Fraxinus americana 'Autumn Purple' (White Ash)</p> "Disaster in slow motion" is a phrase that has been applied to many phenomena including global warming, the collapse of biodiversity, chronic drought...and most recently it's been appled to the Emerald Ash Borer (Agrilus planipennis</em>: henceforward referred to as "EAB") a green beetle from East Asia that was introduced accidentally in wood pallets in Detroit fifteen years ago. Since that time it has infested billions of ash trees in twelve states. The cost for removing dead ash from the urban forests of America is already climbing into the millions for even small cities, and the concomitant issues: thinning of the urban canopy, storm water abatement, air quality--these costs are hidden but real. No wonder when EAB was confirmed in Boulder only twelve weeks ago, arborists and decision makers across Colorado practically panicked. Ashes comprise around 15% of the trees in Colorado's cities: the cost for removing and replacing these trees over a short period of time is truly astronomical and daunting.</p> On Tuesday of this week, several of our staff joined hundreds of arborists from across the state and beyond at a daylong Emerald Ash Borer Management Seminar sponsored by Denver Parks and Recreation, the State Forest Service and Davey Tree. Several local authorities as well as those from some of the first areas affected by EAB gave very informative presentations that helped dispel some of the panic and provide some clear options. Several points that emerged were that because of Colorado's compartmentalization into different river drainages, the progress of the insect will likewise be compartmentalized. Since enough cities are separated by open space where ashes are not present, the progress may likewise be slower. A multiplicity of factors are showing that there are viable options for preserving many ashes with timely insecticidal treatments, and that a coordinated effort could preserve many ashes for a long time--rather along the lines of the strategy pursued with American elms--many fine specimens of which are still standing throughout our region despite the fungal infestation that destroyed nearly all of the elms in parts of the East.</p> Although there are compelling ecological and economic reasons to deplore this latest threat to our horticultural legacy--I came out of the meeting somewhat heartened by knowing so many professionals and decision makers cared, and that there were some practical strategies that will mitigate if not forestall this impending "disaster in slow motion". This link to a paper by Dr. Daniel Herms, Professor at Ohio State University at Wooster</a>, gives a good summary of the methods that will likely be used to preserve many--alhough by no means all--of the tens of thousands of ashes that grace Denver and the Front Range.</p> Ashes to ashes--but not yet quite to dust!</p>
Young Siberian larch (Larix sibirica</em>)</p> You have probably walked by this willowy sapling many times--although I suspect if it were not in fall color, you would have walked by it barely noticing it! There is another specimen or two of Siberian larch at the Gardens. This one is west of the Western moongate just outside PlantAsia. If you're a tree fancier, you might linger for a moment and think, "A larch from Siberia--I suppose there are larches there." As botanic gardens mature they often focus more and more on recondite research issues, or more global conservation concerns almost forgetting what most people expect. Visitors who come are usually curious about plants. How wonderful it would be if they would realize that the modest specimen at the Gardens often represents a major plant where it comes from. So it is with this larch which covers literally millions of acres across the breadth of Asia.</p> Enormous mature larch in the Altai Mountains</p> Here you can see what heights Siberian larch is capable of attaining in the wild! I was very fortunate to have had Plant Select underwrite a trip that Mike Bone and I took to Central Asia in 2009. One of the many highlights was seeing thousands of enormous Siberian larch everywhere in both Kazakhstan and Mongolia. Unlike our native tamaracks in both New England and the Pacific Northwest and Alaska, their Siberian cousins often grew on steep, sunny slopes rather than wet streamsides and bogs. They formed open forests all the way to dry treeline, but could be found also isolated on surprisingly dry areas in the higher steppe, growing among sparse grasses and sage. This specimen was enormous.</p> ! Siberial larch alongside explorers</p> Here you can see Mike Bone on the right with our guide Vladimir Kolbintsev, leaning on that same giant tree. I doubt I will be around to see the saplings planted at Denver BotanicGardens attain half this size and girth--but it would be fun to do so!</p> Rugged larch on the Austrian road</p> When we finally reached the summit of what they call the "Austrian Road" in the Kazakhstan Altai (built by Austrian prisoners of war) we saw a rugged tree in the distance we decided to investigate...</p> Giant Siberian larch on summit of pass</p> We could scarcely believe our eyes as we approached--this one had even greater girth, and the most rugged habit. We could see the highest peak in Siberia (Mt. Belukha) from the pass. Not far away (near the very heart of Asia, equidistant from Indian, Arctic, Atlantic and Pacific oceans), this area experiences unbelievable cold in the winter, and the winds on this alpine summit must be hurricane in force for months on end. And yet here it grew, almost solitary, as picturesque as an ancient oak in Windsor Great Park.</p> Larch cones</p> The needles are so fine and soft, the cones are so delicate that they belie what must be ironclad toughness in the tree itself. I have always felt that larches would be a wonderful addition to Denver's parks and streetscapes because of their airy look and toughness. Siberian larch I fancy would be the best choice, although I know of almost no commercial sources. Unfortunately, our local landscape contractors aren't familiar with larches. I know of several instances where larches have been removed in winter because it was supposed that they have died when their needles fell. It would take quite a campaign to educate our local populace about them. But I think it's worth doing!</p> Larch cones</p> Another glimpse of the nearly golden cones in the late summer. Makes you want to look inside them!</p> Our larch near PlantAsia</p> We end where we began, with our still very modest larch. Seeing the venerable specimens in Kazakhstan, one can appreciate how these might one day grow to be massive and imposing. More to the point, perhaps, one is humbled to realize that every one of the tens and thousands of accessions of plants at Denver Botanic Gardens has a compelling story much like this one. The world of plants is infinite!</p>
Asian dogwood (Cornus kousa</em>)</p> "Asian dogwood? Surely photographed in Oregon, or perhaps New Jersey?" Nope--taken at Denver Botanic Gardens last June. There are several specimens--this one in the Rock Alpine Garden, but also at Waring House that reliably bloom late every spring.</p> Cornus kousa</em> tree in Rock Alpine Garden</p> You are not apt to find many dogwoods elsewhere in Denver--but staff at the Gardens are fond of "pushing the limits" and trying plants that are generally considered marginal, or unsuited to our windy, steppe climate. Time and again we succeed!</p> ]Engelmann's cactus (Opuntia engelmannii</em>)</p> "Surely this picture was taken in Arizona? Mexico?"--a big bushy prickily pear loaded with fruit?Taken at the Watersmart garden where this clump is easily a yard high and twice that across!</p> Bull Bay (Magnolia grandiflora</em>)</p> "This tropical looking magnolia must have been photographed in Mississippi? Or California? Surely these evergreen magnolias can't possibly be hardy in Denver?": there is, in fact, a comparatively huge specimen in the courtyard of a public school in Jefferson County--but you can find several of these all around Denver Botanic Gardens. This one bloomed beautifully in July in the Victorian Secret Garden (it would have been nice to have one of those models nearby to pose with it?)</p> Dragon Arum (Dracunculus vulgaris)</p> "This huge-flowered black aroid must be from some Subtropical country? Turkey perhaps?" No, Virginia--the black arum in the Rock Alpine Garden where this is self-sowing. Here it is very hardy indeed and seems to love growing in Colorado. You won't want to linger around these clumps when they're in bloom, however: the smell is pretty strong!</p> Texas Agave (Agave havardiana)</p> "And this huge Century Plant? It must be from the Davis Mountains of Texas?" That may be where the seed came from originally, but this hefty specimen--over a yard across--is in the Watersmart Garden in front of the Conservatory--and may well bloom in a year or two!</p> Drakensberg gladiolus (Gladiolus saundersii</em>)</p> "And this African Gladiolus--are you telling me this is hardy too?" Coming as it does from the highest Drakensberg it should not be surprised that this beautiful gladiolus is root hardy in Colorado--despite its exotic looks.</p> Giant Sequoia (Sequoiadendron</em>) in south Metro area</p> Not many Denverites would believe that there are giant sequoias around the city: Denver Botanic Gardens is not the only entity that "pushes the limits" around here--lots of private gardeners do too. Here a number of the staff who are keen on trees recently visited what may be the largest in the immediate Metro area, although the State Champion is in Grand Junction. We have a whole grove of these in the Gates Garden that are approaching this one in size. Despite many sub-zero winters, these seem to show no winter damage.</p> Crevice garden</p> "Surely this picture was taken on Mt. Evans? Such a natural outcrop has to be in the hills, right?" Wrong again--this is one of a half dozen wonderful crevice gardens that have been built in the Rock Alpine Garden and Children's Gardens the last two years which are one of the best ways of growing tricky alpine plants.</p> All these exotic plants and garden styles are examples of how gardeners seek to "push limits" and grow what they perhaps shouldn't try to. Of course, a Botanic Garden is the logical place to do this experimentation since we have the room and knowledgeable staff to study up on plant needs.These exotic plants offer a great contrast to the more extensive collections of native and adapted xeric plants we are so famous for showcasing. Nevertheless, time and again we have been shocked at how well "marginal" plants perform--sometimes better than "tough" natives! Almost three decades ago staff planted Hesperaloe parviflora on the site of what was to become the Watersmart Garden: I remember scoffing as I walked by "Surely this plant from southern Texas doens't have a hope here"...within a few years it proved its mettle, and now there are thousands thriving all over the Metro area--all because we pushed some limits at the Gardens! </p> </p>
Scott Skogerboe and mystery maple...</p> Everyone should have a hero. Scott Skogerboe has always been one of mine: Head of propagation at Fort Collins Nursery Wholesale</a>, he and his boss, Gary Epstein have been the force behind most of the woody plant introductions of Plant Select</a>. Here he is standing in front of...well...you shall have to wait and see (I have my crafty ways of making you read all the way to the bottom of my blog posting!)....</p> Amur maple at Box Store</p> This is NOT the same maple as the one with Scott above--this is an Amur Maple (Acer ginnala</em>) I photographed today (October 20) on West Colfax in front of a Box Store which I am NOT</em> endorsing (although I confess I did</strong> by 50 of awesome plants while I was there...). As the name suggests, Amur maples originate in the Amur river region of East Asia, the river that separates Manchuria from Siberia. No wonder the tree is so cold hardy! But that area is also Maritime--and the soils are podzoils: generally acid, more like the soils of our upper Midwest and New England. So of course, Amur maples in Denver are frequently chlorotic, and usually not recommended by horticulturists "in the know". No one bothered to tell the landscape architects, who filled the vast parking lot of this box store with them--and each and every one of them are blazing in DIFFERENT colors, and looking mighty healthy!</p> A whole ROW of frickin' amurs</p> Here you can see bits and pieces of a half dozen Amur maples in blazing color---looked like a regular conflagration! Each was robust, and each a very different shade of flaming red and orange (and some yellow and one or two green--this picture doesn't show them quite right--I'll show some closeups to better demonstrate a wonderful quality that is being increasingly denied people: namely, the wonderful biodiversity and variability that comes with seed grown plants.</p> Yellow-orange Amur</p> Although most of these maples were an unalloyed scarlet-vermilion, one was more orange-yellow in tint...</p> Green leafed Amur</p> Right alongside all the red ones, one had barely begun to turn and was still mostly green</p> Bright vermilion Amur Maple</p> But of the several dozen Amur maples around the parking lot, most were this flagrant, bracing, wonderful red color that we all love so much in the species. I have seen dozens of Amur maples all around Denver looking this good--there are some massive ones near Denver Botanic Gardens (and I have a pretty awesome specimen in my own garden too--hee hee)...but for every stunning Amur maple, there are usually a few gnarly, miserable things that look awful year around and hardly color up in fall. I have a hunch some of these are simply inferior plants, and others are probably growing in particularly bad sites with more alkaline soils, perhaps, or other environmental problems...Here, you should generate a drum roll and have the summon the cavalry with trumpets! Woo hooo!</p> Acer tataricum</em> at Fort Collins Nursery Wholesale</p> Last Friday, while visiting Scott at Fort Collins Nursery Wholesale, I espied a furiously red small tree in the distance--the same one pictured at the beginning of this posting with Scott standing in front. This is a superb, red-fall coloring Tatarian Maple--a sib to the Plant Select Introduction, Acer tataricum</em> Hot WingsTM</a>. I have observed around town that Hot Wings Maple has been quite reliable about turning a wonderful reddish purple color in most sites. And since it is a selection of Acer tataricum, it will thrive in far more alkaline pedocal soils ("Tatarian" refers to "Tatary"--the archaic term used for "Turkestan", the designation for the portions of Czarist Russia in Central Asia--namely contemporary Kazakhstan, Kirghistan, Uzbekistan and the smaller neighboring "stans" that are now mostly independent states, but formerly parts of Russia and the Soviet Union. Mike Bone and I found Acer tataricum</em> several times in Kazakhstan--many of them with the bright red samaras much like the Plant Select clone...</p> And here's the rub--you can go to almost any nursery in Colorado (in fact around the United States, Canada and Europe as well) and find Hot Wings in several convenient sizes--which you can purchase and plant in your garden and get not only spectacular fall color, but a shapely small tree the rest of the year which has brilliant red fruits for much of the summer--which look as bright and dazzling as flowers for an extended period: it is apt to thrive for you on acid or alkaline soils, and once established in Colorado thrives with almost no supplemental irrigation: what's not to love?</p> One of the great ironies of Colorado horticulture is that the ultimate seedsman (Scott Skogerboe) has also developed a number of clonal plants that will one day greatly outnumber the millions of seedlings he has grown in streetscapes and gardens around the world. Such are the ironies of our crazy modern world.</p> A piece of me wishes we could have developed a seed strain of red-winged maples so we could enjoy the wonderful biodiversity that thrilled me earlier today at Home Depot as I wandered through the Amur maples (imagining what they must look like in their native habitat right now, with the last few Siberian Tigers slinking through them nearby)--wait! What was that orange flash I caught out of the corner of my eye!? For a brief second I felt like Derzu Uzala</a> (you must rent this dazzling Kurosawa classic if you've not seen it yet) and a moist Siberian breeze caressed my cheek.</p>
Random sampling of Burr Oak Leaves</p> Our spring may have been the worst I can ever remember, but fall is shaping up to be extraordinary. Yesterday, towards the end of the amazing Pumpkin Festival at Chatfield I found myself wandering through the extensive windbreaks, most of which were planted twenty or more years ago by my friend Chris Hartung, who now runs an amazing nursery in Canyon City</a> with his wife, Tammy. It would be fun to walk the windbreaks with Chris and hear his stories: the trees have grown surprisingly well despite no irrigation, abundant bunnies, deer, elk and you name it in the way of herbivores. Even the "slow growing oaks" are getting some size despite the lack of irrigation! Burr Oaks (Quercus macrocarpa</em>) do not color brilliantly as most trees do in Denver: but they make up in rugged charm and wonderful leaf shape and acorn what they may lack in brilliance! Just look at the amazing variabillity in leaf color and shape in this very random sampling!</p> Burr Oaks at Chatfield</p> Denver Botanic Gardens at Chatfield is truly stunning: although the plant collections are still modest (the Visitor Center Garden--designed by Lauren and Scott Ogden, is world class, however, and large nevertheless), what makes a visit to Chatfield so gratifying right now are the wonderful vistas! The Rockies looming all along the West, the gently rolling countryside: it is our Secret Garden (although the tens of thousands of people coming to pick their pumpkins yesterday must have had an inkling! There were record crowds this year!)</p> Windrow of Burr Oaks: each one different!</p> It's great fun to stroll the windrows: every plant looks different. Some have already lost all their leaves, a few are still bright green. I wonder where the acorns were collected for these: are they from the Midwest? Or did Chris find a source from the wonderful Burrs that grow around Devil's Tower in Wyoming. On a recent visit to Gillette in early spring a few years ago, my hosts drove me up to the Devil's Tower and we walked around it (clockwise--the way you should walk around mountains of course!). This is the Westernmost colony of the tree in the northern Plains, and they were almost exactly intermediate between Gambel's and Midwestern Burr in character--some even stooling like a Gambels. The ones at Chatfield look more treeform (although still only fifteen or twenty feet tall at the max). I planted two burr oaks at my house about the same time Chris planted these and my Burrs are enormous now--one has to be over 30' tall and almost as wide and starting to take on the rugged adult form: three or four times the size and girth of these specimens: such is the power of irrigation!</p> Burr oak acorn</p> There were not a lot of acorns (the trees are yet young) and the ones I found were much smaller than the golf ball sized burr oak acorns I used to marvel at as a child in the park next to my house: those more than justified the common name "mossy cup" or "overcup oak".</p> An example of variability</p> This shows how variable the trees are: the one on the right was still mostly green, the one on the left is all brown and in the distance the burr oak is totally naked. All in proximity with what must be very comparable soil and exposure. Go figure!</p> Sprig of oak</p> For tree lovers, oaks and pines have a special resonance. If you've ever been lucky enough to see the massive burr oaks throughout the Midwest--all the way to the East Coast actually. Although I associate them especially with the magnificent oak savannahs around the Great Lakes and the rolling hills of the upper MIdwest. From a distance the white oak (Quercus alba) and burr oak look somewhat similar--but closeup the leaves and acorns are immediately distinguishable. Right now the handful of white oaks in Denver are a blazing, furious scarlet color (well worth their own blog!)--but even despite their superior fall color, it's the burr oak one finds here and there throughout our fair city. I believe the State Champion is just west of Cheesman Park--a massive creature that fills all the neighbors yards with leaves...(I know one of those neighbors and she's not to crazy about that tree)...</p> What sets this oak apart from many of Denver's street trees is its obvious drought tolerance. Chatfield's vast strings of windbreaks (so lovingly planted and cared for by Chris for years) are coming into their own: they make Chatfield a friendlier, more inviting place.. and they are teaching us a lot about the adaptability and variability of plants we should be planting more: the survivors!</p>
</p> Allium</em> 'Millenium'</p> Diane Reavis, one of our long time Plant Select committee members, observed that "we don't do a lot with the summer Alliums at Denver Botanic Gardens" as the committee strolled through the Gardens the other day. That got me thinking: I used to grow lots of Allium ramosum</em> in the Rock Alpine Garden, and I know there are some wonderful forms of Allium cepa</em> that bloom right about now. But with the notable exception of this spectacular clump of Allium</em> 'Millenium' in the middle of the Water-Smart garden, we really don't have very many right now.</p> Since this has been an area of great hybridization in Europe and the East, I have a hunch our staff will incorporate far more in coming years. You can probably guess what year Mark McDonough--who hybridized this showy beast--introduced it in? It has Allium glaucum</em> ancestry, and probably some A. ramosum</em> as well. I love the way it contrasts with the Devil's Shoestrings behind it (Nolina lindheimeri</em>).</p> </p> Allium senescens</em> v. glaucum</em></p> Here is one of the parents growing in my private garden. It was taken a few years ago this is only now starting to bud up and won't be in full bloom for several weeks. These form dense tufts of swirly foliage that look like a vortex, decorative in its own right. Thrives in almost any sunny, well drained spot. I've even had it over-winter in containers!</p> </p> Allium cernuum</em></p> One of the best late onions, however, is our native nodding onion, which you might encounter almost anywhere in our mountains below treeline. In fact, it grows pretty much across the United States from coast to coast. It is enormously variable in habit, size and flower color. It's worth trying this from various populations--you will find quite a bit of variation. This one was photographed in the Rock Alpine Garden.</p>
Yucca rostrata in Yuccarama</p> There are certain floral spectacles through the gardening year at Denver Botanic Gardens that are not to be missed: when the foxtail lilies (Eremurus</em>) are all in bloom early in June, for instance, or the Iris beds much of May and June... Well, right now we have the time of Yucca blossoming--and they are truly amazing any time of day--although they seem to glow with a special luminosity in the late afternoon. Yucca rostrata</em> may be primarily Mexican in distribution, but there are many robust and happy specimens blooming right now throughout the Gardens. I believe this my favorite!</p> Forest of tree yuccas</p> Ann Frazier, a volunteer, recently scanned this historical photo, showing the largest tree yuccas at the gardens a year or two after they were planted in the late 1990's. I blogged about these recently</a>...but it's worth revisiting these now that the flowering season is here...</p> Same yuccas taken today, July 2, 2013!</p> Do look back at the previous picture and see how dramatically these have grown in the last decade: I never cease to be amazed that Chihuahuan desert plants growing over 1000 kilometers south of here at lower elevations have the genetic tolerance to our severe winters! These have shown less frost damage than some of our native plants over that time! These were donated to us by Mountain States Nursery for testing and display, and I recall as Dan Johnson placed these thinking they would be the most expensive annuals we ever planted! I was wrong, obviously....By the way, the largest yucca in this planting is Yucca faxoniana</em>, and the more slender ones are Yucca thompsoniana</em>--both from the Chihuahuan desert in Texas and Mexico with roughly the same range as Yucca rostrata</em>.</p> Denver Botanic Gardens has a remarkable collection of many dozens of accessions of cold hardy yuccas that are located in many of our gardens. Now is a wonderful time to look at these--I have discussed a few of them in yet another one of my blogs you can find by clicking here.</a> And another one here</a>! As you might have guessed, I like yuccas! I end my little disquisition with a tribute to our ubiquitous, overlooked and sometimes maligned Yucca glauca</em>: Last May I drove through vast forests of this species in the Oklahoma panhandle and was dazzled by their heavy blossoming. Among the mostly creamy or ivory flower stalks were many that were stained quite deep pink. It was a dream of Claude Barr's to find a truly red yucca: I think these are well along the way to that goal! Alas, I was unable to collect that trip--so perhaps you can be the one to locate and introduce that holy grail?</p> Red stained Yucca glauca in Oklahoma panhandle</p>
Succulent sculptures at entrance to cactus and succulent greenhouse, Gothenburg botanic garden. The Swedes have a great sense of humor. I have been lucky to visit many of the world's great gardens: I shall never forget an April visit to Savill Gardens: millions of daffodils in bloom and me (just like Wordsworth's poem!). Royal botanic gardens Edinburgh on a perfect spring day. And I have now visited Gothenburg botanic garden again--after nearly 20 years absence. Many of my plant addicted friends agree with me that this may have the finest collections of Temperate plants on earth, grown to perfection and displayed with great artistry. Gothenburg ROCKS! And I'm here at the perfect time for their mind boggling bulb displays...a tiny fraction of which I shall share here with you... Anemone nemorosa coming into full bloom in woods all over Sweden: floral symbol of Gothenburg botanic garden...(sublime!) Before I do that I thought I should show you the wood anemone that is blooming by the million everywhere in Sweden right now: these were taken at Gothenburg: this is the floral symbol of that garden. Not bad, eh? I think Denver Botanic Garden should have a floral symbol...the Pasqueflower, perhaps? Easter daisy? Let's hope we pick as wisely! Carl Skottsberg, first director of Gothenburg Botanic Garden: a great botanist and visionary leader Gothenburg has had more than its share of brilliant leaders, starting with the first (who is honored on this medallion in the administrative building). Per Wendelbo, who led the garden in the middle of the last Century, is credited for really elevating its collections and stature--he was Norwegian by birth, and died tragically in a traffic accident in middle age. He picked out Henrik Zetterlund as horticulturist, who has been the guiding spirit of the garden ever since--and whom I will honor in my next blog--showing him in his native habitat in Götene where he has a weekend home.... Tanacetum leontopodium, a wooly composite from alpine heights in Central Asia--one of thousands of fabulous plants blooming right now at Gothenburg An alpine daisy, challenging to grow outdoors in Sweden, grown to perfection in one of the many alpine houses. Mats Havström, curator of Herbaceous collections took Sunday off to show us around behind the scenes: one of many young talents who are maintaining the momentum of Per Wendelbo's dream. One of the many talented young staff in the Dionysia house, showing a group of us around last weekend. Iris linifolia, a rare Central Asian Juno iris grown to perfection in one of the bulb greenhouses ("behind the scenes"). I doubt you would find a FRACTION of the plants in this botanic gardens' collections anywhere in America--public or private. I am a big fan of Juno iris--and Gothenburg has one of the best collections along with Kew. We grow these outdoors, however: Gothenburg is generous and has shared many bulbs with us over the years. It is possible that some plants in your garden trace indirectly to them as well! Iris graeberiana x magnifica, at height of bloom in the public bulb display I was charmed by this hybrid juno--which I suspect would grow gangbusters in our xeriscapes. Anemone biflora in its dazxzling scarlet phase--in the public alpine house display I have admired this bulb in books for decades: what a treat to see it in "the chlorophyll" (plant equivalent of "in the flesh") Androsace (Douglasia) idahoensis--a very rare native American alpine grown to perfection in the backup alpine collections. Don't look for this anywhere in American public gardens--you will not find it. There are literally hundreds of American wildflowers growing throughout Gothenburg, a distressing number of which are NOT being grown by American botanic gardens. Sometimes we forget that botanic gardens should be about plants (ahem!) instead of distractions...but I am getting on my soap box. Sorry! Primula renifolia, the rarest primrose in the Vernales section, recently introduced from Caucasian cliffs by Gothenburg staff. They would not be thrilled that I'm showing this a big past peak of bloom--but this is a plant of great pride: the most unusual of its section and a spectacular new garden plant. They should be proud. The public is flocking to visit the bulb collections, although the day was blustery... Their garden is loved by the citizenry. And botanic garden afficianodos around the world make pilgrimage to Gothenburg: our Mecca! One of many dozens of species of Fritillary blooming now--all meticulously labeled. Some of us are proud to be Frit Freaks--although many in the genus are chequered brown and green and invisible to ordinary folk. Too bad for them! Rare Asiatic saxifrages in the porophyllum section, some still unnamed after decades in cultivation. You will not find these at your local Wallmart, incidentally... More treasures...ho hum..... Most of the dionysias were finished blooming (their flowers trimmed off to prevent rot)--but Dionysia khuzistanica still glowed in the Dionysia house. Just a tiny fraction of the treasures in a few of the many glass houses--and there are acres of rhododendrons, trees, perennial borders, and a rock garden with hundreds of vertical feet of relief--it would take an encyclopaedia to show it all: you must simply make Gothenburg a destination...but don't expect to see it all--especially not in just a single day!</p> "...And haply then That future country lost its gloom; More lovely in that world than this, Immaculate the white lily grows, And perfected we walk in bliss."</p> Hortus Paradisi</em>, William Bell Scott</p> More pictures from Gothenburg this week on this blog....</p>
Opuntia cycloides at my house last fall Since there will be no lilacs breeding out of this year's dead land (check the last paragraph of this Blog if you don't recognize the reference!) we must make lemonade out of our lemons! And succulents RULE! Several groups of plants are coming through this rather horrific winter in great form: almost all native plants, alpines and succulents--especially cacti, agaves and yuccas seem not to have been fazed at all by the catastrophic late spring frosts that have laid so many flowering trees, shrubs and bulbs low. Yuccarama (Yucca faxoniana and Y. thompsoniana) I doubt there are many visitors to Denver Botanic Gardens (and literally millions of people have walked by these) who haven't noticed the sculptural forms of Yuccas outside our maine Education building. When Dan Johnson first had these delivered over a decade ago from Mountain States Nursery--I was sure they would be the most expensive annuals we had every planted: I was wrong on both counts--they were a gift so they cost nothing. And they have been resoundingly, gloriously perennial! And this year is no exception. They are our permanent sculptural exhibit! And they laughted at this spring's shenanigans... Opuntia engelmannii in the Rock Alpine Garden The "average person" is probably oblivious to the enormity of the damage inflicted last week by the 7F low with little snow: I think this is the greatest spring damage I have seen inflicted in my 34 springs at Denver Botanic Gardens. So I am focusing more than ever on that graceful ballet--as the opuntias all over the gardens gain color and turgidity over the next month or two and build to their spectacular bloom season: Looking at these and our rock garden and native gardens, I think...you know: they look good as ever! P.S. Afterthought: Several friends of mine have been quoting T.S. Eliot's Wasteland, which I have hyperlinked for your convenience...which many of us philologists puzzled over as youngsters in school: this long poem opened the floodgates to gnomic, mostly incomprehensible modernist "poetry" that (like Marianne Moore) I too dislike...the first sentence of which I have filched for my starter. I sort of like Eliot's most famous poem--although I hate what it has inspired subsequently. Give me Keats or Auden or Browning any day! </p>
Winter is almost over, however there are still lots of options for enjoying the Gardens. Be sure to see some of the thousands of spring bulbs that are starting to bloom throughout the Gardens! The Mordecai Children’s Garden just opened for the season. If you have kids, the Children’s Garden is an obvious choice to visit because of the swaying bridge, the mini-theater, and the view of the Gardens and the Rocky Mountains from the Lookout. Even if you don’t have children, the Children’s Garden is a really great example of a large scale, green roof alpine garden. The Mordecai Children’s Garden is conveniently located across the street from our York Street location and is open March through November. If you live further south, Denver Botanic Gardens at Chatfield is another good choice. I also recommend Chatfield if you want to escape from the city for a while. Denver Botanic Gardens at Chatfield is a working farm, with over five acres dedicated to growing produce for our Community Supported Agriculture (CSA) program. The area also has significant historical interest, including the Hildebrand Ranch, the restored dairy barn and silo, and a one-room 1874 Deer Creek Schoolhouse. Our Chatfield location is at C-470 and Wadsworth. My favorite time to visit Denver Botanic Gardens is right after it snows. Everything is white and sparkly. There’s less foot traffic through the Gardens. Everything looks different under a coating of snow. Lots of shapes and textures in the Gardens keep things visually interesting. The Japanese Garden in particular is stunning in the snow. This time of year, you can even sometimes see flowers poking out from underneath the snow. Membership to Denver Botanic Gardens has great value. In addition to helping make Denver a better community, supporting children and adult education programs, supporting our research on Colorado plants, and generally helping us achieve our mission of connecting people to plants, membership gives you free access to all of these locations: York Street, Mordecai Children’s Garden and Denver Botanic Gardens at Chatfield. Kim Brokling, Membership Coordinator</em></p>
</p> </p> It's snowdrop time again! Surely, no plant is more intimately associated with winter flowering (okay, okay--Christmas roses may be!), and none have developed such an enthusiastic folowing: there are many specialty nurseries that sell dozens, even hundreds of kinds of snowdrops. Almost exactly a year ago I told the story of a snowdrop that fetched hundreds of dollars at Ebay auction. But truth be said, all snowdrops are precious this time of winter!</p> </p> Galanthus elwesii at Denver Botanic Gardens</p> The plant that now constitute our most robust colony behind the Succulent House along the Cheesman gate were originally used as "fillers" in a lobby court display: I rescued them and planted a couple dozen bulbs some twenty years ago. Each bulb has proliferated and this is now beginning to make quite a spectacle. Starting up just now (go check it out!). Here is a closeup of the commoner species that is abundant in the wild across much of Europe. I have grown this for over a half century at various homes--it spreads abundantly in Colorado as well--but believe me, this isn't a weed. You can always find homes for this plant. I remember this as a child in my parents home--just a few clumps here and there that spread to cover square yards by the time I was in college... Here you can see now Sandy Snyder (who worked at Denver Botanic Gardens for 17 years in the 1980's and 1990's) has managed to naturalize one of the tougher sorts in her sparsely watered buffalo grass in sun! Generally, they are recommended for shady spots where they get periodic irrigation, but many species are Mediterranean littoral plants that grow in areas that have no water from April to November. I suspect we could find sorts that would thrive with no supplemental irrigation. Three of many books recently published about Snowdrops: </p> </p> </p> By the way, if you Google "snowdrop" you will find a host of novels, mysteries and other books named for these winter beauties--they are obviously popular--especially in Europe. By the way, all the snowdrop monographs have glowing reviews--and the prices are beginning to get astronomical--obviously the time to invest in snowdrop futures! Remember to order some for planting next fall (the plants of course--not the books).</p>
Yes, Virginia...pampas grass (Cortaderia selloana</em>) does indeed grow in Denver...although not in great numbers. Observant visitors will have noticed them dotted here and there at the York Street gardens, and I have seen another half dozen driving around Denver. The one above is right next to University Avenue, and constitutes a minor traffic hazard as grass-afficionados notice it and swerve! I suspect the owners purchased it via mail order, since these are rarely sold locally ("pampas grass is not hardy" according to most pretty well-informed nursery folk. And I agree, most are not. Only the dwarf, high elevation forms are apt to be hardy here, and these are hard to find). Most Coloradoans probably don't know that pampas grass is a pestiferous weed in California--but then one man's weed is another man's treasure. I doubt that this will ever pose much of a threat in our climate. I share this picture to show that much of the creative work of plant experimentation is undertaken by home gardeners. We at the Gardens sometimes have to run to keep up! Here you can see from closer up the silky, silvery color that true pampas grass has seemed to perfect. If you have driven parts of Texas you are sure to have admired pampas grass--a popular landscape plant in that state. I used to drive down at Thanksgiving each year, and the clumps of pampas here and there along the way were like mile posts, or sentinels that cheered the trip. Their fluffy seedheads are amazing when they puff up. Alas! A well established clump is so massive that cutting it back each year is a chore. This is one of the hazards of growing large grasses anywhere. Confusingly called "hardy pampas grass" (a paradox if you think about it...), this is the most commonly planted giant grass around Denver. I am sure half the people who grow it think it is pampas grass, and if you look up and compare, you will see there is a family resemblance. But while the TRUE pampas grass comes from South America as the name suggests, Ravenna Grass is from the Mediterranean. This still grows abundantly in the coastal marshes near Ravenna I've been told. This is by far the most vigorous and giant of commonly grown grasses, and a large clump will often produce vigorous seedlings nearby that should be dug while young. A large clump needs a front end loader to move or remove...be warned! Until recently it was classed as an Erianthus</em>, but has been put in the same genus as sugar cane in the last decade or so (Saccharum</em>). Sugar cane has helped make Brazil energy self reliant. Maybe this vigorous grass has biomass potential? The group that has been exploited most for that in America is another genus altogether, however... There are hundreds of cultivars selected from the various species of Miscanthus</em>--which is also often sold as hardy pampas grass. They are hardy enough but the name is taken, I'm sorry. A great deal of research is being done on these because of their famous C4 metabolism which allows them to accrue enormous biomass in short periods of time. Miscanthus have nevertheless been practically banned in much of the eastern U.S. due to their propensity to produce colossal seed crops. I have yet to see a seedling appear in Denver outside, so I think we can grow these without guilt--except that these are the most water demanding of these larger grasses. Don't try them in your Xeriscape! My current favorite giant grass is native not far from us here in the Rio Grande Valley. Plant Select has chosen to feature this plant in 2006 and I can vouch for its toughness. The plant you see in the picture is in my garden, on very sandy soil where it bakes for months on end and gets precious little water. Even so, it makes a fabulous fountain of golden seedheads that persist through the winter months. Indeed, all of these pictures were taken this morning, January 24. The greatest reason to grow these pampas grasses (and their pretenders too!) is that they provide drama, beauty, movement and interest in the depths of winter for months on end. If you grow them, please resist cutting them back until February so we can enjoy their splendid display! But do cut them back hard so that the new growth will be fresh and green for the coming year!</p>
