a clone from a plant found growing in Barbara Barker’s garden, the mother of the nursery’s owner.  The nursery, family operated for 50 years apparently just closed at the end of the 2018 season as the owner’s retired.  Their catalog listed three other Sphaeralcea including Jimi’s favorite ‘Childerley’.  It is a little unclear to me which species this came from as only one source assigned it definitively to a particular species….the others offering only the genus and cultivar names.

It is interesting that this native of the arid and semi-arid west, the Intermountain West and Great Basin, also had to be adopted first in a country known for its maritime, dank climate, a place not exactly conducive to these plants.  Gardeners everywhere seem to rise to a challenge.  When we wet-siders attempt to grow these same plants we should pay attention to the methods utilized in the UK.  I’ve seen garden bloggers describe growing this species in the summer wet US in sand filled troughs and in well drained pots in England.  While our summers are dry, much like the native home range of this species, we should take careful note of the fact that our soils and winter wet can prove fatal to these and other east-siders.  It will not be our cold that kills these.  Soil drainage can become the single most important factor in their survival.  While they seem somewhat tolerant of summer irrigation, though I would go light on it, these are denizens of generally coarser, drier and poorer mineral soils than we have on the west side though in other semi-arid areas it can grow in clay soils.  Plants from such areas can, paradoxically, suffer from our too rich soils which can lead to an increased growth rate, which can weaken the plant.  We should also note the composition and structure of their native plant communities.

[Check out the plant list for the John Day Fossil Beds National Monument and then go there this spring!  See the plant growing in its native range in one of its common plant communities!]

The Columbia Plateau and Great Basin include much Steppe country, both Sagebrush and Grass Steppe.  These areas share common conditions in terms of both their climates and plant communities with those of the Earth’s other Steppe regions which include vast areas within Central Asia into Eastern Europe, the Western Cape of South Africa, the plains of Patagonia and Argentina and much of our Intermountain West and Great Plains country. (Steppes: The Plants and Ecology of the World’s Semi-arid Regions, By Michael Bone, Dan Johnson, Panayoti Kelaidis, Mike Kintgen, and Larry G. Vickerman, Timber Press, is a great and easily readable overview of these regions and helpful in understanding their shared requirements.) All of these are linked by their continental climates, with pronounced seasonality, arid and often wide daily temperature swings.  They are generally too dry to support forests and woodlands, but slightly ‘wetter’ than desert climates.

This is a screen capture from Wildflower Search showing locations of where Sphaeralcea munroana have been observed in the field. This is a very handy site with many links for good photographs as well as to regional herbaria.  The site can be searched using wide ranging criteria from very specific locations to flowering dates.  You can look for specific plants or plant communities in a particular area.

The northern portion of this species’ range, the Columbia Plateau, tends to be ‘wetter’ averaging up to 15″ of rain annually which technically puts it out side of the range of true desert.  The broad open landscapes and canyon’s of this country, in its non-cultivated areas, is being gradually taken over by Juniper Forest as fire has been eliminated from its normal long cycle.  Around its edges is where you find Ponderosa Pine.  Keep in mind that the Oregon High Desert is a common appellation and it’s a ‘desert’ only because of its relative dryness when compared to the wetter west side.  The Redmond area rides the edge in between receiving around 10″.   Precipitation generally decreases as you move south easterly, into Oregon’s Great Basin country, increasing again, somewhat in the region’s mountains.  Areas like the Hampton Valley include large natural grasslands.  Patches of true desert, like the Alvord, generally receives less than 7″ of rain annually.  Vegetative cover of arid and semi-arid regions are less layered with the sun striking much, if not all, of the ground layer of plants so they are sun adapted with specialists that occupy shady areas.  Plants like the Sphaeralcea spp. will ‘want’ full sun exposure.

This picture of Sagebrush Steppe was taken near Vantage, WA. Sphaeralcea spp. don’t ever dominate the natural landscape, they are a component species in the community. Collectors select from often massive landscapes plants or seed of particular plants with those characteristics they want to reproduce. From the progeny that follow individual plants may be chosen, individuals with unique or notable characteristics. We select little plant jewels to place in our gardens because they please us, often with little understanding of the landscapes and forces that have long supported them, losing the ’emotional’ impacts and weight of those landscapes…and the life that animates them.  Sagebrush communities like this cover many thousands of acres in the intermountain west.

Most areas in the Willamette Valley due to their soil and grade will require considerable effort to meet Sphaeralcea spp. needs.  In the Portland area as you move north and east toward the Columbia River Gorge the soils become somewhat coarser and contain a proportion of rock of increasing diameters which improve overall drainage.  This is due to the historic massive floods that scoured out the gorge, larger sediments and rock settling out as the floods spread out and slowed as they entered the valley.  As the floods neared where the Willamette now runs what was left to settle was very fine.  The floods swept up through the Willamette Valley depositing the fine soil it carried covering the bottom in thick layers, ‘flattening’ the valley between the two ranges.  The accumulative effect of these many floods determined our soils.

For most of us here there will be changes and siting questions that are essential.  Plant high, raise their crowns above the surrounding area, plant them on quicker draining south facing slopes, create a crevice or ‘alpine’ garden with rockier soils, use them on the dry south side of structures with overhanging eaves, put them in south facing Hell Strips and plant them with other plants with the same requirements…don’t crowd them!  Be stingy with summer irrigation and likewise with fertilizers and organic mulches.  Recall that our soils are already more moisture retentive and that organic mulches can retain moisture around the sensitive ‘collar’ area of plants increasing the likelihood of rot…bare soil or a mulch of gravel would be preferable.  Plants of the Steppe often grow as individuals with separation, space, between them.  Their soils are not simply ‘bare soil’.  The open space between them form biological soil crusts, cryptogramic ‘living crusts’, held together by micro-organisms, fragile structures, that perform important ecological roles including carbon fixation, nitrogen fixation, soil stabilization, alter soil albedo and water relations, and affect germination and nutrient levels of the vascular plants in their communities. Such soil crusts can be damaged by fire, recreational activity, grazing, and other disturbance and can require long time periods to recover their structure, composition and function. Native soils are never just dirt!  The openness of their native plant communities not only reduces competition for limited moisture but also drop the humidity in and around them.  Don’t crowd these plants.

If you provide your site with better drainage, if it is not underlaid with a dense, compact, layer which effectively slows or prevents percolation down, many urban sites here on the wet west side of the state, can better provide what these and other plants from Steppe communities require.  On some specialized landscapes similar native conditions exist here already and have for centuries.  Throughout the Willamette Valley are many scattered basalt outcroppings, hills, with thin soils that support very different native plant communities than the broad open and often wet prairies that once dominated the valley.  The Portland area itself contained these on Rocky Butte and elsewhere, though the area was dominated by mixed Doug Fir and Deciduous communities away from the creek bottoms and Willamette River itself, above the flood plain.  These thin skinned and spare landscapes could still have a home here and the conditions that support them are more prevalent today with the intensity of urbanization.  This is a radically altered place.  The process of urbanization and the destruction of the original plant communities here, the elimination of the tree canopy, has increased the summer heat via the built, reflective and radiant hard surfaces and the reduction in organic content of our soil.  These changes would seem to be more supportive of plants like Sphaeralcea and others raised on a more ‘spartan diet’.

The loss of organic content in our soil here came along with the removal of the native plant community.  The city’s entire landscape has been reworked, soils upended and graded to support development.  The growth of our original plant communities, their extensive root systems, that once continuously cycled high nutrient levels, capturing and releasing it as roots and leaves are sloughed off and replaced, is long stopped on most sites.  Steppe communities are less diverse, perhaps less complex, less organically dense due to their reduced biomass, their extreme climates and soils.  Urbanization has transformed our landscapes in ways less directly visible to the casual observer, but changed they are and it is not just the absence of the top growth of the original communities.  Conditions common to our urban areas today are very different than they were before the landscape’s massive transformation.

Closeup of the bright flowers of Sphaeralcea munroana, a plant I found growing along the Deschutes River in Tumalo State Park, just north of Bend, OR where the narrow canyon opened up in the Park.

Sphaeralcea munroana, and other species of the genera, are often classed as seral, they are generally members of transitional plant communities, members of communities on their way toward becoming.  Once disturbed sites must build back the communities that occupy them above and below the soil.  Each species requires or benefits from the presence of other species.  Each species, each individual, modifies the environment influencing what niches are available, what species have a competitive advantage to establish.  Seral plants are important to this natural development on a site beyond just holding the soil.  In their native communities they provide pollen and nectar for multiple native ground nesting bees and butterflies as well as browse for ungulates.  Will Sphaerlacea spp. ever serve this role here as transformers…probably not, even with urbanization and climate change, but there is no reason that we cannot enjoy and learn from them.  We as people often have a hard time comprehending the complex nature of plant communities and the essential roles their members fill.  Native plant communities rely on these relationships.  There are no annual additions of compost, mulch or fertilizers, no supplemental water to get members through tough drought periods, no one to replant when a member is lost or to remove an overly aggressive competitor.  The system is closed and reliant upon the elements….But, it is also supported within through an incredibly intricate and complex system of feedback loops.  When I plant out my Sphaeralcea, or any plant for that matter, these quite intimate relationships are largely absent, unless we work carefully to build them, or something like them, back.

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Other Species, References and a few sources

Sphaeralcea philippiana is a low sprawling plant from Argentina, another one of the world’s steppe regions, growing as much as 2′ high in mats with lax stems, 5′-6′ across, typically with pinker flowers.  It is a very different plant though it too is drought tolerant.  I’ve seen it offered by California Gardens.   Native Sons offers it as a zn 9a plant, hardy 20ºF.  The latter’s listing is a little confusing as they say it is synonymous with S. munroana?  I found no other botanical database that listed these as synonyms.

Sphaeralcea munroana, the species, can be found at a variety of western nurseries.  High Country Gardens carries it for mail order customers.  Be aware that when we buy from nurseries elsewhere that they describe a plants needs in terms of their own local conditions, so when High Country says that it thrives in heavy clay, that is for them with their more limited precipitation.  Drainage will be central to its survival in areas like the Willamette Valley.  Forest Farm has carried this in the past.
Las Pilitas also offers the species in Santa Margarita, CA.  Winter Creek Nursery, in Bend, OR, is a great source for Columbia Plateau and Great Basin natives of eastern Oregon.  Check out their latest availability list.  Clearwater Native Plant Nursery outside Redmond, Or, grows both S. munroana and S. grossulariflora wholesale.  Better eastside garden centers may stock these for their retail customers.  There are likely other smaller native nurseries that carry a variety of these species as well.

Sphaeralcea grossulariflora, is probably the most cold hardy, allegedly down into the bone chilling places that experience USDA zn 3a!  Native west of the Rockies north into Canada, south to Mexico, on exposed dry sites, often above 3,000′ to ‘6,600, with orange-red flowers.  In Utah, where it is most common, it can grow in relatively dense stands on basic, non-acid, soils with high salts.  Check out the pdf that the BLM has put together for this species.  In Oregon it tends to occur in the drier southeast corner, these relatively extreme environments suggests that this may be a little more difficult here in the Willamette Valley.

A pinker form of Sphaeralcea coccinea

Check out the red flowering Sphaeralcea coccinea carried by Dancing Oaks and Winter Creek hardy down to USDA zn 5a.  It’s native to much of the western US, extending out east from the Rockies into the near plains country, flowering abundantly in orange/pink.  In Oregon it is primarily a Great Basin plant though it occurs in John Day River country.  It has not been found in eastern Washington.  It is very similar in appearance to Sphaeralcea munroana, but smaller in stature.  Both S. grossulariflora and S. coccinea can be spreading, groundcover plants where the others discussed here are all upright growers with tight crowns.

Secret Gardens in the Canby area, suggests growing Sphaeralcea incana for those of us in the Willamette Valley who have trouble growing S. ambigua.  They claim that S. incana is somewhat more tolerant of winter wet though you still must pay attention to siting and winter wet soils.  I don’t have any experience with this one.  It is another SW US plant hailing from Arizona and New Mexico to central Texas where it grows to heights between 3 to 6 feet on grassy-rock slopes, in sandy soils, among boulders and on gravely-clay flats in the Trans-Pecos, that area of far west Texas, west of the Pecos River to the Rio Grande.  Secret Gardens claims a more modest 2′-3′ for its height.  Seeing pictures of the Big Bend area its a little hard to imagine that these would do better here, but nature is full of surprises.

Big Bend National Park and the Chihuahuan Desert.  from wikipedia.  This landscape is very reminiscent of Great Basin desert and steppe landscapes.

Sphaeralcea ‘Newleaze Coral’ is offered by Cistus Nursery here in Portland.  Owner and plantsman, Sean Hogan, says this is a hybrid hardy into USDA zn 6 or 7.  Often cultivars arise spontaneously in garden and nursery settings between promiscuous partners and it is not always possible to say definitively, which are the parents and so growers leave the name reduced to genus and cultivar.
Paul and Greg at Xera also grow and offer ‘Newleaze Coral’ here locally in Portland.  Wholesalers Suncrest Nursery and Native Sons in California grow it as well.
It is interesting to note that the UK selected ‘Newleaze Coral’ is offered by 13 different growers there and S. ambigua ‘Childerly’ is carried by ten different suppliers according to the RHS plant finder.  I found  S. ambigua ‘Childerly’ at retailer Dancing Oaks here the Willamette Valley and at wholesaler Native Sons in California and no where else!  One must still look for these ‘natives’ here!

As a go to site for Western wildflowers I often first visit Wildflower Search.  The site gets ‘richer’ every year as they continue to add more data points and links to herbarium and exceptional photo libraries.  In this case they list 17 species of Sphaeralcea with links to specific locations within their range, flowering dates, elevation, habitat type and more…a great site.

Curious about the Sonoran Desert, then check out the Sonoran Desert Museum’s site.  They are located outside Tucson and do extensive work in both research and education.  Their site is very informative.

Want to learn more about Oregon’s High Desert country check out the activities and work of the Oregon Natural Desert Association and visit the High Desert Museum south of Bend.  You can also work in a visit to the John Day Fossil Beds National Monument to see the wildflower display in April-May or visit the Thomas Condon Paleontology and Visitor Center and check out the National Monument’s extensive plant list.

Looking for more S. munroana growing information, check the USDA plant guide site.  The USDA has other plant guide pages for several of the other species as well as many more for important species across the US.  In addition these guides include zoomable maps of the US for each listed plant showing in which counties they have been found.

Screen capture of a section of the NRCS Plants Database map for Sphaeralcea coccinea from the above USDA site above showing the counties in which this species has been found growing in situ.  I have not found a site like CalFlora which shows where each plant has been specifically collected from for herbaria use for the PNW.

 

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2 thoughts on “Growing and Understanding Globe Mallows in the Urbanized Maritime NW: Sphaeralcea spp. and Cultivars

  1. MulchMaid

    I like Sphaeralcea and have S. ‘Newleaze Coral’ in my garden. It has always interested me how England seems to embrace some of our natives with open arms; I first saw Ceanothus grown in my aunt’s garden in the Thames Valley in 1970!

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  2. Will

    I always appreciate all of the details you provide. It’s very helpful to a fellow Portlander. I planted a Sphaeralcea ‘Hot Pink’ from Xera early last year, and it was definitely the star of my front yard. Seems to be doing very well so far, just stopped blooming and no defoliation.

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