If edging plants are important on the lawn they are doubly so in the garden, where we wish every foot of ground to do its best. The most famous edging plant for gardens and formal flower beds is box, and rightly so, because it is evergreen and breathes "the fragrance of eternity." (See Chapter XV.)
But in this case the purpose of the edging plant is not to furnish a transition, for the edging is often taller than the flowers within. The real purpose of box is to outline the design. For, in a formal garden the main thing is the design, while in the naturalistic garden it is the flowers. Now, design can be more pleasantly impressed by means of cool lines of evergreen foliage than by broad gravel walks, which are hot and tiresome in the sun. Thus box has been used for edging from classical times, and as it usually lives longer than anything else in a garden, some people maintain that it is impossible to have a charming formal garden without it.
In olden times the common, or tree, box was used for edging, but in the life of every garden comes a period of neglect and then the tree box overruns the walks and flower beds, thus obscuring the original design. Dwarf box is therefore better for edging flower beds, but it involves a long wait. Little plants only six inches high may cost one hundred dollars a thousand and look painfully small for several years. Box edgings need to be trimmed to a line once a year in May. They are said to be ruined sometimes by neighbouring plants overhanging them and by salt thrown upon the walks to kill weeds. They rob the flowers of plant food and are supposed to poison the ground for certain kinds. It is necessary to grow an extra supply in a reserve garden to fill gaps. There are many other drawbacks to the use of box. Before deciding to use it, every one should inquire in the neighbourhood about its hardiness and what kind and degree of shade, if any, seems best.