He observes the rule of tight crevices where it's steep, and open pockets/loose crevices where it's level and more even. He is also a careful observer of keeping strata lines the same width the whole length of their run, which honors the nature of most sedimentary stone. He is using sandstone here.
Observe how there is a prevailing perimeter line, looking down at the bed, and one good stone is allowed to jut out beyond it. He knows when to put some variety amidst the harmony. Within these perimeter stones he creates a pocket, left, to plant in. The tight crevices on either side of the small stone are fair game, too. A similar pocket, above, has already been claimed by an Asperula, perhaps A. sintenisii
Another view of Alan Furness' crevice feature. See the repeated angles about...
He says the big moment for him which sold him on crevice gardens was seeing one in Northern Ireland, build by ZZ, which had him nearly fooled it was a natural outcrop!
He uses sifted soil to fill his crevices, like Josef Halda, the Kingdaddy of crevice garden history.
Alan has also been working with tufa, for decades. It's the finest way to grow Saxifrages in the open.
And shockingly, the Wyoming heartthrob to all bun-plant fans, Kelseya uniflora. Very impressive. In his climate, he grows is south-facing and on a perfectly vertical tufa face, outdoors.
He's also the seat of Celmisia diversity in the UK. Celmisias are a New Zealand daisy-family member with incredible leaves; they are relatively recent in common cultivation; I expect them to explode in popularity one of these days, I've killed one back home. Seeing his lot, I might just try again.
He complaints that the pheasants eat the baby plants just set out into the garden!
His home was once a chapel for a physician community.
Perhaps the part of his garden that spoke to me most directly was his moraine. In his garden, a moraine means the soil and aggregates are arranged such that there is a gradient of gravel and rocks on top to soil deep below, acheived by mixing in several inches of gravel into the soil, topping it with more gravel. Sound familiar? Like our layered-soil crevice gardens. Like the gravel gardens of Beth Chatto and the "Flowering Steppes" in Olivier Filippi's recent book which I ate up like a starving man at four course meal. (I deeply recommend it).
I also absolutely love the very natural randomness of the stone. It's artfully arranged, reminding me of Peter Korn's chuck-it-over-your-shoulder and then push-it-in-with-your-boot way of arranging rocks. That kind of design that is so good you don't realize someone did it.
The moraine garden is twenty years old, and is the "least weedy part of the garden." How is this so? the gravel is deep enough that there is no soil in between to let seedlings get started. New plants however, are planted and their roots are sent deep into the hole to touch real soil, while most of their necks is in contact with gravel. He says that as the years roll on, a soil is indeed slowly forming in it. It was meant mostly to accommodate Potentilla and Dianthus he said, but Collomia and Silene rock on this summer.
I think this is a lesson we could take to the intermountain west, where annual weeds are equally loathed but deep gravel also benefits us by conserving moisture. It's funny, because I had just read about this deep-gravel concept in the Filippi book, only to hear it from the New Zealand plant hunter Steve Newall (who recognized my trying it out at KAFM), and incidentally, Steve is responsible for supplying those Celmisias in Mr. Furness' garden! What a small world of gravel and funny kiwi daisies!
He appreciates the garden for its naturally low maintenance, which has driven how he guides the rest of the garden...
What does his other low-maintenence garden look like? See below.
Yeah. Take that. Bang.
What is low-maintenance about it? Dense plantings to exclude weeds. Dense and tall enough.
Alan opines that Brits, who are surrounded in nature my Heather (Calluna and Erica spp.) tend to have a "snobbery against them," since they are so common, but he says "how else would you have this much color in August?" He continues to say he likes "small, easy shrubs that just swamp the weeds."
I think that applies to us back in Colorado, eh? With our own native wee shrubs.
He says: "If there is a successful alpine in the UK, it is Heather."
A creative cut-in design here allows the gardener and viewers access to ground-level of the middle of the slope. You can get eye-to-eye with a snail here if you want, and the sense of space in the environment attracts you to walk into it, even though it is obviously a dead-end. He built it to create deep, cool shade in the wall to grow Gesneriads.
We are inspired by your watchful skill, Mr. Furness.