Brendan Hughes

Yeah, yeah, more Alan Tichmarsh than Jeremy Clarkson, but I'll have a go anyway... If no-one here goes near a garden, maybe some chemistry experts can help.

I've got a pile of junk blasted off the side of my house - old lime mortar, I'm told. So I guess that makes it sand, cement, lime.

We've no council tip here so I'm getting rid of it by sieving it into some spare soil I have (loosest sense of the word - not black topsoil, but fairly thick red stuff), and spreading it on the garden. Ratio maybe 2 or 3 soil : 1 sandy "lime" mix.

Any reason why I shouldn't do this? I know sand will simply make a drier soil that drains faster, lime will make it more alkaline (though not much, from the proportions given), but I've no idea what set cement powder will do to plants etc. Pointless inert volume I can handle - actively killing/poisoning things is a different prospect.

It'll only be a couple of inches thick, so not exactly changing the soil type for trees etc, but I'd like to sow grass seed, so the top layer matters.

Any thoughts?

Cheers

SJ_Skyline

Ever considered fly-tipping?

alcazar

iTrader: (2)

Don't be daft, he said there's a fair bit. How's he supposed to get flies to move that much? And anyway, are flies even around yet............?

Alcazar

OllyK

My guesstimate - for what it's worth.

Lime mortar is porous to allow moiture through rather than it going in to the bricks and causing them to blow out when the water freezes (Yup my house is in need of some pointing ) However it is reasonably inert and isn't soluable (otherwise the rain would wash it away). So it isn't going to be much use for grwoing stuff in on its own as there will be no neutriants. If you mix it with a clay soil then it will improve the drainage. Either way I'd be tempted to mix it in well or top it off with some topsoil before laying turf. Also be careful round trees, if you build the soil up the trunck too much it can have an adverse effect and even kill them.

CharlesW

It depends on a number of factors.

What type of soil do you have at the moment?

What plants are growing or do you want to grow?

Soils tend to be more acidic than alkaline due to their content of organic matter. Where there are alkaline soils tends to be determined by the underlying geology. Alkaline soils tend to be thin as in not deep, and the flora somewhat limited. Think of chalk downs or the limestone pavements of Derbyshire. Much of the Mediterranean coast is limestone and so the soils are thin and alkaline. If the flora growing there is to your liking, you will be alright.

So making your soil excessively alkaline will definitely limit what you can grow.
Get a pH tester from your local garden centre. That way you can monitor what you are doing to your soil. Adding a lot of composted organic matter will help to counteract alkalinity.

OllyK

Feel free to correct me here:
I appreciate that adding lime to soil will make it more alkeline, however is not alkeline a disolved base. In which case a insoluable compound (lime mortar as opposed to slaked lime) isn't going to make much difference to the overall PH of the soil is it?

Brendan Hughes

SJ - I won't answer that question in public There are no flies on this user...

Olly, Charles - cheers for your thoughts, they're in line with mine. Unfortunately Charles has given me the same answer (ie more questions) that I already had from elsewhere, though the one other comment I heard was that to actually change a soil type needs a far bigger input than you'd expect - so I shouldn't worry too much.

I have a lawn of sorts already, I'm just raising the level by 3 ins and planting new seed (not turf) that is designed to grow in full sun, as my previous one pretty much died last summer. I can't say if the current one is on special topsoil or is in the "natural" soil, though I think it's the latter, so that bodes well. I intend to mix this stuff with bark chips which will hold moisture and also gradually rot and give a better soil.

I fully agree that it will be no added value, no nutrients - presumably if I fertilise it enough (after it's taken hold), that should be OK. What I'm really after is if it will actually harm grass roots. So far no-one's said an instant yes, which leads me to think the answer's no and I can go ahead...?

OllyK

I wouldn't put bark chips down if you are going to seed. You want reasonable soil, lightly compacted to put the seed on, the lightly rake over. If you put bark down it will be a long time before it rots, giving you an awful lawn in the meantime, which will be full of lumps and hollows when the bark does finally rot away. Your better going with a good organic mulch / compost / well rotted manure, bark will be around for far too long. I don't see why the mortar it should worry the grass, try finding somewhere were bloody grass doesn't grow!!

Brendan Hughes

No comments about my age please

I get your point. Still valid if I dig the chips into the current lawn - they're going to be occasional, 5-10 in a spadeful, I'm not putting down a 3in deep solid layer of chips - and then spread an inch or two of fine soil on top?

(starting to get worried that I bought 240 litres of chips yesterday...)

Flatcapdriver

Given that grass roots are fairly shallow, I wouldn't have thought there would be too much of a problem and as you're using grass seed (which is cheap) then if it doesn't work then your outlay is minimal.

It will need a fair amount of watering which should help to leach out the cement as well.

OllyK

I'd put them on the beds to keep the weeds down (makes you wonder how well your lawn will grow when they stop grass growing in the beds ), unless they are cocoa and you have a dog, in which case you should just dispose of them as they are poisonous.

If you really want to put chips down then go for it, let us know how you get on, I just doubt you'll find it as a recommended method in too many green keepers manuals!