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.
There is one feature of present-day flower-gardening which we are not so thankful for as we ought to be, and that is, that there is no necessity for any one to attempt to follow the style of his neighbour, as he was obliged to do a dozen or twenty years ago, at the risk of being set down as altogether behind the times if he failed to do so. Nowadays, any one who has a liking for strong colours can satiate his appetite for these; or, if bedding in greys and greens is his penchant, he can satisfy his mental liking for these. He can go in for beds of Cannas, Castor-oil plants, Wigandias, and other sub-tropical subjects; or he may more cheaply get fine-foliage effect by planting Rhubarb and Globe Artichokes. He may pin his gardening creed to Daffodils and "fair Lilies," or he may broaden the borders of his likings by taking in one and all of these; and even then he may with some advantage add to the number of his styles of flower-gardening by adding the very easiest of flowers to cultivate - Annuals - without in any degree violating public taste.
Now and again we come across a bed or two of common hardy Annuals in conjunction with other flowering plants; and some of them have long been admitted and recognised as standard bedding-plants; but the list may be largely increased, even at the present day, when so many fresh flowers have been added to our gardens. There are instances where bedding is entirely carried out with Annuals; but these cases are of limited number and not generally known, though those who have seen such gardens at the height of their beauty agree in estimating their effect as bedders. But setting aside the suitability of many Annuals for effect in masses, a selection of good sorts should be a feature in every well-stored garden. Their cultivation is of the simplest. Half-hardy Annuals, also, are amenable to a much simpler mode of cultivation than is commonly practised. The following list of hardy and half-hardy Annuals, all of which may be sown any time during the first half of the present month, is made up of sorts which are certain to please when properly managed.
The under-named form the selection of hardy Annuals : Double Dwarf Scabious, Collinsia bicolor, Clarkia integripetala limbata, Clintonia elegans, Convolvulus minor (dark-purple var.), Delphinium cardio-petulum, Gilia tricolor, Godetia, Lady Albemarle, Leptosiphon roseus, Limnanthus Douglasi, Linum grandiflorum rubrum, Love-lies-bleeding, Dwarf Blue Lupine, Mignonette, Nasturtium Ruby King, Nemophila insignis, Double White Pyrethrum, Saponaria calabrica and white variety, Blue Stonecrop, Venus's Looking-glass, Oxalis tropasoloides, Sweet Peas, and Viscaria cardinalis. If the following conditions are followed out, these will not cease flowering until the approach of winter stops them. They require, as a primary necessity, a deeply-worked and rich soil: though Annuals are short-lived, they require high living for that short period to secure continued success till the last. Thin sowing is another item of importance, with small seeds especially - the percentage of seeds sown over what is necessary is something enormous. Next to a rich soil, room for the plants to grow is of most importance; and if a swarm of seedlings are allowed to fight out amongst themselves the battle of the fittest, all preparation of the soil will have been thrown away.
This applies to all the plants named - Sweet Peas with the rest. Mignonette is a common instance of the evil effects of thick sowing. In such circumstances wiry, little, single-stemmed plants are produced, which flower and ripen their tiny crop of seed as if they were in a hurry to get the business done, and then the Mignonette-bed is a blank, or worse than a blank, for the remainder of the season. But in rich soil and a thinly-seeded bed, plants 18 inches to 2 feet through will be produced before they have stopped growing, and very little urgency shown as to the production of a crop or seed. This tendency of Annuals to run to seed makes it a necessity, in dry seasons more especially, to go over the plants and gather off all seed-pods at least once in the season. This is not such a formidable undertaking as it may appear, and it adds in a very material degree to the continued prolificness of the plants.
Of half-hardy Annuals, which do better in our northern climate raised in frames than by any other means, the following sorts are all well worth growing as decorative plants : Dwarf Chrysanthemum Asters, Dwarf Helichrysums, African Marigolds, Phlox Drummondi atro-coccinea, Dwarf Mimulus, Dianthus Heddewigi and double Indian Pinks, common Sunflowers. Antirrhinums and OEnothera Lamarck-iana may be treated in the same manner with the others. These, like the hardy Annuals named, will, under good cultivation, keep on flowering as late in the year as ordinary bedding-plants. The way I treat them is to set apart a sufficient number of frame lights; to prepare the bed of Mushroom-dung and light soil in equal proportions; to sow the seeds very thinly over the entire surface of the beds, covering slightly with some fine soil, which is patted down gently with the back of a spade. Then the sashes are put on, and the whole covered with mats until the seedlings appear. The mats keep everything underneath them in quite equable conditions, and save all bother. As the seedlings progress and the weather gets warmer, more and more ventilation will be required, until the sashes are removed altogether.
If sown during the first half of this month, in the end of May they will be ready for removal into their flowering places. Choose a dull day. Make a mixture of soil and water, and dip the roots of the plants in this, a handful of plants at a time, and plant them with a common dibber, giving each plenty of room to grow. If the weather breaks out strong the next day or two succeeding the one on which the plants are set out, they may require watering. I find in the hottest weather that one watering is sufficient, only it is better to hoe the ground the next morning. In moderately sunny weather, the plants take care of themselves without being watered. R. P. Brotherston.