"Phil L" wrote in message
. uk...
When I transplanted my onion seedlings a few weeks ago, I had no compost
ready to use and only a small bag of manure - I remebered digging
deep trenches for onions and leeks for my dad and
filling them with all kinds of stuff like manure, compost, newspaper and
anything else that was at hand, my only gripe was that onions seemed to
me
to send roots straight down from the bulb, therefore a trench was mostly
wasted.
I got a length of 4" plastic drainpipe about 4ft long and rammed it into
the
ground to about 20 inches, lifted out a core of soil and filled the hole
with a rich mixture of horse dung, compost and all manner of other
goodies
and planted the onions in that, they seem to be going like the
proverbial
clappers, and it only took ten minutes instead of a few hours....has
anyone
else tried anything similar to this?

This reminds me of the 'french' system-a highly intensive growing method-
where all the soil is prepared to a depth of upto 2 feet. As you say many
roots go downwards and I guess that the extra depth of cultivated and
composted soil gives any plants a good advantage