What plant thrives indoors, shrugs off low humidity, and blooms all winter in bold shades of white to pink to red? Surprise! It’s wax begonias!
Also called fibrous begonias, these familiar bedding plants have large, round succulent leaves in either lime green or a beautiful burgundy- or bronze-red. Flowers have fleshy petals surrounding a bright yellow cluster of stamens. Plants grow to a height of about six to twelve inches. They tend to flop, creating a solid mass of color, and even trailing over walls and container edges.
Wax begonias are usually considered summer annuals. It’s true that they do well in our gardens, given light shade or (preferably filtered) sun. Space them a foot apart in soil high in organic matter and keep the roots evenly moist. Happily, pests are usually not a problem—even the deer tend to leave them alone!
Well, these carefree outdoor plants are just as easy to grow indoors.
Treat them as you would any houseplant. Size the container to the plant, and use a soil-free potting mix. While the water-retentive plants can go a while between waterings, they prefer to stay damp, especially when growing in full sun. While they bloom in the shade outside, indoors a sunny window is best. Be sure to leave some space between the leaves and the glass to avoid burning the foliage. Regular feeding keeps the flowers coming. If they get too leggy, just pinch them back. As a bonus, the stem ends root readily in a cup of water.
The only real problem is that the spent flowers drop their petals on the floor where they must be swept or vacuumed away. That’s a small price to pay for flowers in January!
While the plants are listed as tender annuals, they seem to keep growing indefinitely. If they do decline, replacement seedlings are cheap and easy to buy during the growing season.
Perhaps the easiest way to enjoy these flowers year round is to grow them in containers. Start them on the patio in early summer. When frost threatens in the fall, bring them indoors and continue to enjoy their tropical appearance while the snow flies.
Article and photo by Leslie Holzmann, Colorado Master Gardener
Pikes Peak Area Garden Help 
April 29, 2012 at 7:43 am
Hi there! I’m a Colorado Springs resident with a wax begonia that I frequently take outside during the day to soak up the sunshine on warm days (since I don’t have any super-sunny windows indoors). And it’s been thriving that way, but last week, I came home from running a few errands to find crunchy, damaged leaves on it following an unexpected rain and hail storm! Eeek! Any tips for nursing it back to health? Thanks!
April 30, 2012 at 10:14 am
Happily, there is hope for your begonia. Once you’re sure what parts of the plant are really dead, just prune it back to the living tissue. Then keep doing what you’re doing. If your begonia was happy before, it will revive and be happy again. Don’t feed it until it shows signs of new growth.
You may need to remove some healthy leaves eventually to balance the shape of the plant, but wait a bit to do that. Right now, the healthy leaves are needed to photosynthesize food for the plant’s regrowth. I realize that hail isn’t exactly the best pruning tool, but begonias indoors will eventually get fairly leggy, so pruning it back is a good thing–it keeps your plant bushy and attractive.
If you end up cutting off long branches, you might try rooting them in a jar of water or moist sand.
Finally, while good light is essential, be careful with the sunshine. Wax begonias are shade plants. Morning sun and/or light shade is best.
May 3, 2012 at 1:01 pm
Thank you for all the great advice! Good to know that my plant needs more shade…this explains why the leaf edges got crispy looking. Oops! I will make sure it has only a little morning sun from now on.