Considering that Copiapoas come from a habitat with
such an extreme climate, they are remarkably tolerant of pot culture in
Britain. Outlined below are the methods of cultivation which I have
arrived at, having grown a range of species over many years. It is
important to remember that most species are slow growing: it is foolish to
try and rush them. Although I suspect that cultivated plants are far
removed in appearance from their counterparts in the wild, it is still
possible to grow well-spined, shapely specimens, with patience.
The numerous collected plants offered in recent years
have generally proven quite easy to establish, although I have no
experience with huge C. cinerea specimens, which I imagine could be
more difficult as older plants often are. Given an open soil of peat or
gravel, roots are soon formed. I used to grow on in peat-based soils, but
found this caused problems in the longer term. Large pots stay wet for too
long, and all peat composts lose their structure and begin to clog if not
replaced frequently. This change of structure proves fatal to the roots,
and so frequent repotting is unavoidable. The work involved and the
detrimental effect on the plants’ growth of constant disturbance made me
look for a more permanent soil. The use of a mixture comprising mainly
gravel with John Innes compost, fertiliser and some peat/leafmould has
produced better long term results and saved time on management. Since many
species have tuberous roots, a large pot is often required and sharp
drainage around the neck of the plant is essential.
To obtain the best spine development, and the
greatest chance of flowers, a sunny locality in the greenhouse is
necessary. Care is needed to avoid scorching, to which Copiapoas seem
particularly susceptible. Plants near the glass are most vulnerable. In my
view, this scorching is caused by insufficient ventilation and excess
dryness at the roots. It can also be caused when plants are moved, or
turned round, into a position where they are suddenly subjected to direct
sunlight. Adequate ventilation, which often is not available from vents
alone, can be provided by a fan.
As long as the soil is very sharply drained, Copiapoas will take liberal watering during the growing season, but care
should be exercised early in the year with the soft-bodied species (C.
humilis, C. hypogaea, C. tenuissima, etc.) which might
split if overwatered.
Growth rates are often slow, so that grafting may be
considered. Although I am generally in favour of grafting as a method of
cultivation, I feel that it rarely produces a good Copiapoa. It
often, in my experience, causes the plants to elongate out of character
and produce weak spination. The best stock to use would probably be
Eriocereus jusbertii, but on the whole, I favour growing this genus on
its own roots.
There is a wide choice of species offered for sale as
seed, which with patience can be raised into fine plants. It is
unfortunate that many Copiapoas look identical in their early years, not
developing their individual characteristics until much later. Strangely,
the white covering associated with C. cinerea does not seem to
develop on seedlings, although imported plants continue to produce it in
cultivation.
Flowering of Copiapoas can easily be achieved in the
softer bodied, smaller growing species such as C. humilis, etc. Plants
such as C. montana, C. taltalensis, C. longispina, C. marginata and
C. megarhiza also will oblige without much problem. The hard-bodied
species around C. cinerea, C. dura, etc., can be rather less
reliable but flowering is still possible - more than can be said for that
outstanding species, C. krainziana, which has never flowered in
Britain to my knowledge!
