Glacial Till Rock Garden

[cohan]

i'm not positive i have the right terminology, but near enough anyway:
i'm looking for inspiring examples of what i can do with my available stone, which is a highly mixed remnant of the glaciers in this area--which usually crops up to varying degrees in fields etc, ranging from gravel size to lots of comfortable two-handers, on to (occasionally) some boulders only for the skilled or well equipped to move, and in my case, a few pieces that i can just move, without developing a new skill set...
they are all smooth edged, like river rocks, (not angular recently broken, generally, but stones that have likely been moved hundreds of miles or more by the glaciers) with lots of quartzite (weathered to various shades of off white, tan etc), granite (the red and white sorts, mainly) some chunks of sandstone (which are flattish, and distinct enough i may save them up for separate use) and bits of other things..

take a look at some shots i took near the columbia icefield, and you'll get an approximate idea of the mixing of stones, my mix is likely even  more diverse..
http://www.srgc.org.uk/smf/index.php?topic=3923.60
starting at reply 67;
i guess this is more or less a scree or perhaps more moraine setting? i could do something similar in my garden, though i am thinking of more of the larger stones nearer together, with areas of more gravel around/through (the most common gravel here, eg on the roads, is a similar mix of stones, in fact you can walk along a gravel road here and find all sorts of interesting pieces)..

i already have some of my own ideas-debating the degree of randomness of distribution (of course totally random in nature in this type of stone deposit) vs groupings of similar types and sizes of stones-probably will do some of both..
but i'd like to see any existing-stone intensive- rock gardens that have been made with this type of stone, or any interesting natural plant communities in this sort of mixed stone..

i've been searching the internet and this site, but haven't yet found anything like this...

[Darren]

Hi Cohan, we are on a kind of glacial till too, limestone in our case. The stone was mostly buried under thin topsoil but there is just further broken stone underneath, from rounded boulders down through pebbles to sandy material. Drainage is excellent. The central feature in our garden is a sort of dry streambed cum path, in which are planted numerous alpines. We simply took off the topsoil and distributed the more photogenic larger stones on top of the subsoil. Silver and kabschia saxifrages do extremely well planted so their roots go down between the pebbles. Mossy saxifrages are seeding around nicely too, even in full sun - their roots are under the cool pebbles. I will try to post some pictures.

[cohan]

Hi Cohan, we are on a kind of glacial till too, limestone in our case. The stone was mostly buried under thin topsoil but there is just further broken stone underneath, from rounded boulders down through pebbles to sandy material. Drainage is excellent. The central feature in our garden is a sort of dry streambed cum path, in which are planted numerous alpines. We simply took off the topsoil and distributed the more photogenic larger stones on top of the subsoil. Silver and kabschia saxifrages do extremely well planted so their roots go down between the pebbles. Mossy saxifrages are seeding around nicely too, even in full sun - their roots are under the cool pebbles. I will try to post some pictures.

thanks, darren, i look forward to seeing some photos of your garden; although i have little to no limestone (possibly dolomite pebbles..) i think the look of a streambed is one of the things i may be able to do..
 my case is a bit different, in that we also have a deep soil and subsoil, mostly clayey, with a variable grey wooded soil on top on most of the area i will garden(more humusy areas in wet spots etc, but thats not where i am gardening, mainly)--the stonier till is not a surface feature right here (there are occasional gravel hills in the region, but not on my land, unfortunately!)..

so what i have is a fair pile of rocks brought to the yard over the years, mostly removed from cultivated fields-they tend to work their way to the surface, and some fields need repeated stone gathering; digging in my soil will produce occasional stones, but not enough to be of any use..
using what is at hand, i will probably shape the soil itself (by removing soil from areas to be made lower/wetter,and piling in areas i want to be higher i hope to create moister zones and higher 'peaks'!) with rocks worked into and above that..
i know that doesnt exactly follow standard rock garden construction, but the idea at this point is to use existing materials as much as possible for reasons of economy; excess water is rarely an issue here, and the beds in question are at the higher and drier end of my property, so while i will fiddle more with the substrate in particular planting zones of the rock garden, i'm not worried about having a lot of clayey soil below it, and i'd rather mainly keep the stones i do have in the visible zone and just below where the plant roots may need them...

[David Sellars]

Hi Cohan:

We are located in the Lower Fraser Valley and garden on what geologists like to call "boulder clay" - basically a glacial deposit of clay with irregular slightly rounded rocks much as you describe.  Our solution was to build our rock garden beds on top of the clay.  We used mostly sharp sand as we have very wet winters, mixed with some peat to provide a bit of humus.  Some of the beds are pure sand and the saxes and some Androsaces seem to like it.

Regarding rock garden design with boulders, my view is that much of the natural habitat of alpine flora is on talus slopes, glacial moraines and shattered rock outcrops with often not much evidence of stratification.  So it is quite feasible to build a crevice garden using boulders where the emphasis is on the chaotic aspect of nature rather than a more formal sedimentary look.  While the use of sedimentary rocks to resemble a rock outcrop is the standard and elegant method of rock garden construction, a natural rock garden can also resemble a talus slope or moraine, which are the primary natural habitats of alpine plants. We are fortunate to garden on a slope which makes it much easier to create a talus and moraine rock garden.  Plus we have lots of boulders!  Here are some photos of our front yard:

[cohan]

thanks for these examples, david..
certainly the plants are looking fantastic, they clearly like what you are doing!
so where exactly are you in the fraser-would that put you at around wet zone 7-8?

[David Sellars]

Hi Cohan:

Yes we are in USDA Zone 8,  not far from White Rock.  A nice Pacific frontal system has just come in warming things up and drenching everything. While our winters are wet, summers are often quite dry but not too hot, so saxifrages do well here.

I originally tried to build a stratified rock garden ten years ago using our boulders but gave up. Then I noticed that most alpines in the mountains don't grow in stratified rock anyway - so that gave me the excuse to build a chaotic rock garden.  I condensed my thoughts into an article for the NARGS Quarterly a couple of years ago.  A copy is attached.

[cohan]

Hi Cohan:

I originally tried to build a stratified rock garden ten years ago using our boulders but gave up. Then I noticed that most alpines in the mountains don't grow in stratified rock anyway - so that gave me the excuse to build a chaotic rock garden.  I condensed my thoughts into an article for the NARGS Quarterly a couple of years ago.  A copy is attached.

thanks for the article-i'm ornery enough to do my own thing even if i didnt find anyone else doing it, but nice to see some examples...lol
i'd be interested in seeing the Gwen Kelaidis gardens too, any idea if they would be online anywhere?

[David Sellars]

Glad to hear someone is as ornery as me. I like to experiment to see if something different will work.  Much of what is written in text books is regurgitating practices from the past without much new insight.  Reginald Farrer was a great guy but he has a lot to answer for!

The only place I have seen the photo of the Gwen Kelaidis berms was in the NARGS book: Rock Garden Design and Construction published by Timber Press.  If you Google the book title you get a Google Books result and you can click through to the Contents and navigate to the chapter by Gwen Kelaidis.  The photo is on page 72.

[cohan]

Glad to hear someone is as ornery as me. I like to experiment to see if something different will work.  Much of what is written in text books is regurgitating practices from the past without much new insight.  Reginald Farrer was a great guy but he has a lot to answer for!

The only place I have seen the photo of the Gwen Kelaidis berms was in the NARGS book: Rock Garden Design and Construction published by Timber Press.  If you Google the book title you get a Google Books result and you can click through to the Contents and navigate to the chapter by Gwen Kelaidis.  The photo is on page 72.

well, there are many many kinds of rocky environments, so why not many kinds of rock gardens?
the stratified type can really look great, but not realisitic with the rocks i have for now.. longer term, it would be nice to do a number of different things..
some cactus growers i know use straight road gravel--the type with fines and clay mixed in--and i think this would be a great material as a 'berm' /moraine, in particular for many species from west and south of here in dryish environments...

i'll keep my eyes open for the book...

[Diane Whitehead]

The Western Winter Study Weekend is in Medford Oregon the first
weekend in March.  One of the open rock gardens during a previous
study weekend there would interest you - on a ranch, lots of spiky plants.
I assume it will be open again this time.

[cohan]

sounds interesting.. i sometimes forget about the dry parts of oregon and washington, like b.c., i guess, wet coastal areas, drier interior..

i was just noting your average precipitation, which isnt as high as i expected it to be-if i'm remembering correctly, toronto's precip is over 800mm
-the town to the west of me (32km) is around 535mm total precip, and the city east of here (64km) is 482mm, so i guess i should be somewhere between. the precip goes down as you go east, away from the mountains..

[Maggi Young]

Cohan, here's a link to some from GK in Jane McGary's book, as David suggested above.......
http://books.google.co.uk/books?id=aHLFIGoERqIC&pg=PA71&lpg=PA71&dq=Gwen+Kelaidis+gardens&source=bl&ots=5cYx1nov3n&sig=K8-SZ7RQ5ejLCUJ020o-ZvvrutE&hl=en&ei=eEo_S77YO5_20wTHr9XRDw&sa=X&oi=book_result&ct=result&resnum=4&ved=0CBMQ6AEwAw#v=onepage&q=Gwen%20Kelaidis%20gardens&f=false

[Luc Gilgemyn]

You have a great looking rock garden David !!
I'm sure it provides the right habitat for lots of flowers !
I love it !
Thanks for showing !

[Gerdk]

Interesting discussion - but please: what is a ' stratified ' rock garden?

Gerd

[cohan]

Cohan, here's a link to some from GK in Jane McGary's book, as David suggested above.......
http://books.google.co.uk/books?id=aHLFIGoERqIC&pg=PA71&lpg=PA71&dq=Gwen+Kelaidis+gardens&source=bl&ots=5cYx1nov3n&sig=K8-SZ7RQ5ejLCUJ020o-ZvvrutE&hl=en&ei=eEo_S77YO5_20wTHr9XRDw&sa=X&oi=book_result&ct=result&resnum=4&ved=0CBMQ6AEwAw#v=onepage&q=Gwen%20Kelaidis%20gardens&f=false

thanks, maggi--you spoil me, i hadnt even got around to searching yet

gerd-- it refers to things like the popular crevice gardens, and other traditional types of design where the rock appears to be in layers