purpletigron: In profile: Pearl Mackie as Bill Potts from Dr Who (Default)
purpletigron ([personal profile] purpletigron) wrote in [community profile] permaculture2009-10-26 04:57 pm

Garden archaeology

I have started my Autumn digging.

You would have to know that I am very much inclined toward 'no-dig' gardening to realise that this is odd. But I am converting our grassed area into raised growing beds, so I need to dig out all the creeping grass, bindweed, creeping nettles and so forth.

However, there is an added wrinkle. We know that there is some kind of rubble layer about 1 ft below the grass. As far as we can tell, this is because a former owner of the house demolished some kind of brick outhouse with glazed windows and corrugated composite roof.

So, today, I started digging out this layer.

In half an hour, I filled two rubble sacks with an unpleasant mixture of concrete, broken glass, brick fragments and all kinds of other rubbish. This from an area about 2 ft square.

I can see that I will spend all winter digging! But I'm happy to be bringing this patch of ground back into good health.

Has anyone reading experience of a similar situation? I understand that mortar residues can adversely affect plants due to pH changes. Given that I don't believe there are any heavy metal or organic chemical contamination issues, am I likely to get on OK growing on this ground otherwise? I plan to add back lots of municipal composted green waste.
watervole: (Default)

[personal profile] watervole 2009-10-26 09:39 pm (UTC)(link)
Mortar will raise pH. I have this problem with raspberries close to my house. Check the pH with a meter after you've dug it all. Add sulphur chips if the pH is a problem - or grow brassicas...
caomhinmaca: (Default)

Recollections

[personal profile] caomhinmaca 2009-10-27 09:56 pm (UTC)(link)
From work on my parents garden post-removal of an air-raid shelter, once you get the glass and mortar out as far as poss I found that (small) brick fragments go away quite quickly with frost.composite roof might be more of a problem - glass-reinforced? Asbestos?

I was finding glass in that soil for years though... None of it stopped me feeding a family of 4 for veg almost completely. I-d buried a lot of composted stuff and turf though, so the composted green waste plan is good!