This section is from the book "The Gardener V3", 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.
What a blank there would be during the dull winter months in our greenhouses and conservatories, had we not this brilliant and most useful flower to fall back upon during this period of the year! Not only is the Chrysanthemum useful in the decoration of greenhouses, but few flowers stand so well when cut; and therefore where cut flowers are in demand in quantity, the Chrysanthemum supplies a want that would not be easily filled up otherwise.
The Chrysanthemum has also the merit of being easy of cultivation, and, like many other florist flowers, has undergone a vast improvement during the last ten years or so, many of the Japanese varieties especially being very beautiful, both in regard to variety of colour and size of flowers.
There is a great diversity of opinion among gardeners as to what is the best time for putting in the cuttings. Some recommend November, while others again affirm that February is the best time. We are of opinion, however, that the time for putting them in depends very much on the purpose for which they are required, - whether for large specimen plants to produce large quantities of bloom, or plants to produce merely a few extra-sized blooms for exhibition purposes. If large plants are required, then we should put in the cuttings by December at the latest: 6-inch pots are a very suitable size to put them in. Prepare them in the usual way by draining well, and then fill three-parts full with any potting-soil, finishing off with pure silver-sand, as it is not intended they should remain long in the pots after being rooted. Two, three, or more varieties may be put in each pot, according to the number of plants required; only there should be a considerable margin left for casualties, and when potting them off the best can be selected.
When the cuttings are inserted, water them through a fine rose, and stand the pots in a warm pit. It is not necessary that they should be plunged in bottom-heat; but of course where a moderate heat can be supplied this way, it will hasten the process of rooting. Give an occasional dewing with the syringe at shutting-up time. As soon as they are nicely rooted, pot them up singly into 3-inch pots, in moderately rich soil, with a good dash of sand to keep it open, and place them in a pit where they can enjoy a night temperature of about 60°, with proportionate increase during the day. Keep them well supplied with water; and after they have grown about 3 inches, pinch out the points to make them branch out and form good stools - the laterals to be again pinched after they make three pairs of leaves. When the roots have reached the sides of the pots, they will want shifting into larger pots: 6-inch pots should be used for this shift, and the compost to consist of one-half of good fibry loam, the remainder being made up of one part sharp river or silver sand, one part of leaf-mould and one part of well-rotted dung, or bone meal. In potting, ram the soil pretty firmly about the ball, as there is less risk of it turning sour if firm.
When they have well taken with this shift, they may be removed to a cooler house, still keeping the points pinched out as they make three pairs of leaves. About the middle of May they will require another and final shift into the flowering-pots, which may be 8, 9, or 10 inch as desired, using the same kind of compost as at the last shift, only it may be somewhat rougher, and a layer of old dung may be put over the crocks: ram the soil firmly into the pots, and plunge them out-of-doors in a sheltered place. They may be pinched for the last time about the end of June, and must be attended with water when required; and turn the plants round occasionally, as well to let them get the sun equally on all sides as to break any roots that may find their way through the drain-holes of the pots. If they are allowed to make roots in this way, they may receive a check when they come to be housed, and then lose their bottom leaves: nothing looks more unsightly than to see them with long bare stems. They will require to be supported with stakes, so as to prevent them being broken with wind.
After the flower-buds begin to show, they will receive much advantage from a watering twice a-week with manure-water; and nothing in this way is better than good Peruvian guano, steeped, and then a little poured off into the watering-pot as you require it, merely colouring the water with it. They will require to be housed about the middle of October, and a few of the most advanced may be put into a gentle heat, when they will soon come into flower.
We have been speaking of plants for general decorative purposes, as being those most generally grown - those grown for exhibition purposes being managed in some respects somewhat differently. For this purpose the cuttings are quite soon enough if put in about the beginning of February. The cuttings should be put in in the same manner as described above, but the pots must be plunged in a hotbed or other place where a bottom-heat of about 80° can be had. When rooted, pot off singly in 3-inch pots, and after they begin to grow pinch out the points, but after this they need not be pinched again, the object being to throw as much vigour as possible into two or three stems. Of course they grow very tall, and we have seen them from 5 to 7 feet high. They must be kept growing, and shifted into larger pots as they require to be moved. Pot firmly, and they may be plunged out-of-doors in a sheltered place, as described for the others. Keep them well supplied with water, and securely staked: when the roots have pretty well filled the pots, give manure-waterings. They must be housed early in October, and pushed forward or kept back according to the time they are wanted.
When the flower-buds appear, they must be thinned out, leaving only two or three on each shoot.
We have seen the Chrysanthemum turned out of the 3-inch pots into a moderately rich border, and potted up again in September; but unless very carefully done, and kept close and shaded for a time afterwards, they are apt to lose a large portion of their lower leaves.
Nice dwarf plants, useful for front rows or for vases, may be grown by putting in cuttings in April, and treating them in all respects like the others, only keeping them in 4-inch pots, and pinched in to make them dwarf and bushy. J. G., W.