Unusual Flowering Annuals for Distinctive Gardens and Planters
These will make your garden stand out!
Annuals represent a wonderful, commitment-free way to experiment with color, height and texture in the garden and containers. If you're ready to move past the usual impatiens, wax begonias and petunias, consider these unusual and dramatic alternatives:
A Pair of Surprising Salvias
When most people hear “annual salvia,” they likely think of Salvia splendens, the most popular type, or of Salvia farinacea ‘Victoria Blue’. Those are both typical bedding plants, maxing out at heights of around 18 to 24 inches. They are ubiquitous in garden centers every spring. For something different, try S. guaranitica or S. leucantha (technically tender perennials, but they can be grown as an annual).
Salvia guaranitica, or blue anise sage, is perhaps best known by its most popular cultivar, ‘Black and Blue’, which earned its name from its black stems and electric-blue, narrow-throated flowers. These flowers are set loosely along tall spikes that emerge from the 30- to 40-inch bush that quickly forms over the summer. Consider this South American native in lieu of summer-flowering shrubs in some areas, or use it to fill in after spring ephemerals or tall-stemmed spring-blooming bulbs die back into the ground.
Like blue anise sage, S. leucantha, or Mexican bush sage, adds a significant presence in a garden. As its common name implies, this plant is native to Central and South America, where it is perennial. Its fuzzy silver leaves hint at its drought tolerance, and when this quick grower matures into a 24- to 36-inch shrub in the summer, one could almost mistake it for a chaste tree (Vitex agnus-castus) or butterfly bush (Buddleia). Perhaps most noteworthy, its bicolor flowers are pubescent too, with a fuzzy white corolla and purple calyx.
A Sure Bet for Butterflies
Try Asclepias curassavica ‘Monarch Promise’. This plant, also known as blood flower or Mexican butterfly weed, is perennial in warmer climes, but it is easily started from seed indoors, and it can be used as an annual in colder zones.
The orange-and-red flowers are very similar to the hardy perennial Asclepias tuberosa (named Perennial Plant of the Year in 2017), so why bother with this variety? Answer: For its boldly variegated leaves. ‘Monarch Promise’ has long, narrow leaves that are dusky green along the midrib vein and edged with a bright, slightly creamy white margin. As leaves age in the sun, they can take on an irregular pink tinge as well.
Try an Annual Vine!
Instead of using Allamanda or Mandevilla as an annual vine, consider hyacinth bean (Lablab purpureus). While this plant is not often available at garden centers, it grows quickly from seed and it can cover fences, railings and arbors in weeks. Its rapid growth makes sense when one realizes the genus Lablab is a member of the Fabaceae, or bean family.
Further, hyacinth bean has a rich history of agricultural uses: it’s been harvested for its edible leaves, for livestock fodder and in many parts of India and China, the beans are cooked and used for foods and medicinal purposes. But take care! If they’re not properly prepared, the beans can be toxic, causing vomiting and convulsions. The safer bet is to use the deeply magenta-purple seed pods as an ornamental feature, just like the vine’s lavender flowers, which resemble those of sweet peas (Lathyrus).
An Annual That Doubles as a Houseplant
Streptocarpella – historically used as a houseplant – is now finding its way into outdoor planters more and more often. Called cape primrose, it’s related to African violets and it has similar fuzzy leaves and pure, purple blooms.
‘Concord Blue’ is a popular variety with blossoms that hover about the foliage like little blue hummingbirds. Try this plant in a tall urn or narrow planter outdoors. When the weather cools, bring it inside a sunny room.
An Alternative to Coleus in Shade
Coleus is an excellent plant, its foliage bringing bold colors to deeply shaded gardens where flowers are hard to come by. But if you want to try something new, consider Plectranthus Mona Lavender (‘Plepalila’). This plant, a member of the mint family, is a purple-leaved variety of Swedish ivy.
Like most mint-family plants, Mona Lavender has purple-stemmed spikes of lavender blossoms. But what makes this plant notable are the leaves—dark green with black-purple undersides—and its tolerance for deep shade. It also grows lightning fast, reaching bushy heights of 36 inches by August.
An Annual That Take Fall Frosts
Alyssum is an excellent go-to annual for its frost tolerance. In many climates, it can stay perky through Thanksgiving. But perhaps one wants to try a different annual that can weather some tough autumn or winter weather. Try the new varieties of EnduraScape verbena.
Available in purples, reds and white, EnduraScape are trailing plants that are reportedly hardy to 10 degrees (F). In gentler winters, they may even return the following spring.
Hints of Hawaii
Bring a little of Waikiki to your garden with Scaevola aemula, or fan flower. This prostrate, trailing annual (the perfect form for planters and window boxes) boasts electric blue, fan-shaped flowers and thrives with little water and high heat. Why do I mention Hawaii? Because annual scaevola is a compact, purple-blooming relative to the beach naupaka (S. taccada) that grows along the Hawaiian coastlines.
There are various legends about scaevola in Hawaii, most of which reference heartbreak and separation—inspired by the blossom that seems to be missing half of its petals.
Image credits: Salvia guaranitica 'Black and Blue' by Rhonda Fleming Hayes/CC BY-ND 2.0; Salvia leucantha by Mike Finn/CC BY 2.0; Asclepias 'Monarch's Promise' by Hort Couture; Hyacinth bean by Dwight Sipler/CC BY 2.0; Streptocarpella 'Concord Blue' courtesy of Proven Winners; Plectranthus Mona Lavender, Verbena EnduraScape Dark Purple and Scaevola aemula Blue Brilliance courtesy of Ball Horticultural Company
