This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
No time is better for putting in Geranium cuttings to strike root than from the first up to the third week of the present month. It is not always convenient to get them in just at this period, but it is worth a little extra trouble trying to do so. Cuttings put in now strike root quickly, and are well rooted long before the winter sets in - one of the greatest helps in wintering these plants cheaply and successfully. In order to save the bloom in the beds as far as possible, it is best to cut always above an open flower-truss; and as Geraniums strike better for being cut under a leaf-joint, this is also done at the time the cuttings are taken. In seasons like those we have lately experienced, it will be found advantageous to allow them to lie in a cool shed, that the extra sap may be dispelled somewhat before planting them into boxes. Twenty-four hours is long enough to let them lie thus. Then as to their size, I confess I like big ones. I have seen several lots of plants this season which were not so large, after Laving been a few weeks in their flowering quarters, as our cuttings were last autumn when taken off the parent plants.
I know there is want of room pleaded in such cases, but one large plant will go as far, and be much more effective than four small ones, as it takes the latter several weeks before they attain to a flowering size; whereas large plants, on the other hand, are effective at once. Another point worth paying attention to in taking cuttings from the plants in beds is this : in removing the points of shoots in a haphazard manner from the plants, you not only saddle yourself with a lot of small plants which are difficult to winter, and which take a long time to grow to a decorative size after being planted, but you also to a certain extent damage the plants materially, if you look for a continued and late bloom. By selecting large cuttings, and in the process giving your plants a judicious thinning, you allow the plants room for the development of a thin crop of shoots, which will carry the blooming season on as late as the state of the weather will allow. Geraniums are, in the colours in which we have them, by far the most effective dwarf-growing plants for massing purposes; and the time they continue in bloom under ordinarily good treatment is so long continued, that any slight trouble is always worth taking in their case.
I do not know that the large - trussing varieties are as good bedders, especially late in the season, as are older sorts with smaller flower-trusses. Any sorts I have tried have shown a tendency to damp off in the centre of the truss long before the outer pips were past, giving either an appearance of dirtiness to the whole, or causing the loss of a good deal of bloom if all such trusses are removed. Vesuvius, taking all points into consideration, is about the best bedding Geranium of the day. Its comparative hardiness is also greatly in its favour. Last season, when other sorts had been greatly damaged by frost, this variety kept on blooming for a long time. Unfortunately the sports which have been obtained of late years from Vesuvius have been of no value in any respect. Should a clear or bright pink or rose sport turn up, we would doubtless obtain an acquisition.