Saturday, May 30, 2020

A new Crevice Garden in Vail

Many gardeners are deeply familiar with the small yet rich, dramatic, and beautiful Betty Ford Alpine Garden just off of I-70 in Vail, CO.

It was the first place I saw a crevice garden- a small, low feature, but it still stuck with me.

The stinging  Caiophora coronata in their alpine house.

Now, working for their curator Nick Courtens, I got to collaborate in putting in a new Caucasus Mts themed Crevice Garden.

We used around 15 to 17 tons of surface sandstone harvested from far southeast Colorado.  We also used a silty soil mix with a little compost and a a lot of chipped gravel to help lock it into the deep crevices we created. The largest stones weighed a bit over a ton, and these were brought in by small front-end loader and mini excavator. A one-ton sandstone boulder is much larger than a granite one.

I tried to challenge myself in a few ways with this- to use forced perspective to make the garden appear even deeper and longer than it is by placing the largest stones closer to the main path.  We also integrated steps for a bit of a goat path that connects visitors to a small forested path up slope in back and the nearby Japanese-style contemplation garden with its iconic "floating rock."  I loved the "goat paths" in czech rock gardens which allow the able-footed to embed themselves within the garden.

 (Socially-distanced!) Group photo courtesy of Nick
Our very mixed crew was wonderful, including Domenique from Colorado Springs, who provides the garden with its recent excellent sturdy concrete troughs (I have two Dom troughs myself) . His german background infuses him with a genuine european rock garden culture and we loved having his volunteer help.

In a similar effort to the Christchurch, NZ, design, here were were trying to incorporate a new exhibit into and existing garden, and so I used some similar strategies. We left large pockets of open soil between mounds to blur the line between crevice and open soil. We also created forms which look like giant boulders themselves so that there could be stand-alone mounds nearby and across paths that relate.  These softly rectangular shapes were inspired by the eroded rock itself, trying to suppress what might otherwise be the over-strong linear pattern of vertical crevice design in the context.

We built a wide variety of crevice sizes, from paper-thin ones formed by the mere texture of the rock, to 6" (15cm) wide slots.  Some are two feet deep. I expect for such deep crevices filled with a true silty soil, there will be wild settling next winter.

Of course, you can't put in a garden without hitting your main irrigation line and having to repair it.
And there must be at least one inconvenient rain.

"The Silk Road" Garden

The Betty Ford already has a handful of Floristically regional gardens- South Africa, Silk Road, and Himalayan, for example.  The Caucasus are not the most fashionable places where seed is hunted and flowers are celebrated right now, but they have been in the past. The Caucasus is the epicenter of the richest diversity in the bellflower family.
I myself even brought back Campanula petrophila seed from my time there exactly ten years ago.  I identified it using a volume of an old Israeli-translated "The Flora of the USSR" in the Denver Botanic's library.

Collin pays homage to the Czechs!
I expect Nick's newly implemented cold frames will provide the bulk of plants over the years for this garden.

Until then, treat yourself and visit to the ever-changing Betty Ford Alpine Garden.


Panayoti Kelaidis said...

"No comments?" How can that be: this is a monumental post! Your droves of admirers are falling down on the job!

I applaud Vail (Nicola and Nick are both exceptional) for roping you in for yet another project.

This looks to be a masterwork! Can't wait to see it (maybe this Sunday).

Bravo, Kenton. You are a champion for gardening, for Colorado and Mother Nature (not necessarily in that order!

LMGaudet said...

What a stunning work. thanks for the photos showing the progress. It's fun for us average crevice gardeners to see how the big installations actually go in!

Kenton J. Seth said...

Thanks, friends. I don't think there is a distinction between "average" crevice gardeners and public/big/pro. In fact, I think that home gardeners often create things that are higher quality than public spaces and in the case of Crevice Gardens, home gardeners are the driving heart of innovation for the style and technique.

Steve said...

I have not made it to Colorado yet but I'll have to add this location to my list of places to see. When you say you used a 'silty soil mix' how would you replicate it using commonly available materials? the reason I ask is that we are going to redo half of our crevice bed because we appear to have made a couple of mistakes when we first created it such that it is doing an almost glacial collapsing motion onto an adjoining pathway.

Kenton J. Seth said...

The collapse you refer to is a real common thing that must be addressed in most crevice gardens. There are several solutions. So glad to hear you are crevice gardening wherever you are!

1 (my tendency to use most) tighter crevices for steeper areas.
2 (perhaps most historically used in Czechia) is dam-like rocks or clay "pucks" spiked into places that wash out. D istributing some up higher in the "watershed" as well as the worst washout places is ideal.
3. crushed gravel mixed into the soil. 1/2 inch screen size (1.5cm) or a bit smaller is dig-able and can be used as much as 50% of the entire soil mix and still act like soil. Sometimes I mix in a handful of 1" or larger gravel to dirt that I know will be resting right behind a vertical slot that will want to spill out like sand from an hourglass, or as you describe well- like a glacial delta. the gravel tends to sort of lock together and create tiny dams and stop the flow-out from fizzures. A bit like tire sealant in bike or car tires.

By a silty soil, I mean that is was a "Topsoil," a commercially sold dirt whose textural components (which can be separated and measured with glass jar settling method.) Was mostly silt, the rest fine sand, and I don't think it had clay in it. Which by definition would make it a silty loam. A great texture for rock gardens in dry climates as we have found sands (soil-sized particles- small) and coarse builder's/concrete/play sand to be too coarse/dry and occasionally nutritionally empty.

I've been seeking out silt rich materials by carrying a glass jar and water around in my truck. I try to avoid having clay in rock garden mixes generally. Most towns and cities are in lowlands that are either clay or silt dominated. If clay is present in the only "topsoil" around, I've had to get creative and get that silt from products sold under all kinds of names and used for all kinds of things, and the top most available one has been the fine rock dust which is the waste from crushing to create landscape gravel. Decomposed granite is one of those. In Denver rock dust is called "breeze" and is sold by the color or what rock it was resulted from. Those have been nice sources of silt-sized particles when all available"soil" was clayey. I have been recently experimenting using rock dusts or decomposed granite alone as a rock garden "soil." So far so good.

You could make a mix that is mostly DG with a small handful (like <5%) of compost (if you are growing general rock garden plants and not super strange Penstemon/eriogonum which hate compost) and perhaps 1/4 of your mix crushed gravel. This would be a pretty good goldilocks mix.

Hope this helps.

Kenton J. Seth said...

Meant to put in this link, super useful super succinct soil texture science/tests for gardeners:

The Meadow Behind the Meadow said...

Dude. Dude. 👍👍👍👍👍👍

Kenton J. Seth said...

Thanks Meadow-meadow. You must build some crevice gardens down in Louisiana or Mississippi! No one will have seen such a thing; you'll make a helluva splash. They don't even have to be big.