On Wed, 11 Sep 2013 12:08:41 +0100, Chris Hogg wrote:

On Wed, 11 Sep 2013 10:23:49 +0100, "T Bently"
wrote:

Want to transfer a few plants to big garden pots to keep them there for the
long term.

I was told a while ago that the composts you buy from garden centres do not
contain all the minerals found in ordinary garden soil, so even if you feed
the plants regularly they are still not getting all the necessary minerals.

Would this apply to a compost like John Innes No 3 ? Or should I mix the
John Innes half and half with ordinary garden soil? Novice grateful for
any advice.

All John Innes composts are loam (i.e. soil) based, with added peat,
sand and fertilisers as appropriate. For long-term potting as you have
in mind, JI3 should be fine, provided the plants you intend putting in
there aren't ericaceous, e.g. rhododendrons, azaleas, camellias,
summer-flowering heathers, and a few others, in which case you should
use JI Ericaceous compost.

However, any compost or soil in a pot, long-term, will lose fertility
and need to be fed regularly once the initial food reserve has been
exhausted. It's just that JI composts will retain their fertility
longer than some other types.

More info he http://www.johninnes.info/about.htm
and he http://www.johninnes.info/technical.htm


We have used JI3 for all our non-ericaceous container grown shrubs and
plants for more than 15 years and have found it be an excellent
medium. After a year or so carefully remove some of the top layer and
replace it with fresh (we use the 'exhausted' stuff in the base of the
deeper containers with shallow rooted plants).
--
rbel