Growing the Perfect Rex Begonia: Tips and Tricks

Rex begonias offer a cinematic display of dramatic foliage. You’ll find a variety of variegated leaves with streaks, spirals, and veins in striking colors like pink, purple, green, burgundy, and silver. Some leaves are puckered, others are velvety smooth. The "Escargot" is a popular B. rex-cultorum cultivar with a snail-like curl in the middle of each leaf. The leaves reflect blue due to specialized chloroplasts called iridoplasts.

Rex begonias make beautiful houseplants. Collecting a variety of these exotic lovelies with different leaf variations is a fun and interesting hobby. Use an African violet potting soil — rex begonias prefer this light, airy, well-drained soil and don’t thrive in heavier mixes. Terrariums are ideal spots to grow rex begonias. Plants clustered together increase the humidity levels, and these plants love it. Indirect light is best.

Begonia rex is a perennial in zones 10 through 12. If you live in an area where the daytime temperatures in the summer aren’t extreme, these plants make a dazzling addition to a front porch or patio garden. Protect them from wind and hot sun, and make sure they have proper air circulation. Repot as needed, especially while the plant is maturing. The rex begonia doesn’t mind being root-bound.

Whether you’re growing a rex begonia indoors or outdoors, direct sun is its enemy. Bright, indirect light is beneficial, especially if you’re hoping for blooms. The rex begonia is a tropical plant and won’t thrive in hot temperatures or cooler ones below 60 degrees. Furthermore, major temperature changes will damage its leaves. Patio plants prefer bright morning sun. Rotate the pot regularly if the sunlight comes from one side.

Although the rex begonia prefers high humidity, misting can lead to powdery mildew. Instead, place the plant in its container on a tray of pebbles covered in water. This increases the humidity around the plant. Setting the container on the pebbles prevents the roots from becoming water-soaked, which can kill the plant. Allow the top 50% of container soil to dry between waterings or wait until the leaves start to slightly droop. Reduce the amount of water during the winter.

Monthly feedings from April through August are all a rex begonia requires. Most growers recommend a nitrogen-rich, soluble houseplant food with a concentration of 180 parts per million nitrogen. If your plants look a bit unhealthy, try fertilizing twice per month during the growing season. Keep the colors and foliage looking bright and beautiful by pinching off any flowers that appear in the winter; this encourages all the nutrition to go directly to the leaves.

Although the flowers are not the main reason gardeners and plant lovers choose the rex begonia, some are fans of its delicate, tiny blossoms. They don’t bloom often, but when and if they do, they’re usually pink or white. Those blooming begonias you see at the nursery are more likely wax, tuberous, or angel wing begonias.

Few plants offer such a variety of leaf types and sizes. Miniature rex begonias display the same colorful foliage as their larger peers, but they only grow to about eight inches tall. The Begonia "Regal Minuet" is a popular miniature variety that offers dark rose-colored foliage. These smaller versions are excellent choices for adding color and texture in terrariums.

If you prefer dramatic greenery with tons of color and a mix of leaf sizes, you’ll find the perfect plant among the begonia rex varieties. The rex begonia usually reaches a height of 12 to 18 inches and 18 inches wide when it matures. Most varieties have leaves that grow to between four and nine inches long, and five inches wide. One of the more compact, small-leaved varieties is the ‘Silver Limb,’ with metallic silver foliage and a purplish-red underside. If you’re seeking to add texture rather than color, consider the "River Nile" variety, which produces bronze-edged, ruffled leaves.

Creating new rex begonia plants is not a complex process. Using a single leaf, you can grow new plants for your personal enjoyment or give away as gifts to fellow plant lovers, family members, friends, or co-workers.

• Choose a healthy leaf and cut it off from the base of the plant.
• Cut off the leaf’s stalk.
• Create small slashes near the leaf veins of the plant.
• Pin the leaf down into a growing medium or compost.
• Soon, you’ll see tiny new plants popping up from the soil.

You can also try planting four-inch stems directly into a growing medium. Before you do, it helps to first dip the cut ends into a rooting hormone.