HERBACEOUS ORNAMENTALS -PERENNIALS, ANNUALS AND BULBS

This chapter focuses on herbaceous perennials, annuals and bulbs. Each of these three groups will be presented separately. Most plants in these groups are prized for their showy blossoms. All three groups have been extensively hybridized by commercial growers to change the following characteristics:

  • flower color and size
  • foliage color, size and texture
  • hardiness
  • ability to self-clean (drop spent blooms)
  • bloom time
  • increased petal number
  • fragrance
  • disease resistance
  • drought tolerance
  • shade and sun tolerance

KEY CONCEPTS

  1. General Discussion of Perennials, Annuals and Bulbs
    1. Perennials
    2. Annuals
    3. Bulbs
    4. Biennials
    5. Garden design
  2. General Cultural Requirements of Perennials, Annuals and
  3. Perennials
  4. Annuals
  5. Bulbs

Return to Introduction

 

GENERAL DISCUSSION OF PERENNIALS, ANNUALS AND BULBS

 

PERENNIALS

Perennials have roots that live through the winter. They are able to regrow above-ground parts in spring. Although some perennials can last almost indefinitely, others may last only a few years. You should remember that perennial does not mean perpetual. However, perennials usually can be propagated asexually for additional plants.

Perennials have a shorter bloom period than annuals. Some will bloom continuously if spent flowers are removed. Others will rebloom later in the same season.

Gardeners may come upon the term "half hardy." Half hardy means "marginally hardy." In severe winters these plants will not survive. But in mild winters with ideal conditions and sufficient mulch, half-hardy plants will survive.

 

ANNUALS

Annuals complete their growth cycle in one year. To propagate themselves from year to year, annuals produce great quantities of seeds. If the flowers of annuals are cut before seeds can form, more blooms rapidly grow to assure a seed crop. Annuals usually produce more flowers than other types of flowering plants. They also flower earlier in their life cycle. Many annuals produce blooms from planting to frost.

Some annuals are perennial in warmer hardiness zones. Examples of perennials grown as annuals in Ohio are geraniums, dahlias, snapdragons, mealycup sage, pansies and Iceland poppies.

   

BULBS

This chapter has a section entitled "Bulbs." Although all plants in this section are called "bulbs," technically this is not correct. Plants in this section include true bulbs, corms, tubers and rhizomes.

All bulb-type plants have underground storage parts. Bulb-type plants can survive dormancy without nutrients or moisture. In this sense they are perennials. Some bulbs are planted once and last for years. Others last only a year or two. Nonhardy bulbs must be planted each spring, dug up in the fall and stored where they will not freeze.

   

BIENNIALS

Biennials are another group of plants that are common in the home landscape. Many gardeners are familiar with hollyhocks, Canterbury bells, most foxgloves, snow-in-summers, and money plants. Biennials produce only foliage and roots the first year. The roots survive the first winter. During the second growing season, the biennial blooms, produces seeds and then dies. Biennials may reseed and appear to be perennial.

Gardeners usually purchase biennials from nurseries, rather than grow them from seed. This avoids wasted space taken by biennials during their first, nonflowering year of growth. Biennials require the same basic type of care as annuals and perennials.

Perennials, annuals and bulbs give the home landscape color and foliage interest throughout the growing season.

The broad range of bloom time and variety of flowers and foliage can produce continuous color and interest in a well-thought-out plan. Dried flowers, fruit, seed heads and leaves may be left on plants for winter interest and as a source of food and shelter for birds.

 

GARDEN DESIGN

The most successful gardens usually begin with a carefully planned design. If you forego planning, the results are often a haphazard collection of plants. Too many variations in shape, color, size and texture create confusion. A drawing on paper is helpful for location of dormant bulbs as well as perennials.

  [illus. p. 6 Michigan's "Growing Perennials"]

Use graph paper or paper with a grid to sketch to scale the layout of your yard. Draw in all existing buildings and plants. Plant showy selections near windows, a porch or a patio where they will be seen frequently. Use shade-tolerant varieties in areas with dappled shade or part sun. Remember that tree and shrub roots compete for nutrients and moisture.

 

 

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