Watering Annual Flowers
Because annuals lack the extensive root systems that most perennials and hardy bulbs have, it’s important to pay attention to their watering needs. Most annuals need about an inch of water each week from rain and/or by watering. If annuals are allowed to dry out to the point of visible wilting this stress will take its toll on their health. Their blossoms will be dull and small, and they will not last as long as annuals that have been properly watered.
Watering Perennial Flowers
Perennials are generally deeper rooted and more drought tolerant than annuals, but they are vulnerable to both over-watering and under-watering. Generally, they need ½ to 1 inch of water a week either by watering or from rainfall. To keep perennials happy when you do water, be sure to moisten the soil to a depth of 1 foot or so. With plants that are subject to diseases such as crown rot, only water when the soil is dry.
Hardy bulbs need no more water than most other plants in your ornamental garden. The only critical period is the few weeks following the bloom period, if rainfall has not been adequate. For water requirements of summer-flowering bulbs, see the individual plant files in Yardener’s Helper.