Troughs

[Ragged Robin]

Just a thought - surely the irregularity of sharp grit is the key to roots being able to grip in Alpine plants, at least, as rounded surfaces are more slippery and difficult to move over as per walking on a pebble beach 

[cohan]

i was also wondering: since we ARENT usually planting in pure aggregate, and we know that smaller particles will fill in between larger ones, could that be where irregular pieces end up having an advantage? --that is, in not filling in so evenly, the rough surfaces hiding some air pockets, where small particles might more easily find the evenly spaced spaces between smoother particles?
just speculating, havent tried any experiments...

[Paddy Tobin]

An excellent, well-informed and, certainly, very interesting discussion on troughs and composts.

Let me add a further thought/question: Has anyone given any consideration to layers in the compost. By this I mean I have in mind that the bottom part of the trough, or planting area, should have a mixed compost - a mixture of whatever you consider suitiable for your plants, grit, humus, leafmould or whatever, and that this is the compost into which your plants will send their roots. Above this I suggest a layer of pure grit/small stone and that the plants are  planted into this layer with their roots just in contact with lower layer which contains the humus. This top layer of grit might be 6inches/15cm deep - I give this as a suggestion, not as a certain measurement.

My thoughts are that the main cause of death of many of the alpine plants is water around the crown of the plant and, surprisingly and seemingly in contradiction, many of these plants actually enjoy or demand a good water supply below the root.

In summary, plants are put into pure grit with their roots having access to a lower layer which contains the nutrients they require for growth thus their crowns are given the extreme free drainage they require while their roots can still access water and nutrients for growth. This, I believe, mirrors the growing conditions of plants naturally found in scree conditions particularly.


I recall reading a description by E. A. Bowles in one of his "My Garden in Spring/Summer etc" series where he described his construction of a raised bed where he actually had piped water actually running continuously deep under the planting.

Paddy

[Lesley Cox]

I think Robin is right because I've seen many times, roots clutching the sharp stones and clustering around them while with rounded ones, the roots seem to go straight down or to the sides (if in a pot.)

[Paul T]

The roots may be clutching the irregular stones more because they have a greater water holding capacity as well.... i.e they're drawn to the water in the nooks and crannies on the irregular stones.  Rounded stones are smooth, so they don't hold water (if you know what I mean), whereas the irregular stones have holes/angles/ etc that hold water within them, which is then available to roots at a later point.  The irregular stones give good drainage capabilities, but also do hold water in a way that is available to plant roots.  It gives best of both worlds in that regard.  I think my memory from my old classes is correct.... it sounds logical anyway.    I think. 

[Katherine J]

I am just back from the Alps (the beautiful Ortler Group again), and catching this very interesting thread.

Anyway, prowling in the mountains, I've never seen rounded grit around the plants (except of in the streams)...

Paul, I think you have absolutely right, the plants do find moisture on the irregular stones. And they find also air pockets on it! I think, also Ian Young told this in some later log...

And Paddy has also right, they do root in 15-20(25) cm sharp, rather big (sometimes 1 cm or more) grit. I have sometimes dig holes in the scree, to see, what is deeper. The grit is more and more little, and more and more moist, sometimes even wet.
Ranunculus glacialis, for example, seems to live in pure sand, below the grit, but this sand is WET, especially now, in "spring". But that water is flowing, not staying in place.
I saw this year also Saxifraga oppositifolia and Androsace alpina, constantly flooded by RUNNING water from snow melting. And they flowered like mad.

And there are the crevices. They are extremely narrow. I see, that my two little crevice gardens made in window boxes (!) last year, worked very well in our hot summers, the alpines seem to enjoy life here much more, than in other "rock gardens" of mine with scree or whatever. They must not be watered so often, and also the drainage is good, at least the plants look more healthy like in other places.

[mark smyth]

The benifits of not working ....

[Paddy Tobin]

Too much time on your hands, Mark!

Still, a nice selection of trough to keep you busy planting. Enjoy!

Paddy

[mark smyth]

They are now filled with a woodsy mix for my miniature Hosta collection and other bits and pieces. I will also plant bulbs mainly Crocus no more than two species per trough.

[Paddy Tobin]

Mark,

Mary got a particularly nice miniature hosta this year - Blue Mouse Ears, I think it was called. It's nice.

She has a number in another trough and I can see her gathering more.
Paddy

[mark smyth]

I have over 30 miniatures including Mouse Ears.

Ian Scroggy here in N Ireland has an unbelievable selection of Hostas for sale from the biggest to the smallest. http://www.mailorderplants4me.com/catalog/33

I'll create a new thread to show the Hostas

[David Nicholson]

Being a retired 'gentleman' in theory I should have all the time in the world, but I never get round to making the troughs I have been promising myself to make for years now. Do you export Mark?

[mark smyth]

It's so easy David. I made another 3 on Wednesday and 3 today. Sorry I dont export but you will be able to get fish boxes from your local fish/reptile shop

[Lesley Cox]

Mark, why have you made one higher at one end than the other? If you don't place it so that the top is level (which would negate the slope), won't the water and compost work down to the lower end?

[Lesley Cox]

That is a very scrumptios hosta website. I wish....