What time could be better than the depths of winter to dream about plants that will brighten up your garden -- right now or later this year? Today we focus on annuals and biennials that thrive in the shady areas of your landscape.

These plants are icing on the cake, adding punch to the backdrop of trees, shrubs and vines that completes your garden canvas. They also make great options for containers or window boxes on shady decks or balconies.

Annuals, obviously, are meant to be planted on a yearly basis, thereby giving us an opportunity to experiment with a variety of colors, shapes and sizes without making a long-term commitment. Many can be grown from seed or purchased as seedlings in six-packs or as larger plants in 4-inch pots. They are inexpensive when compared to the investment required for perennials in gallon- or larger-size pots.

Today's recommendations include just a few of the varieties that thrive in a Northern California shade garden.

Annuals for winter

Cyclamen: Although technically a perennial, many people grow cyclamen as an annual, since it offers nonstop winter color and can be grown indoors as well as in shady outdoor locations. The flowers range in color from fire-engine red to glow-in-the-dark fuchsia, as well pale pink, purple, white and orange. Some have dainty, fringed flowers, while others sport blooms more than 3 inches long. Leaves can be solid green or a variegated pattern.

Primrose: This annual blooms from late winter through midspring, offering a wide range of colors as well as a nice, delicate fragrance. Blooms can be solid or bicolor in shades of red, pink, yellow, purple, orange, white or blue. They generally reach a maximum height of about 8 inches. In ideal conditions, many varieties can be grown as perennials.

Annuals for spring

Tuberous Begonias: These popular plants are loaded with large, dramatic blooms that range in color from white and pink to peach and red. Their beautiful foliage can be bronze, red or deep green. They continue blooming all summer long and, in our climate, can last for several years.

Coleus: This plant, which comes in a range of sizes, shapes and colors, is grown mainly for its gorgeous leaves, which are available in shades of vivid scarlet, chartreuse or purple. Some are dramatically edged with green and brown, red and yellow, orange and gold or many other striking combinations. Though considered an annual, coleus can grow for several years in a location with ideal conditions.

Impatiens: They come in virtually every color of the rainbow, with single and double flowering forms. Most reach 8 to 24 inches in height. New Guinea impatiens grow a bit taller, and they have unusual variegated leaves.

Biennials for spring

Biennials complete their life cycle in two growing seasons. The first year they produce roots, stems and leaves. The second year, they produce their worth-the-wait flowers! When for sale at local nurseries, they are often in their second year and ready to bloom.

Foxglove: This charmer produces upright spikes of bell-shaped flowers that are great for cutting. Colors are shades of pink, purple and white. Some varieties will grow to 6 feet in height, though most are usually 2 to 3 feet tall. They prefer well-drained soil and often self-seed in the garden.

HOLLYHOCK: This upright bloomer is frequently used in arrangements, and it attracts butterflies too.
HOLLYHOCK: This upright bloomer is frequently used in arrangements, and it attracts butterflies too. (Rebecca Jepsen/Contributed)

Hollyhock: This upright bloomer -- whose flowers can be yellow, red, apricot, purple, white or even nearly black -- is frequently used in arrangements, and it attracts butterflies, too. Some varieties can reach 8 feet or more in height and up to 3 feet in width, so leave plenty of room when planting. They do best with morning sun, rather than full shade.

Sweet William: A fragrant, clover-scented plant, Sweet William is related to garden carnations. It produces small clusters of purple, white, pink or red flowers. Dwarf varieties grow to about 6 inches; tall varieties can reach 12 inches or more. They are great for cutting and for use in flower arrangements.

Rebecca Jepsen is a Santa Clara County Master Gardener. The Master Gardener program is a UC Cooperative Extension volunteer organization that supplies research-based information to home gardeners. Have a question? Call the UC Cooperative Extension Master Gardener hotline in San Jose at 408-282-3105 from 9:30 a.m. to 12:30 p.m. Mondays through Fridays; or go to www.mastergardeners.org.