VOLUME 14 :: January—October, 1952 Illustrations shown in ...

THE CACTUS AND SUCCULENT January, 1952
CULTIVATION OF SUCCULENTS
By W. DENTON, B. E. M.
Although these notes are due to appear in the January issue of our Journal, one has to think about the subject
well in advance of this date. I have never known such a late season for the flowering of stemless Mesembs. On
the 10th October I noted the following Lithops in flower : terricolor, peersii, verruculosa, helmuti, comptonii, fulviceps,
bella, karasmontana ; numbers of others have buds just appearing and I am afraid will not develop fully as they
must have sunshine to give of their best. The Conophytums are in bloom and make a brave show. The following
are full out on the same date : pellucidum, polyandrum, exertum, tumidum, notabile, wettsteinii, etc.
These are charming little plants that have a much larger colour range, comprising shades of pink, straw, deep
yellow and white. It is a pity that the Lithops do not give us a few different colours, yellow and white are the only
two ! know of in this genus. With me the Conophytums will be kept steadily growing through our winter till about
March. This does not mean that you should water frequently, but just a little in the fine spells we sometimes
get in our winters. They are making new roots now, a certain amount of the old rooting system having died away.
September is a good time to take cuttings of these. For good results, great care should be taken to see they are
trimmed right, numbers of the plants, after a few years, develop hard woody stems sometimes an inch long and
even more with the very old ones.
Do not attempt to plant your cutting with a piece of the stem attached to it, it may not root at all. Cut back
as close as possible to the growth, just leaving enough to give you a scar. You will find they root well in Vermiculite
or ordinary compost. I do suggest that a layer of sand should be used on top of the compost for cuttings to go
directly into. They will find their way down to the good material soon enough. Unlike most of the stemless
Mesembs., they are very shallow rooting subjects and do not require deep pots.
Lithops will go to rest directly after flowering with me and will remain dry till about next May. Another
interesting plant in flower with me at this date is Pleiospilos bolusii, this is rewarding me this year with eight flowers,
it is one of my favourites, having been in my possession twenty years and has four nice growths. I have had several
queries about the cultivation of this plant during the past season. It is very easy to manage and should be kept
perfectly dry while the new leaves are developing, they are doing so at the expense of the old ones. When these
old stems persist in the form of dried skins, that is the time to give a little water. Unlike some others in this
Family, there should never be more than two leaves present on each growth at the time of flowering. When in
full growth, two leaves coming and two going is the correct procedure. Pleiospilos nelii is a much more difficult
plant and not nearly so free flowering, or so I find it. It will, most times, throw a bud long before the old stem
has died away and this always appears on new growth coming, but still I never water this while the old stem is
green and succulent. My plant of this is a fairly large one and I have not watered it at all this year, because of the
four leaves present. In fairness, I should state that my plants are plunged in sand and frame grown and that I know
there is always a certain amount of dampness present under these conditions. I am not afraid of the plant dying
for the want of water, however, they do not mind a long dry spell.
Both these plants have been in the same pots three years now and are due for an overhaul and re-pot next
spring. I expect to find a certain amount of root bug present, they are very subject to this pest. It is as well, at
this time of the year, to go over the stemless Mesembs. and carefully remove any dead skins remaining on the plants.
A pair of blunt tweezers are suitable for this and care should be taken not to in any way injure the new growths.
My reason for this is, owing to our usually damp winters, these old growths sometimes absorb any atmospheric
moisture present and this is liable, in some cases, to cause rot at the back of the plants. In their native habitats
the atmosphere is always very dry and bright and, remember, they are out of doors and not under glass. On
imported plants you can often count seven or eight, or even more, old skins and this gives you a good idea of the
age of the specimen.
You will find this cleaning up of old plants a slow, tedious job, especially with a clump of the small growing
Conophytum types, but it is well worth it.
I know that numbers of people will be using paraffin lamps for heating small greenhouses this year in lieu of
electric tubular heaters which are subject to cuts in supply. These should be quite satisfactory if kept clean and
the wicks trimmed frequently. It is better to use two smaller pieces of apparatus rather than one large one ;
you can keep the flames low and avoid the drawing up of the flame in a sudden warm spell. It is a very bad business
to come out to look at your plants and find them covered with soot. This will only happen if you are running
them at top capacity.
In my greenhouse I have a forty gallon tank filled under the staging. I keep this filled with rain water which