Garden flowers provide showy, colorful displays in a xeriscape garden. Xeriscape (zer-i-skap) is a water-conserving landscape. Annuals and perennials can be integrated with shrub borders and groups of trees, or they may be planted in their own beds along fences, walls, walks, and patios.
Before selecting garden flowers, check your soil. Most flowers do poorly in heavy clay, due to lack of oxygen to their roots. Sandy soils may have poor water-holding capacity and be low in available minerals. If either extreme is true in your yard, do not plant perennial flowers the first year or two.
Improve the soil with sphagnum peat or compost, available in bales or bags at garden centers. Incorporate 1 cubic foot of sphagnum or compost per 8- by 10-foot area to a depth of 9 inches. Plant only annuals so it will be easier to cultivate and incorporate additional organic matter in the fall, after the plants are killed by frost. Add more sphagnum or compost each year until the soil is easily worked and does not compact. Perennial flowers may then be planted.
Select plants that are compatible with the exposure. For north sides of structures or among shrubs, choose plants that tolerate less sun. For example, perennials for a shaded spot might include canterbury bells, primrose and violets. Such plants usually need cool, more consistently moist soils than most garden flowers. They can, nevertheless, be useful in the shaded parts of a xeriscape. Add organic mulches such as wood chips to reduce watering frequency.
Most bulbs do best in full sun, but they must have well-drained soils. Spring-flowering bulbs are well-suited for xeriscape plantings because they are drought-evaders. That is, they grow in the cooler, more moist spring and fall seasons and lie dormant underground during the hot summer months.
Use tulips, grape hyacinths, hyacinths, daffodils, and crocus for naturalizing a xeriscape. In fall, plant spring-blooming bulbs in the areas you want them.
Almost all annuals commonly sold do well in xeriscape gardens with some soil preparation and no more than one good watering a week (1 to 2 inches). For hot, dry exposures, the most reliable include marigolds, zinnias, cockscomb, sweet alyssum, and bachelor’s button. Where soils are shaded and cooler, use annuals such as lobelia, pansy, and forget-me-not.