Introduction
Imagine a plant with leaves so vibrant and textured they look like they were painted by an artist’s brush. Rex begonias are famous for their stunning foliage, featuring swirls of silver, deep purple, rosy pink, and emerald green. While many people think of these beauties strictly as houseplants, they are actually fantastic additions to your outdoor garden spaces. At Longfield Gardens, we love how these begonias can transform a shady corner into a focal point of color and texture.
Bringing your Rex begonias outside for the summer can give them a visible boost in health and vigor. The natural light and fresh air often encourage them to grow fuller and more colorful than they do indoors. This guide is for any gardener who wants to enjoy these tropical treasures on their porch, patio, or in their flower beds. We will cover how to choose the best spot, when to move them safely, and how to keep them thriving until the first frost.
While Rex begonias are tender plants, they are quite easy to care for once you understand their basic needs. For more on their foliage-focused growth habits, see our How to Grow Rex Begonia guide. With a little attention to shade and water, you can enjoy a spectacular foliage display all season long.
Can You Grow Rex Begonias Outdoors?
The short answer is a resounding yes. Rex begonias (Begonia rex-cultorum) are tropical perennials that originated in the forests of India. Because they naturally grow under the canopy of large trees, they are perfectly adapted to the shady parts of your yard. In most of the United States, they are grown as annuals or brought back inside when the weather turns cold.
If you live in a very warm climate, such as USDA hardiness zones 10 through 12, Rex begonias can stay outside year-round. For everyone else, they are treated as "summer guests." They appreciate the warmth and humidity of a typical American summer, which often mimics their native tropical environment better than the dry air inside our homes.
The key to success is remembering that these plants are sensitive to temperature and light. They do not like the cold, and they definitely do not like the harsh afternoon sun. As long as you can provide a warm, shaded spot, your Rex begonias will likely be the stars of your summer containers.
Choosing the Perfect Outdoor Location
Finding the right spot is the most important step in growing Rex begonias outside. In the garden, "location" usually refers to two things: light and protection from the elements.
The Importance of Shade
In their native habitat, Rex begonias live on the forest floor where they receive filtered or "dappled" sunlight. When you move them into your yard, you want to recreate this environment. Direct afternoon sun is too intense and will quickly scorch the delicate leaves, leaving behind brown, papery patches.
The best locations for Rex begonias include:
- A North-Facing Porch: This provides consistent, indirect light throughout the day without the risk of hot sun hits.
- Under a Covered Patio: The roof provides deep shade while the open sides allow for plenty of air circulation.
- Beneath Shady Trees: Large trees with high branches create a beautiful dappled light effect that Rex begonias love.
- The East Side of a Building: This spot allows for gentle morning sun, which is much cooler, followed by protective shade for the rest of the day.
Protection from Wind and Rain
Rex begonias have large, somewhat brittle leaves and stems that grow from a central rhizome (a thick, horizontal stem that sits near the soil surface). Strong winds can easily tear the foliage or snap the stems. Similarly, a heavy downpour can batter the leaves and splash soil onto the plant, which may lead to fungal issues.
Try to tuck your begonias into a sheltered area. For more ideas on planting in protected spaces, browse our Summer Flowers for Shade collection. If a big storm is in the forecast, it is a good idea to move your containers to a more protected spot until the weather clears.
Soil and Potting Requirements
While you can plant Rex begonias directly in the ground, most experts recommend keeping them in containers. There are a few practical reasons for this. First, it makes it much easier to move the plants if the sun shifts or if you need to bring them inside for the winter. Second, containers allow you to control the soil quality and drainage perfectly.
Understanding Drainage
"Drainage" simply refers to how fast water leaves the soil. Rex begonias are very sensitive to "wet feet," which means they do not like their roots sitting in soggy, stagnant water. If the soil stays too wet for too long, the rhizome can rot.
To ensure good drainage:
- Use a high-quality, lightweight potting mix. Many gardeners find that mixes designed for African violets or those containing peat moss and perlite work beautifully.
- Make sure your container has at least one large drainage hole at the bottom.
- Avoid using heavy garden soil in pots, as it tends to compact and trap too much moisture.
Selecting the Right Pot
Rex begonias have relatively shallow root systems that grow outward rather than deep into the earth. Because of this, shallow and wide pots (often called "azalea pots" or "bulb pans") are usually better than tall, narrow ones. A wider pot gives the rhizome plenty of room to creep along the surface and produce new leaves.
If you are shopping for more begonia options, our Hanging Begonias and Upright Double Begonias collections are good places to compare growing habits and forms.
Key Takeaway: Rex begonias thrive in "bright shade." They want plenty of light to keep their colors vivid, but they must be protected from direct, hot sun to prevent leaf burn.
When to Move Rex Begonias Outside
Timing is everything when it comes to moving tropical plants outdoors. Because Rex begonias are so tender, they cannot handle even a hint of frost. Even temperatures that are chilly but not freezing can cause the plant to drop its leaves or stop growing.
The 50-Degree Rule
A good rule of thumb is to wait until the nighttime temperatures are consistently above 50°F (10°C). In most parts of the country, this happens a few weeks after the last expected frost date in the spring. If you are still wearing a light jacket in the evenings, it is probably too cold for your begonias.
Hardening Off
You should never move a plant directly from a dim living room to a bright outdoor porch in one day. This causes "plant shock." Instead, use a process called "hardening off."
- Day 1-2: Place the plant outside in a fully shaded, sheltered spot for just two or three hours, then bring it back inside.
- Day 3-4: Increase the time to five or six hours, still keeping it in deep shade.
- Day 5-7: Leave the plant out all day. If the nights are warm enough, you can finally leave it out overnight.
This gradual transition allows the plant to toughen up its leaf cuticles and get used to the movement of the air and the change in light intensity.
Watering and Humidity in the Garden
Watering is the part of begonia care that requires the most attention. Outdoors, the wind and warmth will cause the soil in your pots to dry out much faster than it does indoors.
The Finger Test
The best way to tell if your Rex begonia needs water is the "finger test." Stick your finger into the soil up to the first knuckle. If the soil feels dry, it is time to water. If it still feels damp, wait another day. It is always better to underwater a begonia slightly than to overwater it.
How to Water
When you do water, try to aim the spout of your watering can directly at the soil rather than over the top of the leaves. Water sitting on the foliage can encourage powdery mildew, a fungus that looks like a dusting of white flour on the leaves. Watering early in the morning is also helpful because it gives any accidental splashes time to dry up before the cooler evening temperatures arrive.
Managing Humidity
Rex begonias love humidity. While our summers are often humid enough, if you live in a very dry climate, your begonia might struggle with crispy brown edges on its leaves. Grouping plants together can help create a small "microclimate" of higher humidity. However, avoid misting the leaves with a spray bottle, as this can lead to the same fungal problems mentioned above.
Feeding for Vibrant Foliage
Since Rex begonias are grown primarily for their leaves, they don't need a high-phosphorus "bloom booster" fertilizer. Instead, they appreciate a balanced, all-purpose liquid fertilizer.
During the peak growing season (late spring through late summer), you can feed your plants every two to three weeks. We recommend using the fertilizer at half the strength suggested on the package. This provides a steady stream of nutrients without the risk of "fertilizer burn" on the sensitive roots.
If you want to compare care and buying options, our Begonia Flower Bulbs for Sale collection is a helpful starting point. If your plant produces small pink or white flowers, you can leave them on if you like the look. However, many gardeners choose to pinch these flowers off. This tells the plant to put all its energy into growing those spectacular leaves rather than producing seeds.
Creative Ways to Use Rex Begonias Outdoors
One of the best things about Rex begonias is their versatility. Their colors are so varied that they can fit into almost any design scheme.
Container Recipes
Rex begonias make excellent "thrillers" or "fillers" in a container. Try these combinations:
- The Silver Screen: Pair a silver-leaved Rex begonia with purple-leafed oxalis and trailing silver dichondra.
- Tropical Heat: Mix a red or burgundy Rex begonia with a lime-green coleus and a dark-leaved sweet potato vine.
- Classic Shade: Combine Rex begonias with ferns and hostas for a lush, woodland look.
Mass Plantings
If you have a very shaded garden bed with rich, well-draining soil, you can plant several begonias together. Because they stay relatively low (usually 12 to 18 inches tall), they make a beautiful groundcover for a single season. Just remember that you will need to dig them up and pot them back up if you want to save them for next year.
What to Do Next:
- Check your zone: Verify your last frost date and wait for nights to stay above 50°F.
- Choose a pot: Find a wide, shallow container with good drainage.
- Select a spot: Identify a north-facing or deeply shaded area protected from wind.
- Prepare your soil: Use a light, peat-based potting mix.
Bringing Rex Begonias Back Inside
As summer draws to a close, you need to keep an eye on the thermometer. Once nighttime temperatures start dipping back toward 50°F, it is time to bring your begonias back indoors.
The Transition
Just as you hardened the plants off to go outside, they need a little time to adjust to coming back in. The air inside your home is much drier and the light is much lower.
- Check the plant thoroughly for any "hitchhikers" like spiders or aphids. A gentle spray with a garden hose can help knock off any pests.
- Place the plant in a bright window, but away from any direct heat vents or drafty doors.
- Expect some leaf drop. This is normal! The plant is reacting to the lower light levels. As long as the rhizome remains firm and healthy, new leaves will grow back that are better adapted to the indoor light.
Winter Dormancy
Sometimes, a Rex begonia will go into a period of dormancy during the winter. It might lose most of its leaves and look like it is struggling. If this happens, reduce your watering significantly—just enough to keep the soil from becoming bone-dry—and stop fertilizing. For seasonal timing and delivery details, review our Shipping Information page. When the days get longer in the spring, you will see new little leaves emerging from the rhizome, signaling that it is ready to start the cycle again.
Managing Common Outdoor Challenges
While gardening should be a rewarding experience, it is helpful to know what to do if your plant doesn't look its best. Most issues with Rex begonias have very simple fixes.
Sunburn and Leaf Scorch
If you notice brown, crunchy patches in the middle of the leaves, your plant is likely getting too much sun. The fix is easy: move the pot further into the shade. You can trim off the damaged leaves to keep the plant looking tidy; new ones will eventually take their place.
Wilting
If your begonia is wilting, it is usually because the soil is either too dry or too wet. First, check the moisture with your finger.
- If it’s dry: Give it a deep soak until water runs out the bottom of the pot.
- If it’s soggy: Stop watering immediately and move the pot to a spot with better air circulation to help the soil dry out. Check to make sure the drainage hole isn't blocked.
Pests
Outdoors, you might occasionally see slugs or snails, which love the fleshy leaves of begonias. Keeping your pots on a table or stand rather than directly on the ground can help prevent this. If you see tiny holes in the leaves, look for these slow-moving visitors in the early morning or evening and simply move them away from your plants.
Summary of Outdoor Care
At Longfield Gardens, we want you to feel confident that you can grow beautiful plants with ease. Rex begonias are a perfect example of a plant that offers a high reward for just a little bit of specialized care. By focusing on shade, drainage, and temperature, you can enjoy these stunning foliage plants as part of your outdoor living space.
- Light: Stick to bright, indirect light or dappled shade.
- Water: Use the "finger test" and avoid getting water on the leaves.
- Temperature: Only keep them outside when nights are above 50°F.
- Soil: Use a light, well-draining potting mix in a shallow container.
Whether you are a beginner or an experienced gardener, adding Rex begonias to your patio or porch is a wonderful way to bring sophisticated color to the shady parts of your yard. If you want to learn more about our quality standards and support, visit our About Us page. We are here to help you every step of the way, from selecting the right varieties to providing the tips you need for a successful growing season.
"The beauty of Rex begonias lies in their diversity. There is a variety for every color palette, making them one of the most versatile foliage plants for the shade garden."
FAQ
Can Rex begonias take any direct sun?
Rex begonias can typically handle an hour or two of very early morning sun, which is gentle and cool. However, they should be protected from direct sunlight from 10:00 AM onwards, as the heat and intensity will quickly burn their leaves.
Why are the edges of my outdoor begonia leaves turning brown?
Brown edges are usually a sign of low humidity or underwatering. If the soil is dry, water the plant more frequently. If the soil is moist, try moving the plant closer to other plants to increase the local humidity level around the leaves.
Should I plant Rex begonias in the ground or in pots?
While they can grow in the ground in well-drained, shady beds, pots are usually better. Containers provide superior drainage, prevent soil from splashing onto the leaves, and allow you to easily move the plants indoors when the weather turns cold.
How often should I fertilize my Rex begonias when they are outside?
During the active growing season in spring and summer, you can fertilize every two to three weeks with a balanced liquid fertilizer diluted to half-strength. Stop fertilizing in late autumn and winter when the plant's growth slows down naturally.
