Introduction
There is nothing quite like the sight of a shady porch or garden bed coming to life with the lush, tropical colors of begonias. Whether you are captivated by the rose-like blooms of tuberous varieties or the striking patterns of rex begonia foliage, these plants are a favorite for a reason. They offer a continuous show of color from early summer right through the first frost, making them one of the most reliable choices for any garden.
If you are wondering, "Can I plant begonia outside?" the answer is a resounding yes. These versatile plants thrive in outdoor settings across the United States when given the right conditions. At Longfield Gardens, we have spent years trialing different varieties to ensure that home gardeners can enjoy professional-level results with ease.
In this guide, we will walk through everything you need to know to transition your begonias to the great outdoors. From timing your planting perfectly to choosing the best spot for shade-loving varieties, we have you covered. You will learn how to care for these beauties so they remain vibrant and healthy all season long.
Successful outdoor begonia gardening simply requires a bit of patience for warm weather and a focus on well-draining soil.
Understanding Your Begonias
Before you head out to the garden with a shovel, it is helpful to know which type of begonia you are working with. While they all share a love for warmth, different types have slightly different preferences for light and moisture.
Tuberous Begonias
These are the showstoppers of the begonia world. They grow from a thick, potato-like tuber and produce large, multi-petaled flowers that often resemble roses or camellias. Tuberous begonias come in both upright and trailing forms. The trailing types are perfect for hanging baskets, while the upright ones look spectacular in window boxes or flower beds.
Wax Begonias
Wax begonias are the workhorses of the summer garden. They have small, succulent leaves that are either green or bronze. They are incredibly resilient and can handle a bit more sun than their tuberous cousins. You will often see these used as "bedding plants" to create a colorful border along a walkway or around a flagpole.
Cane and Rex Begonias
Cane begonias, often called "Angel Wing" begonias, are known for their upright, bamboo-like stems and spotted leaves. Rex begonias are grown primarily for their incredible foliage, which can feature swirls of silver, purple, pink, and deep green. While these are often kept as houseplants, they absolutely love spending the summer months outdoors in a protected, shady spot.
Key Takeaway: Identifying your begonia type helps you pick the perfect spot. Tuberous and Rex types prefer more shade, while Wax begonias are the most sun-tolerant.
When Is the Best Time to Plant Begonias Outside?
Timing is the most important factor when moving begonias outdoors. Because they are tropical and semi-tropical plants, they have no tolerance for frost. Planting too early is a common mistake, but it is an easy one to avoid with a little bit of patience.
For help with timing in your area, check the Hardiness Zone Map before you plant. The Shipping Information page also explains how Longfield Gardens schedules orders by zone.
Wait for the Right Temperature
You should only plant begonias outside when the danger of frost has completely passed. However, "no frost" is only the first step. Begonias really start to thrive when nighttime temperatures are consistently above 50°F. If the nights are still dipping into the 40s, the plants may sit still and refuse to grow, or their stems may become soft and damaged.
For tuberous begonias, the soil temperature is also important. They prefer soil that has warmed to at least 60°F. If you live in a northern climate, this usually means waiting until late May or early June. In the southern US, you might be able to plant as early as March or April.
Hardening Off Your Plants
If you started your tubers indoors or bought plants from a greenhouse, they need a "warm-up" period before they live outside full-time. This process is called hardening off.
Start by placing your plants in a sheltered, shady spot outside for just two or three hours during the day. Bring them back inside before the sun gets too hot or the evening air cools down. Gradually increase their time outside over the course of a week. This allows the leaves to thicken up and adjust to the breeze and shifting light.
What to Do Next: Timing Checklist
- Check your local "average last frost date."
- Monitor the 10-day forecast for nighttime lows above 50°F.
- Ensure the soil feels warm to the touch, not cold and clammy.
- Prepare a staging area for hardening off your plants over 7 to 10 days.
Choosing the Right Location for Outdoor Begonias
Once the weather is right, you need to find the "right place" for your plants. Begonias are famous for loving the shade, but "shade" can mean many things in a home landscape.
If you want a closer look at where begonias perform best, see Where Do Begonias Grow?. You can also read Where to Plant Begonias for more guidance on picking a shady spot.
Light Requirements
Most begonias prefer filtered light or dappled shade. Imagine the light under a tall tree with a high canopy—that is the "sweet spot."
- Morning Sun: Many begonias enjoy 2 to 4 hours of gentle morning sun. The light before 11:00 AM is usually cool enough not to scorch the leaves.
- Afternoon Shade: Protection from the harsh afternoon sun is essential. Direct sun between 1:00 PM and 5:00 PM can cause the leaves of tuberous and rex begonias to turn brown and "crispy" at the edges.
- Dense Shade: While they love shade, they still need light to produce flowers. If a spot is so dark that moss is the only thing growing there, your begonias might become "leggy" (tall and thin) and produce fewer blooms.
Drainage and Soil Quality
Begonias are very sensitive to "wet feet." This means they do not like their roots sitting in water for long periods. Drainage refers to how fast water leaves the soil. If you have heavy clay soil that stays soggy after a rain, it is best to plant your begonias in raised beds or containers.
For the best results, use a light, airy soil mix. If you are planting in the ground, you can improve your soil by mixing in some compost or finely shredded bark. This adds nutrients and creates air pockets that help the roots breathe.
Protection from the Elements
Begonias have relatively brittle stems, especially the large-flowered tuberous varieties. A heavy thunderstorm or a very windy afternoon can snap the stems or bruise the delicate petals. Whenever possible, plant them in a spot that is sheltered from the prevailing wind. A covered porch, a courtyard, or a spot nestled near the house is often ideal.
Key Takeaway: The perfect begonia home has morning sun, afternoon shade, and soil that never stays soggy. Protection from wind will keep the heavy blooms from snapping.
How to Plant Begonias in the Garden
Planting in a garden bed provides begonias with more room for their roots to spread out. This often leads to larger plants and a more dramatic display.
Step 1: Prep the Soil
Loosen the soil to a depth of about 6 to 8 inches. This is the perfect time to mix in a little compost. Begonias are not heavy feeders at the very beginning, but they appreciate the organic matter.
Step 2: Spacing
Space your begonias 8 to 12 inches apart. This might seem like a lot of space when the plants are small, but they will quickly fill in. Good spacing allows air to circulate around the leaves, which helps prevent issues like powdery mildew (a white, dusty-looking fungus).
Step 3: Planting Depth
If you are planting a begonia that is already in a pot, plant it at the same depth it was in the nursery container. If you are planting bare tubers directly in the garden, place them about 1 inch deep.
Pro Tip: Tuberous begonia tubers have a "hollow" or indented side. Always plant that indented side facing up. This is where the sprouts will emerge.
Step 4: Initial Watering
Water the plants gently after planting. This helps settle the soil around the roots and removes any large air pockets. Be careful not to wash away the soil covering the tubers.
Planting Begonias in Containers and Hanging Baskets
Hanging Begonias are arguably the best way to enjoy begonias in a controlled setting. Containers allow you to manage the soil quality and move the plants if they are getting too much sun or wind.
Choosing the Right Pot
Ensure your container has at least one drainage hole in the bottom. Begonias in pots without drainage are very likely to suffer from root rot. For a single begonia plant, a 10-inch pot is usually sufficient. For a large hanging basket, you can plant three trailing begonias in a 12-inch or 14-inch container for a full, lush look.
Using the Best Potting Mix
Avoid using "garden soil" from your yard in pots. It is too heavy and will pack down, stifling the roots. Instead, use a high-quality, all-purpose potting mix. These mixes are designed to be lightweight and provide the drainage begonias crave.
Planting Technique
- Fill your pot with moist potting mix, leaving about 2 inches of space at the top.
- If using tubers, space them about 3 to 4 inches apart.
- If using started plants, gently loosen the roots if they are circling the pot.
- Set the plant so the top of the root ball is about 1 inch below the rim of the pot.
- Fill in with soil and press down very gently.
Key Takeaway: Containers offer the most control. Use a lightweight potting mix and ensure there are holes in the bottom of the pot for water to escape.
Caring for Outdoor Begonias Throughout the Season
Once your begonias are settled in, they are relatively low-maintenance. Getting into a simple routine will keep them blooming from July all the way until the frost arrives.
For broader growing advice, What Zone Do Begonias Grow In? is a helpful next stop.
Watering Correctly
The goal is to keep the soil "evenly moist." This means the soil should feel like a wrung-out sponge.
- Check the soil: Stick your finger about an inch into the soil. If it feels dry, it is time to water. If it feels wet, wait another day.
- Water the soil, not the leaves: Try to pour water directly onto the soil at the base of the plant. Getting the leaves wet frequently can lead to leaf spots or fungal issues.
- Morning is best: Watering in the morning allows any moisture on the foliage to dry out during the day.
Fertilizing for More Blooms
Begonias are "hungry" plants once they start blooming. To keep the flowers coming, use a balanced, water-soluble fertilizer every two weeks. Look for a fertilizer where the three numbers on the label (like 10-10-10) are roughly equal. This provides a good mix of nutrients for both leaf growth and flower production.
Deadheading and Grooming
"Deadheading" is the process of removing faded flowers. Many modern begonias are "self-cleaning," meaning the old flowers fall off on their own. However, if you see spent blooms hanging on the plant, pinching them off will keep the plant looking tidy. It also encourages the plant to put its energy into new flowers rather than producing seeds.
If your plants start to look "leggy" or too long mid-summer, do not be afraid to pinch back the stems. Pinching off the top inch of a stem encourages the plant to grow side branches, resulting in a bushier, fuller plant.
What to Do Next: Summer Care Routine
- Check soil moisture every morning (especially for pots).
- Feed with a balanced fertilizer every 14 days.
- Remove any yellowing leaves or spent blooms once a week.
- Monitor for pests like slugs or snails, which love the succulent leaves.
Managing Common Begonia Challenges
Even with the best care, you might run into a few hurdles. Fortunately, most begonia issues are easy to fix once you know what to look for.
Powdery Mildew
This looks like a light dusting of flour on the leaves. It usually happens when the air is humid and there isn't enough air circulation. To prevent this, make sure your plants are not crowded too closely together. If you see it starting, you can prune away the affected leaves and move the plant to a slightly breezier spot.
Dropping Buds
If your begonia is producing buds but they fall off before they open, it is usually a sign of stress. This can be caused by a sudden heatwave, or by the soil getting too dry. Consistent watering is the best "fix" for bud drop. Ensuring the plant is protected from the hot afternoon sun will also help.
Pests
Slugs and snails are the most common visitors to outdoor begonias. They love the moist, shady environment where begonias thrive. You can protect your plants by using snail bait or by simply checking the plants in the evening and removing any pests you find.
Mealybugs and aphids can sometimes appear, especially on cane begonias. A gentle spray of water or an insecticidal soap (following the label instructions) usually takes care of these small insects.
Safety Note for Pets and Children
It is important to note that begonias contain calcium oxalate, which can be toxic if eaten. This is particularly true for the underground parts like the tubers. Keep your plants out of reach of curious pets or small children who might be tempted to take a bite. If ingestion occurs, it can cause irritation in the mouth and throat, so it is always best to consult a professional.
What to Do When the Season Ends
As autumn arrives, you have a few choices for your begonias. Because they are not hardy in most of the US (except for Zones 9-11), they will not survive the winter outdoors.
Treating Them as Annuals
Many gardeners choose to treat begonias as annuals. Once the first light frost hits and the leaves turn black, you can simply remove the plants and add them to your compost pile. This is the simplest approach and allows you to try new varieties the following year.
Saving Tuberous Begonias
If you have a favorite tuberous begonia, you can save the tuber to plant again next spring.
- Before the first hard freeze, dig up the tuber.
- Cut the stems back to about an inch above the tuber.
- Let the tuber dry in a cool, dark place for a few days.
- Once dry, shake off the excess soil and store the tuber in a paper bag filled with peat moss or sawdust.
- Keep the bag in a cool, dark spot (like a basement) where the temperature stays around 40-50°F.
If you are unsure about timing, Can I Bring My Begonias Indoors? explains when to move plants inside.
Bringing Rex or Cane Begonias Indoors
Rex and cane begonias make excellent houseplants. Before the temperatures drop below 50°F, bring them inside and place them in a bright window. They may lose a few leaves as they adjust to the lower humidity of your home, but they will usually bounce back within a month.
How to Care for Begonia Rex is a useful guide if you want to keep those foliage types thriving indoors.
Key Takeaway: You don't have to say goodbye to your favorite begonias. Save tubers in a cool, dry place or bring foliage types indoors to enjoy as houseplants all winter long.
Conclusion
Planting begonias outside is one of the most rewarding ways to add consistent, vibrant color to the shady corners of your yard. By simply waiting for the warm weather of late spring and choosing a spot with well-drained soil and dappled light, you are setting yourself up for success. Whether you choose the massive blooms of tuberous varieties or the easy-going nature of wax begonias, these plants will reward you with beauty all season long.
We hope this guide makes you feel confident in bringing these tropical treasures into your garden. Remember that gardening is a journey, and every season is an opportunity to learn what works best in your unique space.
- Wait for warmth: Ensure nighttime temperatures are consistently above 50°F.
- Prioritize drainage: Use pots with holes or amend garden soil with compost.
- Respect the shade: Provide protection from the harsh afternoon sun.
- Feed and water: Keep soil moist and fertilize every two weeks for maximum blooms.
From our gardens to yours, we at Longfield Gardens wish you a spectacular and colorful growing season. If you are ready to start your begonia journey, the first step is as simple as picking your favorite color and waiting for those warm spring days to arrive.
"A well-placed begonia can turn a dark, forgotten corner into the highlight of your entire landscape."
FAQ
Can begonias grow in full sun?
Most begonias prefer shade or partial shade, but Wax Begonias are quite sun-tolerant. In cooler northern climates, many varieties can handle more sun if they are kept consistently moist. However, in hot southern regions, almost all begonias will need protection from the intense afternoon sun to avoid leaf burn.
How often should I water my outdoor begonias?
There is no set schedule, as watering depends on your local weather and soil. The best rule is to check the soil daily; if the top inch feels dry to the touch, it is time to water. Begonias in containers typically need more frequent watering than those planted in the ground, sometimes even daily during a heatwave.
Why are the leaves on my begonia turning yellow?
Yellow leaves are most often a sign of overwatering or poor drainage. When the roots sit in water for too long, they cannot breathe, which causes the leaves to discolor. If you see yellowing, let the soil dry out a bit more between waterings and ensure your pots are draining properly.
Do I need to dig up my begonias in the winter?
In USDA Zones 9-11, begonias can often stay in the ground year-round. In colder zones (Zones 3-8), they will not survive a freeze. You can either treat them as annuals and replace them each year or dig up tuberous varieties and store them in a cool, dry place until spring.
