Creating and Planting Significant Banks

Good point, I'll give it some thought, thanks.

I'm not worried about the Inkarho Rhododendrons (they grow just fine on Salisbury plain ), but the Japanese Acers and perhaps a Cornus or two, would prefer acid. Being as the banks are raised I might be able to use ericaceous topsoil in place on those

 

Do they stop releasing calcium carbonate? I seem to remember reading something about the "age" of concrete etc.

The pile has been in the corner of the garden for 5 years, I could do a pH test on the soil under the edge of it, and another test some yards away, and compare the two

 

Well the builder's rubble of old clay tiles, stone and mortar buried under a fair bit of my garden certainly bothers a lot of the plants here! With an ambitious project like Kristen's, and quite a bit of outlay on plants, I should think some basic prep would save a lot of potential heartache later on. But each to their own....

 

Are you sure that's the rubble? Do you mean that it's affecting the drainage or the ph of the soil?

My garden soil is neutral and most of my plants are not particular about the PH levels in the soil. I suppose if Kristen was to plant a lot of Acers and Rhododendrons then perhaps the rubble may adjust the PH slightly.

But then again as they are the retaining walls and not actually imbedded in the soil then any lime that would leach out may be very small and only in direct contact with the walls.

 

Its will be a lot of concrete, so even if only a small effect, collectively it could well be significant.

I don't know how big gabbions are - 2M cube maybe? and all the way along the length of the bank.

However, I'm thinking, they will be "at the back" (the side that needs retaining), and on the ground, and of course they will be free draining, so I figure that if I put a french drain under them (perhaps at their front edge) I can take that water away somewhere else, before it has a chance to leach into the soil below, and then sideways to where it might have more effect.

 

Good thinking, K If even hard water has a bad effect on ericaceaous plants, then a buried source of lime would be a real pain!
JJ...I suspect a bit of both. On the positive side, every time I dig a planting hole I add quite a bit to the stock of hardcore for making paths. Builders, eh?

 

The ones I have seen are roughly 12"-24" cubed. Although some can be taller

http://www.toolstation.com/shop/Landscaping/Screens Borders/Galvanised Landscaping Cube 300 x 300 x 600mm/d130/sd3226/p52672

Every time I dig up some hardcore it goes on a big pile of rubble in my garden. To be fair the pile is getting smaller and smaller as the years go on but I still find it a pain. I'm building a small mosaic pathway to my shed this autumn and hopefully I will stick some of the hardcore in there.

 

Thanks JJ, but I'd struggle to get my concrete rubble into something that size! the ones I had looked at come ins sizes up to 2M x 1M x 1M
http://www.pavingexpert.com/gabions_01.htm