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.
For many florist's flowers, the next two months are particularly trying ones. Verbenas and Petunias, as cases in point, very often die off during this period. Much depends on having good established plants, as opposed to those which are struck late, and therefore wanting in vitality. In light modern houses there is not the same difficulty with these, as they keep growing with very little trouble. In old dark structures the case is materially altered, and a higher temperature is an absolute necessity.
Hollyhocks should have been lifted and potted up before this time, so as to have got well rooted before winter sets in. These should be kept in a slowly growing temperature, in order to supply cuttings for January and scions for grafting in February. Summer-struck plants are in 5-inch pots, and are also kept growing, in order to make stock in spring.
Dahlias have kept rather badly with us for the past two winters. It is necessary to look these over pretty often, more especially if any signs of decay are discerned. Pot-roots, for summer-struck cuttings, keep safely stowed away in cool houses, after the foliage has decayed.
Gladioli keep perfectly in a dry room laid out on shelves. I used to clean them; now I do not think this either to be a necessity or of advantage.
Pentstemons, Carnations, Picotees, and Pansies in frames should be kept open to the air at all times when rain and frost are absent. Those in pots should be plunged so as to cover the rims of the pots. No water is required during the winter months when thus plunged.
Zonal Pelargoniums are at this season more attractive than at any other time. Strong healthy grown plants in 5 1/2 or 6 inch pots, with the soil a simple one, and rammed perfectly firm, give grand results. They require manure-water to keep them healthy and the trusses large. A light structure, with the plants close to the glass and an even temperature of 55°, keeps them blooming very continuously. I find Pearson's varieties much the best for winter-flowering, or, perhaps, for any other season. Where white flowers are much wanted, White Vesuvius will be found an excellent variety. Under proper conditions the plants will require a good deal of water: the want of water is fatal to a continuous and fine bloom.
Chrysanthemums are just now at their best; we have them into February in good quantity, but just now the main supply is in. These cannot be too close to the glass. The matter of 7 or 8 feet distant is certain to render nugatory all the previous summer work. The work calling for most particular attention with these is to get the old stems cut down when done blooming, and to encourage the production of healthy cuttings for the next year's crop. I always put cuttings in as soon as they are large enough, and throw the old stools away. For specimen plants the cuttings should not only be put in soon, but the plants, when struck, kept growing sturdily. The freer pompons can easily be made into specimens 3 and 4 feet across; large flowering varieties sometimes exceed this size. The largest plants of these are formed from old stems, which are cut down to about a foot of the collar, and after the latent buds have either broken, or (if started when cut back) are sufficiently grown, the plants are shaken out and potted in 5-inch pots. These cannot be too firmly potted. Loam, fresh, flaky, and dry cow manure, with bone-meal added, suits them admirably.
Mrs S. Rundle, Mrs Dixon, Lady Hardinge, Prince of Wales, Venus, Her Majesty, are kinds easily grown, and seem to succeed with ordinary attention.
Primulas will be either in flower or growing freely. They will give no trouble if grown in small pots, in a temperature of 50° to 55°, and never allowed to become anything like dry.
A friend writes to me taking exception to plaster of Paris as a manurial agent. In our case it was used as a substitute for lime, and was most likely mixed up in some other form by the manufacturer who supplied the manure. Sulphate of lime is not so much esteemed in this country as in France, where it is thought a good deal of. In fact, like my friend, many consider its value as a manure a very problematical one. No doubt that ingredient may be left out, and also the nitre, which is said to be a difficult material to obtain of manurial value, and a mixture of sulphate of potash or muriate of potash, and sulphate of ammonia substituted. R. P. Brotherston.