Homeowners fall into two categories: those for whom gardening is a chore and want to do little or no work in the garden, and those who love gardening and enjoy puttering, and the maintenance necessary to keep a vibrant looking palette of plant material. Perennials offer color in the garden, year after year, but require deadheading when the flowers fade.
Annuals are colorful for a season and need to be replaced. Flowering shrubs usually bloom once a year for several weeks, the flowers fade, but the plant foliage remains.
Many perennials require deadheading spent blooms two or three times a year. For example, lavender may bloom in April and the flowers will be vibrant thru May. When they fade, the flowers should be deadheaded and then fertilized. The plant will then flower again in June. Then in late July or early August, deadhead spent blooms and fertilize and maybe a third flush of bloom will appear in September. Then after the winter the plant will repeat the cycle the following year. If this deadheading of spent blooms is not done, the plant will become leggy and scraggly.
Other perennials such as salvia will bloom contiguously throughout a growing season and be ready for deadheading in late fall or early winter, and bloom again the following year.
Still other perennials require waiting to deadhead until the danger of frost has passed. Cutting encourages new growth, which is tender and could freeze if left unprotected. The old spent blooms and scraggly foliage serve as a blanket to keep the frost off of the new baby growth. This new growth is next year’s plant, and the old stalks and foliage can be removed in March or April.
Following are a list of our favorite perennials:
Lavender provence (French lavender) – a 3-4 high and wide plant with soft fragrant flowers throughout the spring and summer. Many other varieties are available, such as Lavender stoechas quastii (Spanish lavender), and Hidcote, which is a dwarf variety of English lavender.
Salvia greggi i (sage) – 3-4 high and wide, full sun grower, comes in deep red, salmon, purple and white flowers. Needs to be cut back in winter, even though it is semi evergreen.
Salvia leucantha (Mexican sage) – larger sprawling salvia featuring purple and white flowers on a five foot by five foot plant. Wait until mid March to cut back all the dead branches and flowers. You will see the new growth emerging from the base.
Stachys byzantine (Lambs Ears) – soft gray foliage, full sun, to 18″ tall
Helleborus orientalis – partial to full shade plant to 18′ tall. Available colors are rose, burgundy, ivory and dark blue
Hostas – there are many many hosts – all want partial to full shade and moist soil. Snails love them, so be sure to use slug and snail bait!
If a homeowner is willing to do the work required, gardening with perennials is fun and adds beauty and reliable color to the garden. If they don’t have the time or inclination to deadhead as needed, the plant will not be attractive and they should not choose perennials.