Monday, November 15, 2021

Stranger in paradise

Bursera simaruba

 Most horticulturists I know have a "thing" about paperbark maples and madrones--admiring their wonderfully peely, red bark. I was delighted to find a tree that possibly even out papers and out-colors even these: Bursera simaruba is widespread and common in the dry tropical forests of Jalisco. This is only one of dozens (possibly even 80) species in the genus that's concentrated in Mexico, although I did once see a gnarly, rather dwarf Bursera in the Anzo Borrego desert of southern California.

One of many enchanted Mexican sunsets on our trip...

That was a sneak preview of a blog I intend to do about the remarkable Puerto Vallarta botanic garden: the real purpose of this trip was basically to finally get outta Dodge (or Denver in my case) where I've been holed up over two COVID-cursed years: OK, OK, I did drive out to Portland last summer, and we did get to Tucson earlier this year, and Santa Fe several times earlier--but this was the first real PLANE trip since COVID settled in its dreary pattern.

Two dear friends (Steve and Kathy Aegerter) persuaded us to join them on our first "all inclusive resort" experience (it's practically a second home for them--they've come to know many of the staff as friends--which made the whole thing a lot more meaningful to us)...

I'm relatively resistant to the tropics: the flora is so vast, the climate so warm, the impact of humanity is so intense...but sometimes you have to relax and admire the tiny full moon tangled in the coconut palm fronds perhaps--from our little patio at the hotel...

We only took a few dips--but walking the strand and watching egrets fish for tiny fish was a delight.

Food (which I like a tad too much) became a bit of a too muchness. I am not sure the endless free food and drink of cruises or resorts is a good idea for certain kinds of gourmands...although this seafood platter was at a restaurant in the hills...

And the tropical dry forest and its understory of Muhlenbergia really made the trip for me: this was taken at a Macaw Sanctuary that was incredibly inspiring which I intend to blog about more extensively soon...

Dioon tomasellii 

I featured this on my Facebook cover, and got a lot of ribbing (for showing a plant at a bird sanctuary, for calling the fruiting body by the wrong name, for you name it!)...but finding a cycad in ripe seed in nature is a gratifying thing! This was my first wild cycad I'd seen outside of Africa, so it was a pretty special day--and a gratifying 10 day escape from routine! And now two weeks in Argentina!

Friday, November 12, 2021

In praise of Bradford and Chanticleer pears!

I suppose I just lost any shred of credibility I may have earned among tree lovers by my declaration: hold your dang horses, kiddos, and read through my commentary and If I don't persuade you, well...then YOU are the hopeless one!

These pictures of various Pyrus x callereyana and P. x ussurensis pears (quite a welter of them are grown and sold in Denver) were all taken on a few mile drive through our fair city on November 11. 

You should notice from the backgrounds that most of the cottonwoods, ashes, maples, elms and other prevalent street trees are naked. Okay, the oaks are glorious--but horribly underplanted.

I suspect the Asian pears probably consitute only a fraction of our urban canopy: 2%? Surely not much more: but right now you will find one or two on almost any block glowing far more than my poor pictures reveal (snapped often from a moving car) on a typically glaring clear Denver day.

Increasingly over the decades I have come to think of November as "Asian pear month"--they have a burnished, glorious transformation of colors: some have lots of orange and even yellow, and some are nearly crimson. But all are emphatically colorful when the rest of our deciduous trees (except for the blessed oaks) are increasingly naked.

 Arborists and sophisticated tree types (not to mention people from maritime climates where these pears are undeniably a pestilence) love to deride the ornamental Asian pears: "They split in snows", "Their flowers stink", "they are unreliable", "They bloom too early" (I admit that many years when their white flowers are frosted and turn mushy brown they're pretty ugly for a few weeks--but the same could be said for magnolias).

Like aspen, birch, Freeman maples and fruit trees generally (their falling fruit makes such a mess!), designers, arborists and knowledgeable plant experts do everything in their power to dissuade homeowners from planting the ornamental Asian pears. Try as they may, I see more and more aspen around town--and Freeman maples have been astounding in their color this year: both seem to do well in many of the sites they're put. I don't see as many birches as I used to (which I regret: I like them and they can often do very well and some species resist borers pretty well). And fortunately, people keep planting pears. Go for it! 

*P.S. some time in the early to mid-1980's John Creech (legendary U.S.D.A. researcher and director of the U.S. Arboretum) spoke at the now defunct Bonfils-Stanton lecture series that once brought America's greatest gardeners to Denver. Our staff was a fraction of what we are now, and I often was the only one who could introduce people (i.e. who had a clue who they were!) and I introduced John as "the man who is responsible for 'the Bradford Pear'", At lunch he gently informed me that he was no longer proud of that achievement (and would I not broadcast it further!)...he already had an inkling perhaps of its frightening potential for invasiveness in his area. I have never seen a seedling Bradford or Chanticleer pear in Denver--and doubt I ever will, however. John forgave me my gaffe and was impressed enough with me he recommended me to serve on A.H.S. Editorial Board, where I still serve almost 40 years later: if you do not subscribe to American Gardener (the finest horticultural magazine in North America (along with the Rock Garden Quarterly I hasten to add) do remedy that: sign up here: to get American Gardener by joining the American Horticultural Society!


Wednesday, October 27, 2021

Aspiring veronicas just get no respect!

Veronica gentianoides 'Little Blues'

Why "aspiring"? The adjective is cognate with "spire" and likely "spike": these are the taller veronicas I'm addressing--not the gorgeous dwarf blues. One of the reasons we garden (especially ROCK garden) is that every year brings new surprises--often in spades (so to speak).  You form an opinion (such as "Veronica gentianoides is a bit of a bore"--great for large perennial plantings perhaps, but out of scale for rock gardens...I suppose it was the name that made me pause and buy this plant (a Jelitto introduction by the way, grown by my colleagues for Denver Botanic Gardens plant sale). When it bloomed the first time I was charmed--and it's come back several years a tad more strongly: I've been won over...but then I'm a veronicophile to coin a word.

Even "plain old" V. gentianoides can be fetching grown well, as it was in the garden depicted above--in England I reckon. In the common, pale cultivar often encountered.

This picture was taken of V. gentianoides along the pathway of the "old" perennial border at Denver Botanic Gardens (which has been removed a few weeks ago: I wonder if the accession was preserved elsewhere at the Gardens? asks the Senior Curator)...I am one of those old fashioned folk who don't think Libraries should dump books if they haven't been checked out recently, nor should accessions at public gardens be lost without a damn good reason

Veronica spicata 'Icicle'

Much commoner in cultivation one finds the endless permutations of V. spicata--more often in pink and bluish lavender. I'm sure I have a dozen pictures of these I took back in the dark ages on transparencies--you'll have to settle for this one shot. Neither do I find V. incana, which has been lumped with spicata (harrump!) and is growing lustily in a hot spot on the south side of my house--a great plant which somehow I don't seem to have photographed. I'll certainly do so next May!

One of quite a few strange and wonderful veronicas I've grown from seed collected in western Asia by the Czechs over the years. Allied to V. teucrium (a.k.a. V. latfolia) some have persisted: Flora of Turkey, Flora Iranica and my Caucasian wildflower books disgorge such a welter of veronicas I have yet to determine which one it is. I'll spare you pictures of 'Crater Lake'--though I have a killer story about it I may share one day.

Possibly my favorite of the "aspiring" veronicas is this one: V. porphyrantha, photographed here in my garden.

Veronica porphyrantha

And here it is in far Western Mongolia: a striking plant which hasn't entirely settled down in cultivation yet, alas! Although I believe Jelitto has sold seed, so there's no excuse!

Veronica wormskjoldii

I end on Colorado's showiest (alas) veronica--not quite up to Asian standards I fear...and burdened with a name stranger than my own! Now that I look at it, there is a bit of a resemblance to 'Little Blues' that kicked this piece off. Properly photographed it can appear fetching as in Southwest Colorado Wildflowers...well, at least it's ours. As much as I love our native flora, when it comes to Veronica, I'll grow the Eurasian species instead, thank you!




Sunday, October 24, 2021

Autumnus miraculosus: let us now praise maple trees!

Acer circinatum this week in Colorado Springs

Colorado does nothing according to plan: some years we have 2' of snow in late May, or early September. I recall a series of miraculous springs (gradually warming, no late frosts) 2006-2010 that convinced me we'd achieved the ideal climate. Then a polar vortex in April even killed daffodils and crocuses! This year we've dodged the frost bullet for many nights: Impatiens, Castor beans and Begonia are all still looking good. And the fall color is rapidly approaching its zenith.

I got the above picture of the above in my email today from Judith Sellers (a friend of a sufficient number of years neither of us will confess how many). Judy bought a 5 gallon vine maple (Acer circinatum) at a Denver Botanic Gardens' plant sale in 1983: today it rivals many that grow in the wild in size: Colorado Springs is over 6000' elevation, in a solid Zone 5--where vine maples aren't suppose to grow. Obviously it does! There is still so much to be learned about winter hardiness! I've included a note* Judy sent me about the tree at the end of this blog.

Acer amurensis

 Of course, Ginnala maples are the commonest small maple in our area for good reason. I admire this one every day this time of year (it's blocks from my house where I go to turn for work). They are reputed to spread viciously from seed in the Upper Midwest, where many states now ban their sale. I have not observed this in Colorado. But then I've never seen a Miscanthus seedling hereabouts, and it's become an "invasive"' in wetter climates. Which is a pretty good indication that invasiveness is a relative term that is largely contextual.

I took this picture last year--but it was every bit as showy this year--only bigger! In my home garden (a gift of my brother-in-law Allan Taylor who is in an advanced stage of arboritis.

Most tree nerds would agree that the most underplanted maple in our region is the bigtooth maple (Acer grandidentatum), which goes by many other common names as well (Utah maple, Wasatch maple--both of which are perhaps a tad limited since it grows from Texas to British Columbia!). I have several in my garden that are thriving in a border than never gets water: they're very drought tolerant!

Here's a fine specimen at Regius University.

A closeup of a typical specimen: the color is usually similar to Sugar Maples, to which it is closely related (and with which it has been lumped by a few botanists). 

Seedpods on Acer semenovii, which has yet to turn color for me...nothing wrong with those samaras though!

Acer nigrum

The champion maple in Denver is near the Museum of Nature and Science: I make a point of driving by this time of year whenever I can. This was taken several years ago--it's just starting to turn this year. Most "sugar maples" in Denver turn out to be Acer nigrum--which is morphologically similar, but tolerates alkaline soil and our extremes of heat and drought better.

I've skipped back to Acer grandidentatum: Oh well--this shows dwarf clones growing by the waterfall at Betty Ford Garden in Vail. I missed seeing these in color this fall--my bad! Worth the 100 mile drive.

And here's a single specimen: I actually have two dwarf bigtooth maples in my garden--and one is coloring up beautifully: nowhere nearly this size. I wonder if these two come from the days my brother-in-law Allan would cull the seedling fields at Fort Collins Nursery wholesale looking for genetic dwarfs he'd pot up and share.
Acer triflorum

While every plant sophisticate in Colorado struggles to grow Japanese and paperbark maples, it seems that this tree from northeast China and Korea will prove much easier and more accommodating. This specimen has grown for years on the north side of DBG's education building.

Acer triflorum a bit closer up

The fall color is quite stunning

Acer griseum

And there are those who insist on the true paperbark maple--here's one about twenty years old in Boulder.

Acer griseum

 The fall color can be spectacular on this as well...

Acer palmatum at Denver Botanic Gardens

Of course "THE maple" everyone yearns to grow in Colorado is the classic Japanese maple. We had a grove of then for years at DBG that was grown from wild seed collected in northern Japan. These (like 90% at least of all Japanese maples and Japanese cherries) perished in our area during one of the last "polar vortices". 'Bloodgood' is the one cultivar that fared better than most--but this blog is an attempt to remind us that there are a wealth of maples out there--not just the Japanese!

Acer palmatum
It is a fetching plant I know...but after you've seen the spectacular specimens growing on either coast--with enormous trunks and vast crowns that are not filled with dead branches, you'd be a fool to try to grow this in our harsh steppe climate...
Acer saccharum 'Green Mountain'

I advise people in our area to avoid planting sugar maples (unless you live very near the foothills in the Black Forest, Colorado Springs or west of 28th street in Boulder where soils are naturally deep and acid). That said, this cultivar has performed spectacularly along the street in front of DBG (makes me wonder if it isn't actually Acer nigrum?) There's so much yet to be learned about adaptability of plants to our area.

Acer granatense

I have posted this picture before I took in Anadalucia exactly 20 years ago this month. It had not yet developed its full fall color. I have a hunch it would prove as adaptable as Acer monspessulanus, which I have featured too many times already in this blog...but has anyone introduced this yet? No they're too busy killing Acer palmatum! Honestly, I think the intelligence of Homo sapiens is overrated!

Dan Johnson and Acer granatense

 Since there are around 160 species of maples in the world, this blog could conceivably go on for much longer....but it's the peak of autumn color here in Colorado (and elsewhere too I imagine): better to go out and enjoy them in the rapidly transforming chlorophyll....or should I discuss the hundreds of cultivars of Acer palmatum we shouldn't be growing here on our windy and sunny Plains? Particularly since we CAN grow so many of the above well!


*Judy's note about Vine Maple: "One more thing on the vine maple:  As you know the last two falls have been very hard on woody plants with overly warm temps only to see a winter storm come in suddenly, dropping temps dramatically and catching many that had not gone dormant.  I lost several prizes including my 20-year-old dwarf Japanese maple.  That hurt.  Also a Pink Dawn viburnum,  My Northern Lights azalea was severely damaged as was a cotoneater and a Canadian lilac.  Looks like I will also lose a prized, north-facing white fir that's probably 60 ' tall.  Remarkably, the vine maple was unfazed which surprised me in its hardiness.  I don't know if that was the reason or maybe just because it is planted so close to the house.  In any event, losing it would be a terrible loss.  Fingers crossed,'s supposed to be 75 here today (October 24).  

Thursday, October 21, 2021

A-listers! A fond look back at a floriferous year...


Aquilegia flabellata 'Nana'

What a strange year, as COVID-19 continues to rage, our gardens quietly perform their floral ballet: this year better than ever really. We had an extraordinarily prolonged, wet and wonderful spring (wettest in Denver history apparently) so plants grew luxuriantly! I had planted so many new things last year, and had so many more in the pipeline to plant this year that the garden has been a constant source of surprises. Of course, some like this miniature columbine are perennial classics I'd never want to be without (here growing in a trough).

Aster sedifolius

Not as spectacular as it is at Kendrick Lake, where it makes a perfect sphere of blooms, Aster sedifolius did produce a smattering of flowers--the best yet. I can hope we'll end up with something like their cousins in Lakewood!

Aruncus x 'Zweiweltenkind'

It is reputed to be a hybrid between A. dioicus and A. sinensis produced by Karl Foerster--it is much more compact than typical A. dioicus, and very tough in my experience. Siting typical goats beard is a little like parking a Humvee in a busy neighborhood (I've done neither yet).

Arenaria attica

Not sure when I got this--but it's taken off and promises to be a fine small scale groundcover.

Arabis carduchorum

I remember seeing this at Kew in 1981: I've grown it since then here and there--one of the toughest, most gratifying of rock garden mat formers. I've never seen it sold at a nursery.

Aquilegia grahamii

 Alas, this may have perished after blooming: a narrow endemic of the Uinta Basin--it's one of the most delightful dwarf columbines. Fortunately, it set lots of seed (some going to NARGS of course!)

Aquilegia coerulea

Since this was named exactly 200 years ago by Edwin James, I had to include a picture of our famous state flower. That's Paeonia peregrina behind, completing the patriotic color theme!

Aquilegia chrysantha

I'm quite sure I didn't plant this in the container--but I'll take credit for it anyway! What passes for chrysantha is surely a complex hybrid of several Southwestern columbines. The Denver Gold strain is incredibly vigorous and long blooming.

Aquilegia canadensis (dwf. form)

Can you tell I like columbines? But then it's Colorado: you're required to by law.=

Anthyllis coccinea

The one indispensible Anthyllis: every other one I've grown's been weedy. This one is compact and the flower is electric.

Anthemis biebersteiniana

Or is it A. marshalliana? You tell me. Under either name one of the best of its tribe.

Anemone x seemanii

I have several clones of the hybrid between A. nemorosa and A. ranunculoides....hope it spreads as its parents do!

Androsace taurica

Presumably from West Asia, this is by far the toughest of the villosa complex for me--in the ground or in troughs.

Androsace sarmentosa

Or is it A. primuloides? Or chumbyi....or perhaps A. studiosorum? Whatever the name, can't live without it!

Ancistrocactus tobuschii

A wonderful gift from Pat and Joel Hayward who collected one (perhaps it had been dislodged) on their property where hundreds grew. The books say there are only fifty or a hundred left in nature. WRONG!

Amsonia illustris

My signature bluestar: this is a self-sown seedling. Fortunately, there are not too many of these. Or maybe not so fortunately?

Alyssum oxycarpum

For years Mikl Brawner and Eve Reshetnik have sung the praises of this (I got it from Harlequin's). I think I'm getting sold on it...

Alopecurus lanatus

My favorite grass. The rabbit-ear flower/seedpods are cute--but with foliage like this who needs flowers! Finding this on Ulu Dag above treeline was something I shall not soon forget!

Alopecurus lanatus on Ulu Dag

In case you didn't believe me, here's the picture taken on Bithynian Olympus on July 8, 2015. By the way, note that once a plant is securely in cultivation where seed can be produced in abundance, adapted to garden conditions there's no need to re-collect in the wild unless there's a specific reason. Propagation prevents depredation.

Allium zebdanense

One of my fifty favorite alliums! A gift of Gary and Tom Whittenbaugh, in Oelwein, Iowa--who have one of the finest rock gardens in America.

Allium senescenns 'Glaucum’

Mark McDonough--who knows a thing or two about onions--tells me this name is wrong. But he hasn't told me a better one--so I'm sticking with the name everyone uses--a classic plant.

Agave toumeyana v. bella

Alas, my toumeyana v. bella doesn't look so good: I wouldn't be surprised if some of these bloomed soon at Denver Botanic Gardens where I photographed this--one of the choicest hardy plants.

Agave neomexicana 'Skullhead'

If Dan Johnson could clone this agave, he'd be rich (considering the proliferation of Halloween tchotchkies!). Alas, it's not genetically stable. Tissue culture fails every time.

Adonis amurensis

The first floral spectacle in my garden, starting in January some years. I wish I grew every Adonis.

Acer buegerianum

Alas, not in my garden (all the others have been but the Agave): one of the surprises of this summer was being shown this on Fort Lewis College by Jeff Wagner. Never expected to see THAT in lofty Durango!

Acantholimon cf. ulicinum

One of the few spikethrifts that has deigned to grow for me: the monsters I grew on my Eudora garden as even bigger a quarter century after we moved. They hate my sand. But a few have condescended thus far.

Abies koreana 'Kohout’s Ice Breaker’
After Verbascum bombyiciferum and the plethora of Glaucium, this is the most frequently asked about plant in my garden.  I have to admit I pause a split second each time I pass to admire it myself! So ends the list of "A's" I photographed this year in my garden. I missed quite a few--you'll be glad to know! and if I have some more "slow news" cycles I may plow through the rest of the alphabet! Watch out!

Colchicum 'Giant' photographed by Kathy Purdy

I hope Ms Purdy doesn't object to my using her wonderful picture featured on the last issue of the Rock Garden Quarterly. I show it, hoping to inspire you to join the North American Rock Garden Society. I was elected president in July: if you like my blog, you belong in NARGS!

The North American Rock Garden Society (and her sister Societies in Canada, Europe and beyond) have become my most cherished community (after my family of course, and fellow Greeks who I'd better include quickly if I intend to live long).

The Society seed exchanges (coming up quickly) have given me some of my greatest plant treasures. By the gardens who've hosted me across New Zealand, the United Kingdom, Europe and of course North America are the most knowledgeable, modest, amazing brothers and sisters of the trowel! I a salute them, and suggest you click here and join us pronto! Once you do you can visit the website any time and read the recent bulletins. NARGS has been my University where I have learned much of what I know. It is the magic circle where I've met the finest gardeners in the world. You may well be or become one too!

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