This section is from the book "How To Make A Flower Garden", by Wilhelm Miller. Also available from Amazon: The Well-Tended Perennial Garden: Planting and Pruning Techniques.
Watering is an exacting labor, and yet half of it is usually unnecessary. The reasons why it is unnecessary are two: the soil is so shallowly prepared that the roots do not strike deep enough; we waste the moisture by allowing the soil to become hard, thereby setting up capillary connection with the atmosphere and letting the water escape. See how moist the soil is in spring. Mulch it so that the moisture will not evaporate. Mulch it with a garden rake by keeping the soil loose and dry on top. This loose, dry soil is the mulch. There will be moisture underneath. Save water rather than add it. Then when you do have to water the plants, go at it as if you meant it. Do not dribble and piddle. Wet the soil clear through. Wet it at dusk or in cloudy weather. Before the hot sun strikes it, renew your mulch, or supply a mulch of fine litter. As many plants are spoiled by sprinkling as by drought. Bear in mind that watering is only a special practice; the general practice is so to fit and maintain the ground that the plants will not need watering.
The less your space the fewer the kinds you should plant. Have enough of each kind to be worth the while and the effort. It is as much trouble to raise one plant as a dozen.
It is usually best not to try to make formal "designs" with annuals. Such designs are special things, anyway, and should be used sparingly, and be made only by persons who are skilled in such work. A poor or unsuccessful design is the sorriest failure that a garden can have. Grow the plants for them-selves - pinks because they are pinks, alyssum because it is alyssum, not because they may form a part of some impossible harp or angel.
This brings up a discussion of the proper place to put the annuals. Do not put them in the lawn: you want grass there, and grass and annuals do not thrive well together. Supposing that you grow the annuals for garden effect, there are two ways of disposing them - to grow in beds or in borders. Sometimes one method is better and sometimes the other. The border method is the more informal, and therefore the simpler and easier, and its pictorial effect is usually greater, but in some places there are no boundary lines that can be used for borders. Then beds may be used; but make the beds so large and fill them so full that they will not appear to be mere play-patches. Long beds are usually best. Four or five feet wide is about the limit of ease in working in them. The more elaborate the shape of the bed, the more time you will consume in keeping the geometry straight and the less on having fun with the plants. Long points that run offinto the grass - as the points of a star - are particularly worrisome, for the grass-roots lock hands underneath and grab the food and moisture. A rectangular shape is best if you are intent only on growing flowers.
Of course, if your heart is set on having a star on the lawn, you should have it; but you would better fill it with coloured gravel.
It is surprising how many things one can grow in an old fence. The four-o'clocks shown on page 17 illustrate this point. Most persons owning this place would think that they had no room for flowers; yet there the four-o'clocks are, and they take up no room. Not all annuals will thrive under such conditions of partial neglect. The large-seeded, quick-germinating, rapid-growing kinds will do best. Sunflower, sweet pea, morning-glory, Japanese hop, zinnia, big mangold and amaranths are some of the kinds that may be expected to hold their own. If the effort is made to grow plants in such places, it is important to give them all the advantage possible early in the season, so that they will get well ahead of grass and weeds. Spade up the ground all you can. Add a little quick-acting fertiliser. It is best to start the plants in pots or small boxes, so that they will be in advance of the weeds when they are set out.
First and last, I have grown practically every annual offered in the American trade. It is surprising how few of the uncommon or little-known sorts really have great merit for general purposes. There is nothing yet to take the place of the oldtime groups, such as amaranths, zinnias, calendulas, daturas, balsams, annual pinks, candytufts, bachelor's-buttons, wallflowers, gilias, larkspurs, petunias, gaillardias, snapdragons, cockscombs, lobelias, coreopsis or calliopsis, California poppies, four-o'clocks, sweet sultans, phloxes, mignonettes, scabiosas, dwarf nasturtiums, marigolds, China asters, salpiglossis, nicotianas, pansies, portulacas, castor beans, poppies, sunflowers, verbenas, stocks, alyssums, and such good old running plants as scarlet runners, sweet peas, convolvuluses, ipomeas, nasturtiums, balloon vines and cobeas. Of the annual vines of recent introduction, the Japanese hop has at once taken a prominent place for the covering of fences and arbors, although it has no floral beauty to recommend it.
The California poppy - Eschscholuia Californica.
For bold mass-displays of colour in the rear of the grounds or along the borders, some of the coarser species are desirable. My own favourites for such use are sunflower, castor bean, and striped Japanese corn for the back rows; zinnias for bright effects in the scarlets and lilacs; African marigolds for brilliant yellows; nicotianas for whites. Unfortunately, we have no robust-growing annuals with good blues. Some of the larkspurs are perhaps the nearest approach to it.
For lower-growing and less gross mass-displays the following are good: California poppies for oranges and yellows; sweet sultans for purples, whites and pale yellows; petunias for purples, violets and whites; larkspurs for b'ues and violets; bachelor's-buttons (or cornflowers) for blues; calliopsis and coreopsis and calendulas for yellows; gaillardias for red-yellows; China asters for many colors except yellow.
Horned poppy (Glaucium luleum). Sometimes grown as an annual.
For still less robustness, good mass-displays can be made with the following: Alyssums and candytufts for whites; phloxes for whites and various pinks and reds; lobelias and browallias for blues; pinks for whites and various shades of pink; stocks for whites and reds and dull blues; wallflowers for brown-yellows; verbenas for many colours.
Some of the common annuals do not lend themselves well to mass-displays. They are of interest because of peculiar foliage, odd or unusual flowers, special uses, and the like. Of such are portulacas (for hot, sunny places), balsams, cockscombs, poppies (the blooming period is short), pansies, dwarf convolvuluses and dwarf nasturtiums, snapdragons, amaranths, four-o'clocks, mignonettes, alonsoas, schizanthus, nolanas, argemone, horned poppy, and many others.
I should never consider a garden of pleasant annual flowers to be complete that did not contain some of the "everlastings," or immortelles. These "paper flowers" are always interesting to children. I do not care for them for the making of "dry bouquets," but for their interest as a part of a garden. The colours are bright, the blooms hold long on the plant, and most of the kinds are very easy to grow. My favourite groups are the different kinds of xeranthemums and helichrysums. The gom-phrenas, with clover-like heads (sometimes known as bachelor's-buttons), are good old favourites. Rhodanthes and ammobiums are also good.
Among the ornamental annual grasses, I have had most satisfaction with the brizas, coix or Job's tears, and some of the species of agrostis and eragrostis.
Some of the perennials and biennials can be treated as annuals if they are started very early indoors. A number of the very late-flowering annuals should also be started indoors for best success in the northern States, as, for example, the moonflowers and the tall-growing kinds of cosmos.
If flowers of any annual are wanted extra early, the seeds should be started indoors. It is not necessary to have a greenhouse for this purpose, although best results are to be expected with such a building. The seeds may be sown in boxes, and these boxes then placed in a sheltered position on the warm side of a building. At night they can be covered with boards or matting. In very cold "spells" the boxes should be brought inside. In this simple way seeds may often be started one to three weeks ahead of the time when they can be sown in the open garden. Moreover, the plants are likely to receive better care in these boxes, and therefore to grow more rapidly. Of course, if still earlier results are desired, the seeds should be sown in the kitchen, hotbed, coldframe, or in a greenhouse if accessible.
In starting plants ahead of the season, be careful not to use too deep boxes. The gardener's "flat" may be taken as a suggestion. Three inches of earth is sufficient, and in some cases (as when the plants are started late) half this depth is enough.
Of late years there has been a strong movement to introduce the hardy perennials into general cultivation. This is certainly to be encouraged everywhere, since it adds a feeling of permanency and purpose-fulness that is needed in American gardens. Yet I should be sorry if this movement were to obscure the importance of the annuals. We need this colour and variety.
Mexican poppy - Argemone Mexicina.