Although annuals make a splendid display on their own in an annual garden, they also combine effectively with other plants. Any dull spot can be brightened almost immediately with the addition of a few colorful annuals.
If, when you look at your garden, something is lacking, see if you can identify areas that a splash of color would improve. For example, although shrub borders are flower-filled in spring and early summer, they often provide only a few blooms the rest of the season.
In many gardens, shrub plantings provide no summer color at all. It's amazing how much more attractive such an area becomes when just a few groupings of annuals are inserted. It's not necessary to plant a large bed in front of the entire length of the shrub border. Several strategically located accent clumps are usually all that is needed.
Annuals can also provide the perfect midsummer boost a perennial border may need. Plant them in the spaces where spring bulbs and some perennials are dying back, or where early flowering biennials such as foxgloves and English daisies have been removed -- anyplace an empty spot occurs.
If a perennial bed is so packed that there is no free space in which to plant annuals, consider another approach: Place pots or boxes of annuals on small outdoor tables or stools. Tuck these display stands here and there in the border. Or, if there is a fence or wall behind the border, use it as a support from which to hang half-baskets or window boxes full of flowering annuals.
Another good place to add annuals is in the vegetable patch. Not only will they enliven an area not normally expected to be colorful, they'll also provide an excellent source of cut flowers to bring indoors. Because the vegetable garden is not usually a display area, every flower can be picked if desired.
Plantings combining annuals with vegetables can be laid out in various ways. One approach would be to plant annuals around the outer edges of the garden, hiding or disguising the vegetable patch. Another alternative would be to plant rows of annuals here and there among the vegetables. Finally, a handsome combination design, especially where the total garden space is limited, would be a very formal geometric garden, laid out with some of the beds planted with annuals and others with vegetables. The final choice, of course, depends on your personal preferences as well as on the dictates of your garden site.