On 25/04/2014 13:11, Indigo wrote:
I've got several quite old terracotta pots that were given me by an
elderly gent who'd once been a market gardener. They all have single
good drainage holes and I normally put a flattish stone or a bit of
broken pot or polystyrene packing in the bottom, mainly to stop compost
falling straight out or washing through, rather than for extra drainage.

Saw this: http://www.bbc.co.uk/news/blogs-maga...nitor-27126160
and wondered if I should really try something else - bit of old cotton
cloth or something? Used tea-bag?

This article from last year by biologist Ken Thompson is on the same theme:
http://www.telegraph.co.uk/gardening...otty-idea.html


So do you crock or not?




I don't crock all the time, certainly not in plastic pots with small
drainage holes, but usually in terracotta or ceramic pots with one large
drainage hole. I use shaped crocks rather than flat crocks, as the
latter really would impede drainage. When I run out of shaped crocks, I
put a layer of wine bottle corks in the bottom. These seem to give good
drainage, but are lighter. They also mean I can use less compost.

The only time I had a problem with crocking was years ago when I didn't
have crocks (hadn't broken many pots then!), so I used pieces of broken
slate from the garden. Of course this was too flat and blocked the
drainage hole. I lost the plant and learned the lesson.

--
Spider.
On high ground in SE London
gardening on heavy clay