No components of the landscape require more maintenance time than flower plantings. This is why landscapes with a low budget for maintenance must minimize the use of flowers. Reasons for the high maintenance costs are that
• weeds must be pulled by hand or controlled with costly selective herbicides
• flowers are more susceptible to insects and diseases that mar their aesthetic appearance, therefore requiring additional expenditures for pesticides
• flowers tend to go to seed or get leggy with age if not pinched back frequently during the growing season (this subject is discussed later in the chapter)
• many perennials bloom only once a year but must be cared for throughout the growing season to ensure a good flower display the following year
• some perennials, notably the tender bulbs, must be dug up, put into storage for the winter, and set out again each spring
Several good herbicides are approved for use in flower plantings. If applied for preemergence and postemergence control, a weed-free flower planting can be attained. One danger of herbicides in flower beds is that the chemicals are always selective; that is they kill grasses
or broadleaved weeds, but seldom both. Since flower plantings can have characteristics of both, damage can be done to some flowers even when others are uninjured.
Most herbicides used in flower plantings lose their effectiveness if the soil is disturbed after application. In such cases, landscapers must avoid cultivating the soil surface if they wish the full benefit of the herbicide.
All flowers should be watered frequently and deeply during dry periods. Their shallow roots quickly react to drought conditions and they reach a critical wilting point much sooner than the woody plants of the landscape. Flowers planted beneath trees and shrubs must compete with the woody plants for surface water, and they will dry out faster than flowers not in such competitive locations.