|What to plant in a shady acidic soil? Zone 4.|
|Impatiens (Impatiens wallerana) are the kings of shade-loving annuals and are readily available at almost every garden center. Their brightly colored flowers are available in every color except true blue, black, brown, or gold. Flowers are available in single or double (rose-like) forms. Their low growing (8 24 inches tall), spreading habit make them ideal beneath trees, in containers, or near buildings.
The large blossoms (3 inches in diameter) of New Guinea impatiens (Impatiens x hawkeri) make them a shade garden favorite. The variety of flower colors equals that of typical impatiens. But, New Guinea impatiens have patterned or variegated leaves that complement the brightly colored flowers. Heights range from 9 inches to 3 feet tall and plants perform beautifully in the garden or in containers.
Rose balsam (Impatiens balsamina) is another type of impatiens that was popular 50 years ago. They are taller (1 2 feet) than the other impatiens and they prefer a couple of hours of sunlight for best bloom. Flowers are often double, resemble small roses when fully open, and are produced at the tips and leaf axils along the tops of the stems. The fruit or seed capsules are also interesting. As the capsules ripen, they are sensitive to touch or movement. Once touched, they explode, sending seed great distances.
Wax begonia (Begonia x semperflorens) is another common shade-loving annual. The succulent leaves are dark green or bronze, depending on cultivar. The thick flowers are white, pink, red, or salmon and bloom all summer. Plant height ranges from 6 to 12 inches, depending on cultivar and growing conditions. Wax begonias are extremely durable and make excellent bedding or container plants in shady or sunny sites.
For vibrant foliage in a shady site, Coleus (Solenostemon hybrids) is king. Combinations of burgundy, purple, red, pink, orange, yellow, gold, white, and green are all available in different cultivars of coleus. Flowers are lavender or white, insignificant, and often removed so as not to distract from the interesting foliage patterns and colors. Coleus are also easy to root from cuttings, and rooted plants can be overwintered indoors.
Browallia or silver bells (Browallia speciosa) is a lesser known annual for shady sites. The light blue or white flowers grace the tops of 6 12 inches tall plants for most of the summer. Plants are commonly grown in containers or hanging baskets for shady decks or patios.
Wishbone flower (Torenia fournieri) is another uncommon annual for shade gardens. The white, pink, purple, yellow, or blue flowers are tubular and resemble snapdragons from a distance. Many of the cultivars have contrasting or dark spots on the petals. The stamens are fused and resemble a wishbone, hence the common name. Plants are 6 12 inches tall with bright green leaves.
Another annual noted for attractive foliage instead of flowers is polka dot plant (Hypoestes phyllostachya). The leaves are speckled with red, pink, or white dots, giving the plant its common name. Plant height ranges from 9 to 18 inches tall. Polka dot plant performs best in containers and garden beds in partial shade.
Caladium (Caladium bicolor) is a tender bulb that is often treated like an annual. The bright red, pink, white, and green leaves are the showy feature of this shade-loving plant. Each two-toned leaf is heart or arrow-shaped and displays prominently all summer. Plants are 2 3 inches tall depending on cultivar. Flowers are insignificant and rarely produced. Tubers or roots should be dug in fall and stored indoors over the winter.
Another tender bulb that is often treated like an annual is tuberous begonia (Begonia x tuberhybrida). The stunning rose or camellia-like flowers are available in pink, red, orange, lavender, yellow, or white. Leaves are thick, heart-shaped, and sometimes variegated. Plants are commonly grown in containers or hanging baskets. Just like caladium, the tubers should be dug in fall and stored indoors over the winter.
These are just a few of the many shade-loving annuals that can brighten the summer landscape. A few other annuals that tolerate shade or partial shade are: nasturtium (Tropaeolum), flowering tobacco(Nicotiana), pansy (Viola), lobelia (Lobelia), bachelor button (Centaurea), Pinks (Dianthus), bells of Ireland (Moluccella), forget-me-not (Myosotis), baby blue eyes (Nemophila), perilla (Perilla), fuchsia (Fucshia), and elephant ear (Colocasia).