Topic: Coffee Grounds

[Digeroo]

Our soil is very alkaline and tap water even more so.  tt does not affect the actual fruit but after a few years the plants simply die out.  I have not used manure because of contamination problems but they have had loads of recycling compost which I presumed was also acidic.  But when I checked it has a ph of 8.3 which is alkaline.  Maybe I can source some spent hops instead.

[pigeonseed]

That's a nuisance with the contamination of manure - yes try and get hold of hops, and I suppose you make your own compost and leafmold? I think they're acidic as well, but perhaps not enough to make a difference on your alkaline soil. But I suppose the best you can do is add lots and lots of organic matter.

I'd always have thought that compost from pine needles would have been ideal, except I heard on this forum about its growth inhibiting chemicals  :(

[Robert_Brenchley]

I don't suppose they survive once it's well rotted. Pine needles inhibit germination but they don't bother established trees at all. The interesting thing is that in a generation, a new conifer plantation can completely change the soil type, from a fertile, neutral or alkaline brown earth (the sort of fertile lowland soil most of us are used to) into an infertile, acid podsol, simply through the effects of the acid from decaying needles.

[pigeonseed]

That's a strong effect. But it sounds like when composted, they could help acidify an alkaline soil. They do rot eventually, my mum can't cope with the amount of needles and cones which drop on her garden from next door's tree and so they mound up and rot down eventually into a very nice crumbly soil.

[chriscross1966]

The growth inhibition is a short-lived effect, the acidifying one rather longer-lived, and the inhibitor is mostly for germination too...

chrisc

[pigeonseed]

If only you lived near my mum, digeroo! Her passive composting would match your alkaline soil situation perfectly  :)

[Digeroo]

What precisely is passive composting. ???

[Tonythegardener]

There is a lot of evidence that coffee grounds are well worth while putting onto your compost heap.  

http://www.puyallup.wsu.edu/~Linda%20Chalker-Scott/Horticultural%20Myths_files/Myths/Coffee%20grounds.pdf

There is little evidence that coffee grounds will deter slugs.  

There is some evidence that caffeine does have an effect on slugs, however I would expect that you have already dissolved most of that out of your coffee before it gets anywhere near your garden slugs.  Together with rain and general dampness of the ground, I would suggest that this is a very ineffective way of combating slugs and snails.  
Research in USA suggested that spraying a solution of 2% pure caffeine would prevent slug attack.  So don’t drink you coffee spray it on your plants and even then you cannot guarantee it will be strong enough.  Would caffeine be better sprayed around the plants or on the foliage?  Does caffeine have the same effect on British slugs and snails as those found in USA?  I don't know.  
This does not seem to be very viable for the amateur gardener and using the well tried and tested ways of gloved hand picking and beer traps will be the only effective way for the organic gardener.