Other perennials are continually being developed by amateur botanists and gardeners. As a result of this cultivation and inbreeding, perennials as a rule are not as hardy as other varieties. Another disadvantage is tendency of certain perennials to die down after flowering, thereby leaving gaps in garden.

There are a number of ways to solve problems of short-flowering periods and resultant unsightly spaces. One way is to intersperse perennials with annuals and other bulbs and flowering plants whose bloom occurs either later or earlier than that of perennials. Some perennials are easy to transplant: chrysanthemums, for example, can be moved from one place to another with no noticeable effect on their vigor.

This is another way to keep color and bloom throughout growing season. A garden of perennials, either by themselves or mixed with annuals and other bulbs, should be placed along a path, or as a border, with a background of trees, shrubs, a wall or fence.

The background shows brilliant coloring to best advantage. Some varieties can flourish in shade, such as anemone, lily of valley, day lilies, sweet pea, primrose, hollyhock, harebell and peonies, but these flowers must be chosen carefully and faced so that some sun reaches them every day.

The big disadvantage of outdoor sowing is that one sacrifices control over circumstances under which seeds will germinate. In an indoor hotbed, or coldframe, conditions of moisture, heat, etc., can be regulated. Not so in outdoors, where dryness or changing weather can destroy weaker seeds quickly. If an outdoor seedbed is planned, choose a spot with good soil.

Then work in a portion of your compost pile, pulverizing soil to depth of 3 inches. Adding some sand and peat moss increases effectiveness of bed. Most seed may be planted on surface, and deepest one should plant is 1/2 inch. The bed should be well-watered after seed has been broadcast over entire area. The bed can then be lightly tamped.