Repotting & Potting-on
What can be said
on this subject without offending someone. It isn't quite in the realm
of rocket-science, yet it probably is a major contributor to good flowering
and a component of success on the show-bench. It therefore deserves our
On the subject itself, there are broadly three bodies of opinion. One favours re-potting in
the Spring, before growth starts up again. Another re-pots at any time except when in flower or bud.
The third group, which includes mesembrianthemum, lithops, conophytum, etc, favour the middle
of the rest period and are particularly sensitive about the moisture-content of the compost
they use as one that is too moist may trigger the plant into early growth.
A popular test is to use a small dibber to estimate how dense the compost
is. Failure indicates the need for re-potting. Otherwise, the process
itself varies, and invariably it will involve new compost, well over half
of the old one being replaced. Care should be taken to use a mixture appropriate
to the plant, and with adequate fertilisers. (See Compost).
For example, some mamms may like a bit of lime, whereas epiphytes and
jungle succulents probably would not. If a new, or larger pot is involved
the latter is often called 'potting-on' (see below). The root system is
examined for 'root mealy bug' pests, or any other soil-dwelling pest such
as certain larvae. Special treatment is then required. See Pest Control.
Otherwise, dead or damaged roots can be trimmed away. A top dressing may
have fallen away when the plant was removed from its pot and it is an
advantage to remove some of the top remaining compost in case any bug,
eggs, or larvae are lurking there. The old compost may be shaken away
from the roots. Further root examination may reveal problems such as rot
or pests. Some growers give the plant roots a good wash in a fungicide
solution such as 1% copper sulphate, or Chinosol.
Potting-on - normally the root-ball is not disturbed as much as in re-potting. Almost always,
potting-on involves a larger pot, otherwise it is just re-potting. It is wise to use new
drainage material. Place some new compost on top of the drainage material, place the plant
on it, and dribble new compost into the gap round the side of the pot. Add new top-dressing
and the job is done.