This situation encourages root diseases and overwatering symptoms such as yellow leaves. Water annuals about as often as turf. Refer to the individual plant descriptions to see which plants like more or less moisture than average. When annuals need less water than the surrounding turf, using raised flower beds will improve drainage and reduce the chance of overwatering. Foliage should be kept dry if at all possible during watering.
Soaker hoses work best.
Many annuals, chiefly begonias, impatiens, coleus, alyssum, ageratum, lobelia, vinca, salvia and others, require little additional care. Their flowers fall cleanly from the plant after fading and do not need to be manually removed. Others, such as marigolds, geraniums, zinnias, calendula and dahlias will need to have faded flowers removed. Deadheading can be done with pruning shears or sometimes with the fingers. A few annuals, primarily petunias, snapdragons and pansies, may need to be pinched back after planting or after the first flush of bloom to keep them compact and freely flowering.