Re: Fwd: RE: Packing Pellets and Plants

bridget lamp wrote: 
When I took Container Media at UC Davis, we were
told
that putting a layer of rocks or terra cotta shards
at
the bottom of the pot also impeded drainage.  There
was a demo in-class to show us, but it was awhile
ago
so the details are foggy.  I'm sure someone is going
to prove me wrong when I write this!  But, it's one
of
those old-wives tales or something your mom told you
to do when you were learning to garden in the
backyard.  And mom always knows best!

Actually Briget years ago I found when I had to clear any pot the crocks or stones at the bottom had invariably been invaded by lots of roots which extended right to the bottom of the pot. This led me to reason that it would be far more profitable for these roots to have an extra layer of good fertile mix to grow among, rather than those barren drainage materials and I began to leave out the drainage layer entirely, at first in all but the very largest containers (more of this further on). I must say though I missed the effect the crocks were having on drainage -quite the opposite of what I was aiming for of course.

One thing I at first found a bit tricky was the ease with which roots could grow out of the drainage holes and block them, but I soon got round this by lining the bottom of each pot with a small piece of plastic mesh, which in most cases not only discouraged the roots from trying to break out but also prevented a good part of the continual loss of fine (and even not-so=fine) mix through the drainage holes after watering.

This mesh also, as someone else mentioned discourages invasion by unwanted soil insects and slugs, and further to this I have mentioned I did for some time retain a small conventional drainage layer in large outdoor containers, but one particularly dry summer I decided to give some big pots a thorough soaking by standing them is a large shallow dish. This certainly did an excellent job of making sure the whole pot was moistened, but it had an unexpected extra result when I found a whole lot of slaters (pillbugs) drowning in the dish. When I looked carefully I was to discover these had not just fallen into the water trying to get a drink, but must have actually come out of the pot.

Closer investigation showed considerable caves excavated above each drainage hole right into the soil layer in most cases. It seemed that at that time the pots with their contents regularly moistened were a most welcome refuge from the generally dry and unfriendly soil and the creatures had ingeniously take advantage of it.

This finally encouraged me to take the plunge, leave out the crocks from these pots also and fit all of them with screens as well, and this I have done ever since with very good results on the general well-being of the majority of my plants. Any that have failed under the new regime I am confident have done this for reasons other then drainage problems anyway.

Mind you, I do from time to time have a probem which is the exact opposite of Carol's, a few of my large pots which happened to be plastic proving far to light to stay put out in our often gale-force winds and I have been forced to include some heavy rocks in the mix to keep the plant from tipping the whole thing over or even it simply blowing away pot and all!!

I have mostly got round this in recent years by gradually upgrading my pot collection so I now use mostly heavy ceramic pots outside and keep plastic almost exclusively for indoor plantings.

Moira

Tony & Moira Ryan,
Wainuiomata, North Island, NZ.     Pictures of our garden at:-
http://mywebpages.comcast.net/cherie1/Garden/TonyandMoira/index.htm
NEW PICTURES ADDED 4/Feb/2004

Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index