Why grow rex begonia?
The great thing about rex begonias (Begonia rex-cultorum) is that there's a huge variety of colors and patterns, leaf shapes, sizes and textures to choose from. They do flower but those dainty blooms aren’t the main attraction. They can also be grown indoors or out! The collection of rex begonias above showcases some of the gorgeous foliage you can find. Scroll down to see a photo gallery of our favorites that shows even more variety. (Just a note, these are the colors you can expect from mature specimens. Young plants aren’t always as colorful when you first get them, but are worth the wait!) While growing rex begonias is usually pretty easy, I talked with a few expert growers to get their advice and ensure success with these foliage beauties.
How to grow rex begonias indoors
Rex begonias are tender perennials that are only cold hardy in USDA zones 10 to 11, they are commonly grown as an annual or indoor plant. They're great indoor plants that thrive in a bright, north- or east-facing window or under lights in a pot filled with good draining potting mix. Water regularly after the potting mix is dry. If the edges of the leaves are getting crispy, your plant probably isn’t getting enough moisture.
Rex begonias have a reputation for being finicky indoors. Don Miller of Steve’s Leaves says that humidity can often be the problem, especially in winter. He recommends grouping your indoor plants together to create a more humid environment. In addition, you can put a layer of pebbles into a water-filled tray and set the begonia pots on top of the pebbles, out of the water. A small room humidifier nearby can also help. You can even grow begonias in the bathroom as long as there’s a sunny window for them. One last tip for raising humidity is to lower the thermostat — the warmer a room is, the dryer the air.
How to grow rex begonias outdoors
Planting rex begonias outdoors is not just a good idea, it’s a great one! A sheltered spot like the porch you see above is a great spot for growing rex begonias along with other shade-loving companions, such as caladium (Caladium hybrid) and oxalis (Oxalis triangularis). The light is gentle and the wind and rain won’t damage leaves or cause the potting mix to get soggy. You'll want to place your begonias in part to full shade — too much sun can burn the leaves.
Being outdoors means potting mix can dry out faster so keep an eye on moisture levels so plants don't wilt. Repeated wilting can weaken the plant and set growth back. To see if it's time to water, insert your finger into the potting mix up to the first knuckle and if it feels dry it's time to water.
Rex begonia tips from a pro
It can take several years to grow larger plants like the ones above. For more of an instant impact rex, give the Jurassic™ series a try. They're usually pretty big to start with and vigorous growers. Joan Mazat, a begonia specialist at Ball Horticulture, the company that introduced the Jurassic series, suggests growing rex begonias in containers rather than in the ground. She’s found that soil splashes on the foliage, and the plant’s mounded habit holds moisture in, creating a chance for rot or fungal disease to take hold and ruin the show. In addition, Joan uses a liquid plant food every seven days in summer when she’s watering more frequently and every 14 days in spring and fall.
Try these rex begonias
There are hundreds of rex begonia species and hybrids. We've picked a few of our favorites in the gallery and if you're looking for a good place to buy plants, check out the trusted sources below.