The Warm-blooded Touchy Carrot Clan

Ipomoea leptophylla, five years without water.

In context of establishing great plants into gardens, I have come to know a certain motley crew of remarkably unrelated and excellent plants that all seem to have the same problems- problems which may explain some of them being so absent in gardens. Lassoing them into a group in my mind has made it easier to deal with their funky personalities, and so I want to tell you who they are, and my trick to skipping the bull and enjoying them at their best.

-Most hate transplanting- some usually die from it.

-They have significant taproots, often hate being in pots, and hate overwintering in a pot even more.

-They don't emerge until it's freaking hot outside: no-shows of spring but kickass bloomers in summer. 

-They are usually big and herbaceous, leaving big old holes when you clean up their great freaking skeletons. A challenge to design with...

-They are too awesome, once in the garden, to give up: They tend to bloom in the worst of summer heat and all will grow without water for me in Western Colorado.

They all look so very different, but if you close your eyes and consider how they behave, I swear they are all the same damn plant.  So who are these rascals?

-Coyote Gourd, Cucurbita foetidissima. This one REALLY hates transplanting.

-Desert Four-o-clock, Mirabilis multiflora.  Many gardeners have noticed that volunteer plants are always tougher than their mom. Probably the least fussy of the lot and comes up a bit earlier.

-Jimsonweed/Moonflower, Datura wrightii, Hardy to say zone 6, it's a classic alley plant in Grand Junction and hardy in hot spots in Denver. 

-Bush Morning Glory, Ipomoea leptophylla. This one is rarely in commerce but lives foreverrrrr when it does get a big ol' root down. With flowers like that you know that it's looks are not the reason it's not popular.  

Cucurbita foetidissima is a giant octopus with shark fin leaves - it needs room!

Now, many of us have tamed them into air-pruning pots, bands, whatever, to grow them in the nursery. Some folks are very careful with the fussy roots. I have had good luck taking half or most of the leaves off of newly planted plants to reduce the root stress- it works really well. But there is an even better way. 

1. Sow them directly in their spot as seed. (no compost or amendments!)

2. In summer (like June/July).  

3. Defend the seedlings from crawling chewing bugs (like with a metal collar made from a beer can) and 

4. Water the living crap out of them when it's hot so they grow big and fat and fast to be a nice size by fall to overwinter with big legs and a full belly. (This means a good soak 1-2x a week when it's above 70F, and stop in fall.)

They will come up strong the following season and be a mature blooming plant without supplemental water or bug defense, far outpacing a plant that was planted and may not have overwintered anyway. The other great advantage is that the taproot is allowed to shoot down uninterrupted like a drill and yield a perfect root system with no traumatic history- no need to re-grow the taproot a year after planting. 

The challenge designing with them? I'm not sure I have a perfect answer- but simply having room to be placed behind other small shrubs or herbs will hide their spring-empty seats from view. It helps if those plants in front can tolerate shade when the thugs do come up and cast a broad summer umbrella over their neighbors. As for their big dead skeletons, chop them up, stomp on them, or grab them like a giant dead bouquet to haul off in one massive load. If you grow the four-o-clock you know what I mean. 

I think the story behind these guys is that most come from light soils whose water drains deeply and quickly (and they chase it with their taproot) and that these plants all specialize on monsoonal summer moisture.  Where I live, summer rains don't always happen, so the native populations don't recruit newbies on those years, like Mirabilis glandulosa. This year of course we are getting hammered with lovely summer rain which has turned the river to mud and is washing away highways like it's California or something, making all the NARGS folks detour on their way to the meeting in Durango next weekend. 

The handsome late July leaves of a datura, in bud, that I sowed in early June.

I feel like there are few more of these kids I forgot to name by species- (help me out and tell me who I forgot) You know how to identify them now and what to do to tame these marvy tigers in your native dry garden. 

Sources of Expanded Shale and such

 

There has been discussion among rock gardeners, roof gardeners, bonsai growers, and the crevice people about sourcing expanded shale and other permeable aggregates. These materials are like porous gravel, holding water and nutrients without organic material- which is very useful mixed into crevice garden soil media and in containers to grow alpine or rock plants.

Here is a list I've been compiling:

Haydite (Ohio) 

Seramis (Germany/Europe/UK)

Permatill (by Stalite) North Carolina

Turface (actually calcined clay) or “Pro’sChoice” brand

Trinity Expanded Shale (Golden, Colorado)

Utelite  (Utah)

Soil Mender brand Expanded Shale (Texas)

Cat litter/“Oil-Dri”- coming in bags at the pet or automotive store, these occasionally turn out to be useful expanded shale, calcined clay, or diatomaceous earth, but most of the time are just clay clods- adding water will quickly reveal the truth. A source for desperate times. 

Broken pots- Terra-cotta, porous pots have the absorbent qualities of all the above, but this is not true for vitrified stoneware pots which are fired hotted and not porous. Broken terra-cotta may have been used for a very long time historically by rock gardeners in-the-know! Not a bad plan-B if nothing else is available or you want to dispose of old pots.

Secrets of Dogtuff, Eryngium leavenworthii, and Amber Wheels

 Ever find out something about a plant that sure as hell isn't in the books about them?

Like Gaillardia 'Amber Wheels' being rhizomatous.  Oh yeah.

Surprise #1

Hard-blooming Gaillardias are anything beyond a short-lived perennial. Usually you get seedlings off the mother plant before she dies. But last year, when I was planting bulbs in a high elevation flower bed designed by Scot Ogden, I saw shallow rhizomes everywhere. I keep an eye on that bed to keep certain nasty rhizomatous grasses out. But these white threads- I followed them back to the plants. Whaaaaaat? I emailed Scot to find out that the Gaillardia was Amber Wheels, a seed strain based on a wild collection by Larry Vickerman of Denver Botanic's Chatfield campus.

Just to make sure, I took root cuttings. They worked.

The original plants have been humming along since 2016 with no sign of getting tired. Fantastic.

Surprise #2.

Eryngium leavenworthii- a Texas version of sea-holly.  I had to try it because some of the coolest designers I know have use it. It's listed universally as an annual. So I got seed in winter, like you do, sowed it in the greenhouse, and planted it out in spring. And it slooooooowly established. I watched those tiny puddles of plants do nearly nothing all year. As the season wore on I grew more sure they sucked for my garden, or sucked in my climate, or I sucked at growing them, and then winter came. And they lingered.

Because they are biennial for me- and a friend in Iowa told me he has the same experience. What the heck? I'm grateful. Just to write it down somewhere: Eryngium leavenworthii is biennial if it isn't annual. 

Surprise #3.

I'm usually pretty careful about adopting new plants too fast because I hate to discover some plant's weakness or worse- its dark secret on a client's dime and in their garden. My friends and Chelsea (native) Nursery are even better about that. The reality of the cutting edge is that it's R&D- it's messy and unknown until tested well.

So I was slow to fully embrace dogtuff, the amazing bermudagrass that is all the rage in cutting-edge gardens in the cold dry American west. (Cynodon transvaalensis) It is native to Africa, was mysteriously found on a ranch in CO, passed between many plantsman's hands until Kelly Grummons found the ideal use for it as a super xeric, no-mow, dog-proof turf. 

I was mostly leery because I was raised in a valley where bermudagrass is a horrible bane to gardens and landscapes. The typical mongrel bermudagrass has ridiculously deep rhizomes, going an average of 18" (45cm) deep invading beds and swallowing your groundcovers with its coarse leaves and dagger-sharp stolon tips and rhizomes that jamb into your feet and easily punctures sweed-cloth. Why would I risk planting a short greener version of that crap?

So I have tested it and been on a mission to find out how badly it spreads underground. I have awkwardly asked to dig post-holes in friend's gardens. Well, whaddya know. It doesn't. Not that I have found. Before I was comfortable with that, I installed a patch for a client who wanted it, but not without containing it with a deeply buried bamboo barrier. In the end that was totally unnecessary. 

Trench and bamboo-proof vest.

Just a month after planting plugs.

What is more- I planted it in our back garden to give us a whopping 6' (2m) wide "lawn" where several paths intersect, and that doesn't require we own a lawnmower at all. We don't. And so on principal, I've never mowed it. In fact, I didn't cut back the dead material last spring to see what would happen and.... nothing. It greened up as per usual.  Lastly- here's the biggest surprise. For fun, I watered it once in 2020. May. One good soak. And I decided to not water it until it looked stressed out, so I could test just how dry it can grow. 

I waited. And waited. In August, at noon, one part looked almost imperceptibly stressed. I waited. Green again until frost.

What!? Kelly told me that during a wet summer in Denver he didn't have to water it. But in Fruita? In 2020 we got 105F (40.5C) with only 5" (125mm) out of our usual 9" (230mm) precip. Our dogtuff grass was satisfied with groundwater- which is 8' (2.3m) down and only in the summer. Wow. It doesn't have rhizomes but somehow the roots can get to water that far down?

I estimate it would be perfectly beautiful with a consistent 2 week watering schedule on any sunny soil. Now, if only I could find a basic irrigation control box that could be programmed to water that little.

Dogtuff is good. It doesn't run.

A Flame in the Tinderbox: Crevice Gardens in California (and Earth, Generally)

Photo: Michael Uhler

Forced by writing a book on crevice gardens, I started to think about crevice gardens in all climates, which highlighted where they are (or would be-) most useful. The things that make them powerful- biodiversity, recycling, and microclimate creation- have different weights in different places.

Most of this thinking was informed by watching them take off here in Colorado. So, to myself, I predicted the next hot spots: California, because of its longer history of water-use awareness, native gardening, and a big population of gardeners and plant collectors. Then Arizona- one of the recent fastest growing suburban places in the west, but very limited in water. They have an established “desert” aesthetic that liberally embraces new hardscape styles. I think aesthetics may be a big driver there. Then perhaps Texas, with its amazing natural biodiversity and its own gardening identity. 

What I am more blind to, like a typical american, is the rest of the world. The Japanese have a perfect score of adopting something and elevating it into and art and science, while putting their own stamp on it: Aquariums, cars, whatever. A genus of plants is a genus of plants- like Morning glories or Chrystanthemum, until it goes to Japan. It comes back an entirely different thing. They just have a culture of honing, dedicating, and perfecting skill. Can you imagine what they will do with crevice gardens? They’ll leave us looking like cavemen. Get ready to be an old hat.

I think that crevice gardens (can I just call them CGs now?) will continue to fill in within the intermountain West, Midwest and eastern US, where they are already scattered. Same for the UK, Canada, Ireland, Scotland and New Zealand, places all within the well-connected english-speaking rock garden world. I don’t know much about CGs in Australia yet. CGs have been around western places a while and will steadily grow. Same for Europe. But South America, Africa, middle Eurasia, and all the islands- I have only the vaguest of guesses. I think we’ll see isolated and adapted use of CGs in tropical places, since chasmophyte plant forms can shift seamlessly into epiphytes there. The middle east could be incredible- it’s already a strong influencer connected climactically to Arizona and Mexico.

I don’t know enough about China to know when and how things will develop there. The most populous country on earth, I’m sure it will be big. The second biggest? I’m afraid to betray my own biases, but I don’t expect anything big and soon in India. I have no doubt private gardeners or isolated innovators and geniuses will create amazing things, but the country as a whole suffers from a lot of status quo and a glut of sinecures (easy prestigious jobs with high pay and little work or skill). All the public gardens I personally saw there unfortunately suffered from that weight. The hashtag #rockgarden in India is saturated with narcissistic teen selfies at Chandigarh.

I also guessed that Turkey was deeply unlikely to see crevice gardens anytime soon- and boy was I wrong. I lived one summer in Turkey, so the place is a certain home to me. The first public CG is at the Nezahat Gökyiğit Botanical Garden in İstanbul. It’s big, and they feature turkish endemics in a sophisticated way. Then, in SE Turkey: Antalya’s Mediterranean University reached out to Paul and I to build one in marble, no less, but the plan was snuffed by the pandemic. 

The Crevice Garden in İstanbul's NGBB.

Photo courtesy of Mike Smedley, future host and de-facto ringleader of June’s NARGS annual conference. 

But I’d like to swing all the way back to my first prediction: California. I was keeping my ear to the ground when Panayoti was the first to let me know it was happening. 

The Tilden Regional Park, on the foothill-ed edge of Berkley, CA, specializes on California natives, honoring the most floristically diverse state in the union. I was generously filled-in by gardener/builder Michael Uhler and director Bart O’Brien there about their project. In the last two years, they’ve set tons of a glorious rock they call “Mariposa Slate.” They have taken a slow, focused and deliberate approach to maximize and leverage the best of what a CG can do to grow specific plants. Let’s be frank- most of us build something cool and see what we can grow in it. They have taken a more thoughtful path with a focus on Sierra Nevadan alpines. Here is a link to a preliminary newsletter article on it.  

The next issue, Vol 25:1 (2021) will feature a meaty and wonderful article by Michael about the whole history of the crevice garden and a deep look at the plants it was designed to host and their origins.

Photo courtesy of Michael Uhler

Bart says that there are now at least three private crevice gardens that were influenced, spurred, or otherwise affiliated with Tilden Park project. I am reminded of the time when Denver Botanic’s Mike Kintgen put in the first two at Denver botanic. That was the spark that ignited interest in Colorado and well beyond. 

I am holding onto my seat and grabbing for the seatbelt to see what is about to happen in California. 

Is this the first? Crevice Garden conference/study day

This may be the first all-crevice rock garden event I am aware of. NARGS is hosting an all-day zoom conference: Saturday Feb 6th.  11am-5:30pm EST (you can watch it later if you are in a different time zone, luckily!

The CREVICE GARDEN VIRTUAL STUDY DAY

$25 for members, $50 for non-. My talk is mere business and pales in comparison to the diverse fun coming from the other five presenters, including the anticipated lecture debut of Susan Sims. Also, Talks will be nice and bite-sized. 

The nice thing about online events is that you can pick your own booze or snacks, and whether you wear pants or not. I enjoyed a green cocktail (gin and chartreuse) to honor a cactus club meeting last night. 

What will you bring to the event? 

(click above if you have not decided)

The Psychological War in the Garden

I feel like all of my gardens are a war. A war between two concepts: peace and excitement.

Peace is: meadows, grasses, harmony, unity, relaxation, comfort, the steppe, grain fields, being able to see far. Safety, order.

But excitement- it’s variety, color, surprise, being busy, nooks and crannies, jarring contrast, a messy plant zoo unified by nothing but lust. 

I think this battle has not always gone well: it’s worst collateral damage being the failure of the general design of a garden I’ve made, where the plant collectorship gets out of hand and the space has no spirit of its own. Or, if the other side decisively wins- something that is pretty, giving you an immediate inviting feeling, but basically boring beyond that, functioning like an agreeable background to whatever non-botanical activity you are doing like an overly quiet and polite host with no opinion of its own. 

It’s taken me years of making gardens that some folks enjoy but leave me cold to realize this. Finally knowing the exact problem has made creating solutions fairly easy. 

I don’t think that it’s about a “balance” between peace and excitement, but perhaps layering them. Or fostering their coexistence. Like oil and water- a hackneyed metaphor we take for granted: “yes, yes, oil and water don’t mix, shouldn’t be mixed” we say, but I ask- what is butter!? Glorious! Certainly you wouldn't defame butter? A natural phenomenon, a mixture of oil and water, thanks to emulsion, a brilliant mechanism that brings the two together. What is the mechanism to marry two disparate impulses?

Here’s one for gardens. Just my basic go-to at the present. Lay on the harmony/unity heavy enough (to make peace/space) that you can lace it pretty liberally with variety. In a meadow, this can mean a matrix (which doesn’t mean a network, it means a womb) of one or two types of grass, interspersed with a variety of bulbs and herbs. In a rock garden, harmony can be solidly established by a heavily used single kind of rock, and plants can basically be anything you want, but the accident that they are all smaller or cushion-shaped will, as a byproduct, create a certain unification among all the different little guys. 

For a lawn, that means a totally predictable, 100% safe monoculture of turf with no room for any variety or anything dangerous like excitement, and that is dead boring and you know it. 

Another example of meshing variety/fun and unity/order:

In pure numbers, this can mean a garden rugged-out with three dozen Mexican Feathergrasses, peppered by half a dozen accenting bunchgrasses like Muhlenbergia or something, an ephemeral underplanting of two hundred muscari, all of those creating a super solid foundation, a vibe, and then finally, start getting interesting or varied with a dozen Echinacea, ten Eryngium, twenty Kniphofia. Lastly, the variety can be represented and solidified with say fifty different species in quantities like onesies and foursies, who are embedded in the grasses like gems on a crown. If there is only one emerald among the mixed gemstones on that otherwise golden crown, will it look like it belongs. And these plants for variety get even better if they are seasonal- appearing at certain times, creating surprise, keeping you interested. The fun part here is that if you take out flowers over the years or try a new one the rest of the garden won’t notice. It won’t disrupt the vibe. The party will go on while dancers come and go.

In understory or forest-like plantings in shade, it’s too easy to make harmony, because in nature, the understory is often dominated by sheets of one shade-tolerate ground-cover for acres and acres. What is tricky is variety, which might just come down to the long game of hunting down a variety of plants that will put up with shade and provide temporal, color, or textural variety. Shade gardens are the hardest for me because I’m a plant nut, a life devotee of that botanical variety, and as a result I think over the years I’ve become careful of where and how many trees to plant. 

Back to rock gardens, because we like those. They’ve always struggled to have unity. Their potentially jarring disarray of plants lovingly kidnapped from every godforsaken rocky spot on earth have repelled the more sensitive gardeners of fragile design tastes for years. How do we deal with that? Why don’t natural rock gardens feel as jumbled? I already mentioned that an abundance of stone is a solid, foolproof way to nail down unity in a rock garden so you can garden with shameless taxonomic plant-lust for ever after and get away with it artistically. 

But what if you don’t have a large area or the luxury of truckloads of rock? You have a few other choices. The unity doesn’t have to be the species of plants- it can simply be their form or color. For instance, you could unify a rockless garden of rock garden plants by repeating the bun-form: seventy different species, never two of any type, say, of Acantholimon, mesemb, cactus, Dianthus, Campanula, Eriogonum, Draba, Arenaria- but all with that same half-dome form. They will have an undeniable harmony and familiar resemblance, lend the garden a very solid, specific feeling, while providing a total buffet of botanical eye-feast and brain-treat.

Crevice Garden at Denver Botanic Gardens

I think I’ve barely begun to let myself think of ways to extract variety and calm, the purveyors of excitement and peace in a garden, and make them happy bedfellows. Wouldn’t it be wonderful to be able to garden with not only plants of the rarer beauty in nature, but to create spaces that evoke natural landscapes of rare beauty?