When strong wooden boxes have been procured, it is quite easy to tack on the cork one’s self, provided one has a sharp knife and a good supply of long nails, and it is most fascinating work; it is advisable to wear gloves during the process, as the hands may become rough otherwise. Seven pounds of the cork may be had for a shilling of any seedsman, and three lots will do two boxes of the average size. The soil should be fairly light, like that used for potting, but before the boxes are filled, several holes, bored with a red-hot poker, should be made in the bottom, and a thin layer of “crocks” spread over them; do not quite fill the box with soil, but leave an inch or two free to allow of watering, and even more if a layer of moss or cocoa-nut fibre is used to cover the surface of the soil; this is certainly an improvement till the plants get large enough to cover it themselves. Only artificial manures must be used to fertilize the roots, and even those must not be given too often, but only in the hot weather, when growth is quick, as they are stimulating to a great degree.
Constant renewals are necessary, if the boxes are to look gay all the year round; even the best gardeners acknowledge this. If continuous bloomers are chosen, however, the cost is considerably modified. Perhaps the winter shrubs are the most expensive item; yet they are often chosen without much regard to cheerfulness; indeed, the favourite kinds present a most funereal appearance.
Aspect has always a good deal to do with the selection of plants, but in the case of windows facing north and east, it is the cold winds more than the absence of sun which restricts the choice. Shelter is a great factor in their well-being.
SHOWY IN WINTER. In a cosy box with a western exposure, and protected on the north, the golden-tipped retinosporas make a pretty show during the cold months of the year, and form a welcome change from the prevailing dark green tones. Cotoneasters, pernettyas, and the variegated euonymus are also very suitable. The polypody ferns, being evergreen, look very well too, and will thrive facing all four points of the compass. In the spring, dwarf wall-flowers, interspersed with different kinds of bulbs, make the boxes look bright, and the new pyrus maulei is also very pretty at this season. The perennial candytuft, too, is a splendid flower for late spring, particularly iberis correafolia, which has a neat habit, and bears quantities of snow-white flowers; it likes sun, and not too much moisture. The yellow jasmine, which is so pretty in winter, looks extremely well when allowed to droop over the edges of a box, as it flowers in quite a young state. The mossy saxifrages are suitable for the edges of the box, and are always ornamental; their charming white flowers, supported on red stalks, appear about May.
Such bulbs as the Duc Van Thol tulips are very bright, and mix well with the shrubs; they should be put in some time in October. Crocuses look well, too, but should not be placed in the same box as the tulips, or too gaudy an appearance will result. A thick planting along the front of the box of the Starch hyacinth—muscari—is uncommon, and an exceedingly nice thing to have, as the moment the window is open fragrant whiffs, resembling new-mown hay, pour into the room, especially on a sunny morning. When these bulbs have to make way for the summer flowers, it is advisable to plant them out in the garden and use another lot next year, as the constant transplantation somewhat weakens them. Of course, one could leave them in the box during the summer, if it were not for the unsightly decaying leaves, which must on no account be cut off.
About the middle of May for the South of England, and a fortnight later for the North, is the time to furnish the boxes for the summer. If the window is small, low-growing plants and trailers should prevail.
FOR COLD ASPECTS. Some good flowers for north and east aspects are fuschias, calceolarias, begonias, and the lovely white campanula isophylla; the latter thrives best in such conditions, bearing finer flowers for a much greater length of time than where the sun scorches it. These plants accord well with stucco, which serves to show up their whiteness more than anything. Marguerites, yellow and white, also thrive in the cooler windows of a house, and are not so exigent in the matter of watering when so placed. When selecting begonias for boxes it is well to choose the single varieties with moderate-sized blossoms; the big flabby ones soon become spoilt by rain, and are not produced so freely, nor is their habit of growth so good.
For hot situations the double geraniums are splendid, but they should not be mixed with lobelias, as they look infinitely better when grouped by themselves, the shades ranging from dark crimson to the palest salmon-pink.
PRETTY TRAILERS. The quick-growing tradescantia with its many-jointed stems and glossy bright green leaves, softens the somewhat formal appearance of the geraniums, and will cover all the bare soil in a marvellously short space of time, and droop over the edges in long streamers; it is quite distinct from the tall tradescantias mentioned in a former chapter, and is the easiest thing in the world to propagate, as any little bits saved over from a bouquet will make roots in a bowl of water, or they can be “struck” in the ordinary way in a pot under glass. The variegated tradescantia is a very choice trailer, but a little more tender than the other, and requires a sunny position, while the plain green variety will do anywhere outside in the summer, even growing well under trees.
For autumn there are the hardy chrysanthemums, and if dwarf varieties with fibrous roots are chosen, a very good show can be made with these till the middle or end of November. The protection afforded them by the house keeps them in good condition longer than when they are in the open, especially when a thin veiling, such as tiffany, is afforded them on cold nights. Even newspapers will keep out several degrees of frost, and form a very cheap method of protection.