Watering and Feeding Perennials
How often you water perennials depends on the usual factors: climate, soil type, sun and shade exposure, and so on. Most perennials require water only when the top few inches of soil dry out but before the plants start to show symptoms of drought stress. Perennials from arid habitats generally benefit from a longer dry interval between waterings. Plants from wet places prefer never to dry out completely.
Following are a few other special guidelines for perennials to keep in mind:
- In regions with cold winters, start lengthening the intervals between waterings in late summer to toughen (harden off) your plants for winter. You don't want perennials to face the first frost with new growth that's easily damaged.
- Mediterranean flowers and others from similar, dry summer climates often require a summer dormancy period. Keep the soil fairly dry during this "naptime." During summer, deep-soak infrequently — only when the soil is completely dry.
- Where winters are cold and dry, plan on watering perennials once a month if it doesn't rain or snow for a few weeks. Water when temperatures are above freezing and the soil surface thaws out.
Fertilizing perennials is simple. One application of a complete fertilizer to your perennial bed in early spring should be enough. If you think that plants are lagging (weak or pale growth), follow up with another shot or two of the same fertilizer during the growing season.