Even when summer gardens wind down, the hardy begonia (Begonia grandis) is still going strong in most shade gardens where it’s planted. In fact, this herbaceous perennial generally blooms from about midsummer through October until the first frost. This long bloom time is just one of many reasons gardeners appreciate the hardy begonia so much. Because the hardy begonia thrives in part shade, it’s perfect as an understory plant. (That means you could include hardy begonias around the base of your trees and shrubs or even plant them in the shade of taller perennials next season.)
Hands down, the look and feel of this beauty’s foliage is what really sets it apart—asymmetrical, olive green leaves are shot through with bright red veins. And when the wind blows just right? These striking leaves reveal nearly metallic red undersides. Best of all, hardy begonias don’t require much care and are fairly deer-resistant, too.
Meet the hardy begonia
The hardy begonia (or Begonia grandis) is just one of the more than 2,000 plant species in the Begoniaceae family. Depending on the hardy begonia cultivars you choose, its inch-wide blooms may be pink or white. (For instance, while some hardy begonia plant types like Begonia grandis ‘Heron’s Pirouette’ feature pink flowers, Begonia grandis ‘Alba’ puts out delicate white flowers instead.)
Hardy begonias originally came from Asia’s higher altitude regions and, as a result, they perform well despite cold weather. These cold-and-shade-tolerant plants can grow up to two feet tall with about a two-foot spread.
In addition to their clusters of nodding flowers and arresting green-and-red leaves, hardy begonias also produce papery, angular-looking seed pods which provide their own bit of visual interest. And, thanks to these pods, Begonia grandis self seeds.
Interestingly, self-propagation in hardy begonias can also take place without seeds. Fall’s shorter days trigger hardy begonias to produce pea-sized bulbils. (These tiny bulblets form along leaf axils—where leaf stems join up with plant branches.) In time, the bulbils drop off and hide out in the soil until the following spring when they’ll grow into new, carbon copies of the parent plant.
How hardy is Begonia grandis?
True to its name, the hardy begonia is a trooper when temperatures begin to drop. It’s generally winter hardy to USDA zones 6 or 7 and will survive in climates as warm as zone 9. Their foliage can withstand temperatures only down to the mid-20s (about -5 degrees C), so in cold-winter climates, hardy begonias eventually will go dormant and the foliage will die back to the ground.
Where to grow the hardy begonia
Remember, if you live in zones 6 through 9, hardy begonias planted outdoors typically die back for the winter but will reappear in late spring. If you have a high, shady spot with rich soil, you’re all set, since the hardy begonia thrives in well-drained soils and partial to full shade. Just keep in mind that your begonias’ floral display may be more impressive if you can position your plants so that they get a couple of hours of morning or evening light—but not harsh, midday sun—each day.
How to plant
Want to give your hardy begonias the best possible start? First, take a good look at your planting site and be prepared to make any adjustments as needed to meet your new plants’ soil requirements. Good drainage is essential, and, without it, you could lose your hardy begonias to root rot.
If you are planting them as bedding plants, you can space individual plants—or small groupings of your hardy begonia plants—a couple of feet apart. After you’ve worked any new organic matter into your planting site, dig holes deeply enough so that the soil level of each bedding plant is even with the soil level in your garden.
If, on the other hand, you are starting hardy begonias from bulbils, your best bet is to start them indoors in pots and then plant them outside when winter has passed. You can also plant them directly in the garden in the spring.
Great companions to grow with hardy begonias
Hardy begonias play nicely with many shade annuals and perennials (you’ll find some our favorite shade-loving perennial flowers here), and gardeners have long mixed clumps of these begonias in with their ferns and hostas for an extra pop of color. You might also try planting some hardy begonias in amongst coral bells to help attract and fuel up passing hummingbirds.
Care tips for the hardy begonia
In early spring, you can kick-start the growth of your hardy begonias by adding a layer of well-rotted compost to their garden bed. By early summer, you should add an inch or two of mulch around your begonias. (This will help to keep plant roots cool and conserve moisture during dry spells occurring in the hottest part of the season.) Finally, once flowering starts, periodically deadhead spent blooms to encourage flowering to continue.
Although hardy begonias are fairly trouble-free, here are a few troubleshooting tips just in case:
- Poor flowering—Most hardy begonias begin flowering around July. If yours don’t, they might be getting a little too much shade where they’re located. Alternatively, they might need a little extra phosphorus and other bloom-boosting nutrients. Applying a natural, organic fertilizer can help.
- Yellowing foliage—In cooler climates during the fall, it’s normal for hardy begonias to turn yellow and begin to die back. However, if your plants are yellowing in, say, early summer, then there’s something else going on. Most often, poor drainage or overwatering are to blame. Cut back on watering and mix organic matter into the soil to improve aeration.
- Disease problems—Too much standing water in the soil also can contribute to root rot. If you catch it early enough, you may be able to salvage plants by allowing the soil to dry out a bit and by using clean, sharp pruners to remove any diseased portions of your plants.
- Insect pests—Occasionally, you might notice thrips, mites, mealybugs, or other insect pests feeding on your hardy begonias. Hand-picking works well for small infestations. For larger numbers, you can opt for an insecticidal soap, but use it sparingly, as it may affect beneficial insects, too.
Overwintering the perennial begonia
If you live in a cold climate, add two to three inches of fresh mulch to the planting bed in late fall to help insulate and protect your hardy begonias during the coming winter. If your begonia bed will be overly exposed to cold and drying winter winds, you might also want to erect a windbreak nearby.
Made in the shade
Pretty—and pretty tough!—hardy begonias are fantastic additions to any shade garden. As long as it’s provided with moist, nutrient-rich soil which drains adequately, the hardy begonia can serve as a good ground cover by itself or it can be mixed with other shade-lovers. Hardy begonias are deer-resistant, cold-tolerant, and hardy in zones 6 through 9. What’s more, they afford bumble bees, hummingbirds, and other crucial pollinators with a bevy of blooms from about July through the fall.
Now that you’ve learned how easy they are to plant and care for—not to mention how readily they’ll self-propagate—any hardy begonias you plan to add to your landscape will surely have it made.
For more great shade plants, please visit the following articles:
- Flowering perennials for the shade
- Grow the polka dot begonia
- Shade-loving shrubs that flower
- Shade groundcover choices
- Begonia Gryphon
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