For shady spots in northern gardens, begonias are a favorite choice. They grow well with just a bit of sun, come in a wide range of bloom colors, leaf types and sizes and are relatively easy to grow.
So Many Begonias
The genus Begonia includes more than 2,000 species and thousands more cultivars. Home gardeners are most familiar with three types that are grown as annuals or houseplants: fibrous, tuberous and rhizomatous. A fourth type, Begonia grandis, cannot withstand our cold winters and are grown as perennials in USDA Hardiness Zone 6 and higher.
Fibrous begonias include wax and angel-wing begonias and other popular annuals. They have waxy leaves and lots of blooms. Popular cultivars include Dragon Wing or the Cocktail series. They look terrific in hanging baskets or containers,
Tuberous begonias are all about the bloom, with single and double flowers and tons of color options, from pretty pale yellows to deep, deep red. They make a standout addition to shady patio planters, window boxes or any shady spot you’d like to brighten with color.
Rhizomatous begonias are grown chiefly as foliage houseplants, though they really make a statement in containers with their swirled, veined, multicolored leaves. Rex types are the most popular subtype of rhizomatous begonia.
What a Begonia Wants
These are not difficult plants to grow indoors or out. In containers, they like a loose, well-drained potting mix, according to the American Begonia Society. For sun, they love getting a little morning sun or some dappled light throughout the day, but they can take a lot of shade. These are warm season plants (most are native to South America and southern Africa) so they do best when nighttime temperatures are above 55 degrees. Don’t rush to plant your begonias!
They grow best with regular but not excessive watering and they are prone to rot if the roots are sitting in water. Like all annuals, they need a regular, light application of fertilizer to bloom continually.
Keeping Them Through Winter
While it’s fun to try different types of begonias each year, you can overwinter begonias in Minnesota. Wax begonias are the easiest: just leave them in their containers and bring them in the house. (You may want to isolate the plants for a few weeks in case they brought insects in with them. Or treat them with an organic insecticide, such as NEEM oil, before bringing them in.) Indoors, place them in a bright window.
Tuberous begonias can be stored through the winter in the same way people store dahlias and gladiolus. Dig the tubers before there is a frost. Spread the tubers on a shelf or the ground to dry out and cure for a week, then pack them in paper bags or boxes with some kind of dry material. This blog post has some great tips for storing begonias.
Enjoy valuable northern gardening tips all year long—join the hort!