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

28 THE CACTUS AND SUCCULENT April, 1952
CULTIVATION OF SUCCULENTS
By W. DENTON, B. E. M.
In the last issue of our Journal, in my succulent notes, I promised to discuss seed sowing as I considered there
was still time to obtain satisfactory small plants by those people who were not in the position to give the heat
necessary for a start in February. In looking up my remarks last October, 1 note that I dealt with this subject
rather fully, and so I do not wish to weary you with undue repetition. I am afraid there is very little I can add to
the general principle then laid down. In talking about individual plants I shall endeavour to explain how I slightly
alter the potting compost to suit particular specimens and genera.
John Innes general mixture is what I use and this is added to, and sifted, to suit the various families I am dealing
with. Any late sown Lithops from last year could now be pricked out in new containers. It is not possible to take
out the seedlings as individuals, the best way is to turn out the lot, making sure that the compost is neither too
wet, nor dry, but just at the right consistency for you to separate them without damage to the tiny tap roots. This
is not as easy as it sounds, and does require great care. One other point I have noted with these, it is a very tedious
job pricking out these seedlings and the tendency is to take out the largest and not trouble about the very small
ones. This year take the trouble to save a few of these very small chaps ; in lots of cases they turn out to be of
the most pretty markings and it does make a difference to the general collection when viewed as a whole.
Anyone who has seen a pan of thirty or forty seedlings, say of Lithops fulleri or fossulifera will know what I
mean, some are much nicer than others in the markings. The genus Titanopsis is one that I have been interested
in for many years and I note it is a very popular plant with members, so a few words about them may be useful.
I often wish that my growing conditions were better, surrounded as I am with smoky chimneys and closed-in
conditions in the heart of London, I labour with a great disadvantage as this is a plant that very definitely requires
clean air and bright conditions.
There are the following species : T. calcarea, setifera, fulleri, schwantesii, primosii, luckhoffii, triebneri (hugoschlechteri
syn. astridea) and one I had sent me years ago called renoforme that I have not since heard of. They will
stand colder conditions than most plants and certainly require an additional amount of lime in the compost. I have
examined many of these, in pre-war years, collected from their native habitats and imported here and have noted
that the soil attached is very loamy and sandy and powders up fine when compressed. Therefore, I consider that
mortar rubble from an old wall very suitable to add to our base compost. The sand used by builders for this purpose
is pit sand and that is not nearly so sharp as we normally use. Three parts John Innes and one part rubble, as above,
should be suitable. Ample drainage of lime stone chips should be provided and, when potting, sit the plant on
a base of sharp sand. They are summer growers and watering should be commenced about April and carried
on with until after flowering when they naturally go to rest. Dry all the winter please for these. The most
popular one is calcarea, this is by far the easiest one to cultivate and makes a very pretty specimen, especially when
you have the true variety and not one of the hybrids so frequently met with. The others are not so easy. They
all grow well from seed and make nice plants in one year. I have had them in flower the first year and they nearly
always bloom in the second year. It is the winter that beats you with these.
T. hugo-schlechteri is one of the most difficult plants I have ever tried to grow and I have, up to now, never
kept one longer than three years. Last year I tried a new method, I potted this in a very deep pot, seven inches by
three inches, in the above-mentioned compost and grew plunged in a tray. I kept this in partial shade the whole
of last summer and I now have this plant looking fine and entering its fourth year. Perhaps, and I say this with
reserve, it may grow under the shade of tall grass or shrubs in its native home. I do not know, but such is my
experience with this. I should be glad to know how other people find this plant and expect to be found fault with.
I still have plenty to learn about all my members of the succulent families and would welcome any criticism as to
my methods of culture.
Special care should be taken with all Titanopsis plants, in watering never allow any to settle between the leaves,
they rot off very quickly.
Conophyttims should, about now, begin to change colour and you will notice they take on a purple hue at the
base, this is a sign they are going to rest and that the new growths are on the way and being nourished by the sap
of the old ones. Gradually dry off and keep dry for the next few months. About mid-July onwards they will
burst open the old leaves, then you can give a little water. Do not be in a hurry to start watering the Lithops,