journal

April, 1951 JOURNAL OF GREAT BRITAIN 27
there were affected, but it was significant that every one of a number of Lemaireocereus pruinosus seedlings in
different parts of the house were all killed. With one or two other plants such as Astridia velutinum one plant
was killed whilst the plants next to it were all right.
I do not intend to repeat all the directions which I have given in the past as, if you wish to read about any
section of the growing year, you can easily refer to one of the back Journals where you will find articles in " Seed
Raising," "Re-potting," "Watering," "Taking Cuttings," "Frame Culture," and so on.
If you are unable to maintain a temperature of about 70 degrees, do not sow your Cacti and other Succulent
seeds but wait until the general warmth of the greenhouse increases to something nearer that level. I have sown
about 230 different kinds of Cacti and most of them are coming up well. One or two kinds are not up yet although
they have been sown for three weeks now, but I do not worry, they usually come up in their own good time. I
have found one bad point with my propagating frame and that is that I had sheets of glass laid on the top. The
water condensing on this was dropping back on to the seedlings and there is nothing worse to start an attack
of damping off than this. I then devised a sloping attachment to place on the frame which gave a four-inch rise
to one side. The moisture which now condenses on the sloping glass runs down without dropping on the seedlings.
I have made sure this season that the seedlings get some air at all times. It is fatal to have an air-tight enclosure
for these seedlings once they are up. You must provide some ventilation at all times, and not only during the day.
For the past few years I had been able to get all my plants re-potted before January was out, but this year it
has been so wet and dull that I did not think that it was advisable to move the plants so early. I therefore, waited
until well into February before starting and I have now just about finished ; and it took me nearly a fortnight
working every day and nearly all day to do this. It was apparent to me that it was beneficial to re-pot each plant
every year. In one or two cases I found that I had re-potted a few in July, 1949, as I always mark each label on the
back with the date of re-potting, I had not done these plants in January, 1950. It was only in one or two such
plants that I found any trace of root-bug. I have always said that the best way to cultivate root-bug (if you do want
it) is to refrain from re-potting a plant each year. The dead roots and overcrowded pots showed that it was high
time that most of the plants were moved. I do not always give the plant a larger pot, it depends on the type of
plant and the amount of growth which it has made as to whether it gets a larger pot or not. Of course, if no
larger pot is required the plant is never put back into the same pot, but is given a fresh, clean one. Of course, as
usual, I had an awful job to find room for all the plants once I had re-potted them. Some of them had made very
good growth although last season was not a good one for growth. One plant of Mammillaria bocasana (illustrated
in a back Journal), has grown to seven and a half inches across and is six and a half inches high. Of all the hundreds
of plants which I had handled, it was this one which I had to drop head down into the old soil and rubbish. It
can be well imagined what this plant looked like decorated with dead roots, soil, charcoal, etc., Still, the aid of an
old tooth-brush soon brought the plant back to normal.
I find that my Mammillarias are increasing in numbers as well as in size that I am already forced to part with some
of the other succulents I have raised from seed during the last four or five years. I had restarted my collection
after the war and did not imagine that it would be so soon when I should have to start parting with some. In
the first place I sowed seeds of any kinds that came to hand but now I have to be more particular and stick to certain
kinds only. Once the greenhouse gets near to capacity, one has to make up one's mind as to whether to specialise
in one genus or not. It is quite impossible in the averaged size greenhouse to hope to house a representative
collection of all the genera of Cacti and, when once the house is full, it is much better to consider carefully whether
you have any real preference for any particular genus. I do not suggest that you turn out everything but the one
kind, but don't deliberately add to the numbers of the plants except those which you favour. In time your own
special fancy will have grown to such proportions that it becomes imperative that you get rid of a few more genera.
Whatever may be said to the opposite, it is only by specialising in one or two genera that you are able to obtain
a really comprehensive collection, and it is, I feel sure, much better to be master of one genera than be a Jack of
All types. A man may have five hundred different Cacti in his greenhouse and have nothing out of the ordinary,
but if he had three hundred different Mammillarias he would have a collection not only very representative, but
something to be proud of showing his Cactus friends as well.
Watch your Lithops from now on as some will be ready for their first watering this year, before others. Wait
until the old stem has almost dried up before watering. This may be sometime in April, but as late as May in others.
The policy of placing chips of stone on the surface of pots containing Lithops is a common one, but it is often almost
impossible to see the state of the soil underneath, and so one cannot tell when a plant needs water. A better plan
if you feel you must have some stones on the surface is to see that the stones are around the base of the plant only,
thus leaving the rest of the surface exposed to view.
Meanwhile, " Good Growing," plenty of air, but steady with the water can.