How to Choose Annuals and Biennials

Annuals and biennials are short-lived but valuable plants in the garden. They are often called bedding plants because they are used in beds for one season and then discarded. An annual is a plant whose entire life cycle, from germination to seed production to death, takes place within one year. Choosing annuals and biennials requires a little planning but the landscaping rewards are great.

Things You'll Need

• Plant seeds

Instructions

1. Learn the difference between hardy annuals and half-hardy annuals. Those that are able to withstand frost are known as hardy annuals. Half-hardy annuals have to be raised under glass and are planted out only after all risk of frost is over. Many of the most popular plants used as annuals come originally from the tropics.

2. Select hardy annuals. Hardy annuals include forget-me-nots (Myosotis sylvatica), pot marigolds (Calendula officinalis), cornflowers (Centaurea cyanus), candy tuft (Iberis umbellata), wallflowers (Cheiranthus), which provide cheerful color and scent in spring, sweet peas (Lathyrus odoratus) and the majestic sunflower (Helianthus annuus).

3. Select half-hardy annuals. Half-hardy annuals include Begonia semperflorens, a perennial from Brazil grown as an annual with clusters of flowers during the summer, petunias, lobelias, Convolvulus tricolor and Cosmos bipinnatus in a range of colors from blue-purple to crimson, single flowers and feathery foliage. Dianthus chinensis is a popular annual pink with some beautiful colored forms, and Dimorphotheca sinuata has lots of daisy flowers with dark brown centers and a variety of petal colors, mainly in the orange and salmon-pink range.

4. Select biennials. A biennial plant takes two years to complete its life cycle. During the first season after sowing, it produces leaves. It then overwinters and the following year produces flowers. Examples of biennials useful in the garden are foxgloves (Digitalis) and hollyhocks (Alcea), which are in fact perennials but treated as biennials.

5. Plant annuals or biennials in beds. Many bedding plants are true annuals and die down at the end of the season. Others are perennials but are treated as annuals because they produce the best displays in just one year, or else they are not frost hardy. Pansies are hardy perennials but are treated as annuals or biennials. They are usually more effective if just one or two colors are used together rather than if all the colors are jumbled into one bed.

6. Plant annuals or biennials in containers. Half-hardy and hardy annuals are ideal as container plants. Many have a drooping habit just right for hanging baskets. Some pelargoniums are good for this. Always plant generously, getting as many plants in as possible. The rootballs of the plants can touch, provided the container is deep enough to allow a little compost beneath them.

Tips & Warnings

• Purchase a color wheel from the craft store to help you decide on color combinations.