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.
With August returns the season for propagating the stock of bedding-plants for next year's requirements, but this season it will be a simple impossibility to obtain cuttings from Geraniums so early without destroying all hope of a display of these for the season; while those of us who must leave the beds intact until frost cuts the occupants down, have no means of saving the old plants to make up to some extent for the want of young plants from cuttings. There will also be the quality of the cuttings to be taken into consideration in proceeding with their propagation, for unless the weather changes to a great extent these will be of the most watery nature, and difficult to manage under ordinary treatment. 1 would advise a particularly light open soil to be used in the boxes - at least a layer on top of such - and the cutting-boxes placed under the protection of lights, and shaded at first from severe sun. A week of such treatment ought to get the cuttings into a safe condition, when, if the weather be fine, shading and lights may be dispensed with, and the cuttings struck in the open. Should wet weather continue and signs of damping at the neck be noticed, the whole batch ought to be placed in a vinery or other structure where they can be safe and are certain to strike.
I have been thus particular in advising the above treatment, because a mistake so late in the season must result in a great deficiency in next year's supply. In the case of Verbenas, Iresines, and plants of a like nature, particularly in the north, it will be advisable to use a little heat, just a very little though, to get them safely rooted. Directly roots are produced, cold treatment must be given them to keep the plants in a dwarf and sturdy condition for passing the dangerous winter months. Those who strike them in July will have less bother than those of us who propagate later. Lobelias I find most certain, kept growing in pots through the summer; and as these are very useful for conservatory decoration in the summer and autumn months, and as a large number of cuttings is produced from one plant, a small number of pots is sufficient of these. Violas, Pansies, Pentstemons, and plants of a like nature which are kept over the winter in cold frames, do not require propagating till September. Carnations and Picotees layered in July should be potted up before many roots are made, and the plants induced to fill the pots with roots before winter sets in. Calling for great attention, from now onwards, is the keeping of beds and lawns in a state of great cleanliness.
No ribbon-border looks well unless the different lines are kept perfectly distinct one from the other; but when these are kept well defined, no mode of summer planting is more attractive than this. The lines ought to be picked over about once every ten days; plants like Perilla to be regularly pinched in, and Cerastium tomentosum and Koniga variegata to be clipped so as to be level with the grass at the edges. Where Festuca glauca and the tall-growing form of Dactylis glomerata variegata grow too tall for edgings, it will be necessary to go over the lines of these and pull the tallest of the blades entirely out; both are capital bed-ders. Lines of Violas, and those in beds either by themselves or mixed with other plants, will now require to have all the withered blooms and seed-capsules picked off, when they will flower persistently until the bedding-plants are over. Carpet-bedding will prove pretty much a failure this season. Even in the south up to the middle of July no growth had been made on Altemantheras and Coleus; on cold bottoms there have many of them dwindled away, requiring to be replaced if a satisfactory display is to be secured. Mostly for want of time, it will be impossible to do this.
Growers of Mentha gibraltarica, instead of cutting over the plants, will find it do better to pull out pieces entirely, pressing the remainder level. Pyrethrum, Iresine Lindenii, Coleus Verschaffeltii, and plants of a like nature, require to be pinched over at least once every ten days, allowing just the right space for the different lines, etc, and nothing more. Carpet-bedding, in any or all of its forms, owes its success as a system quite as much to high keeping as to beauty of plants or design: where it is impossible to keep the beds in order, no carpeting should be attempted. Autumn-flowering plants, such as Dahlias and Asters, will now be approaching to some state of beauty. Although not generally practised, the Dahlias do best kept thinned slightly out, and all old blooms as they become passee taken off. Asters require tying to stakes, and when too thickly planted for full development of the plants, a sufficient number pulled up to give more room. All flowers past their best require immediate removal from the plants. When well grown, Asters are grand autumn-blooming plants. Lines of dwarf Helichrysums are very pretty if kept in good condition by keeping all plants of a height.
Phloxes, Delphiniums, double Pyre-thrums, etc, if cut over directly the early bloom is past, as a rule bloom again the same season, though it is doubtful if they will do so this year. Antirrhinums raised from seed this past spring will now be getting to a flowering size. These are a beautiful class of plants as improved, as they now are. In order to keep the strain as fine as possible, the worst varieties ought to be destroyed as soon as they are seen to be worthless, and the best only allowed to carry seed. Sowings of these, of the beautiful varieties of Campanula calycanthema, of Sweet-Williams, Pansies, and other things requiring autumn sowing, should be made during this month. The ground should be well enriched, but made firm in order to have the young plants stubbly and hardy. Flower-gardens in box should have the edgings cut now, but not hard in. Shrubs, if not already looked over, require looking to, - at least cutting back the strongest growths, if close pruning is objected to. It is especially necessary at this season not to neglect grass-cutting amongst beds. No matter how effectively the flowers may be arranged and managed, unless the setting of grass is kept in like condition the entire good effect will be marred. The same remark applies to walk-edgings and the walks themselves.
R. P. B.