On Jan 11, 8:39*pm, Adam Funk wrote:
http://www.guardian.co.uk/lifeandsty...wives-tales-ga...
orhttp://gu.com/p/2yyd7

This was the one that shocked me:

* Crocks in pots improve drainage
* ...
* False: a drainage layer in the bottom of pots reduces the volume of
* soil available to plant roots. Don't add gravel or crocks, but
* ensure pots have drainage holes.

This was what we were taught when pots were made from fired clay and
had just one hole in the bottom, by placing crocks over the hole you
reduced the risk of the hole becoming blocked by lumps in the compost
which was made chiefly of seived loamwith added sand, later peat was
added esp when the John Innes Institute came up with their recipe for
seed, and potting composts.
With the introduction of plastic post you started to get 4 holes, and
gradualy the number and size has increased and a small intermitent rim
was introduced to stop the pot forming a seal on flat surfaces.
There are times when I still put coarse peat or bark chippings in the
bottom of large pots that are going to be sitting on the ground as I
believe it helps to prevent water being syphoned into the pot and
causing waterloging and thus stagnant compost.
David Hill