Table of Contents
- Introduction
- Choosing the Right Time to Plant
- Selecting the Perfect Location
- Understanding the Begonia Tuber
- How to Plant Begonia Tubers Outside
- Watering and Feeding for Success
- Maintenance and Summer Care
- Popular Begonia Varieties to Try
- Dealing with Challenges
- End of Season Care
- Conclusion
- FAQ
Introduction
Tuberous begonias are some of the most rewarding plants you can add to your garden. They offer lush foliage and spectacular, rose-like flowers in a palette of colors that can brighten even the dimmest corners of your yard. Whether you are looking for begonias for a hanging basket or upright varieties for a shaded border, these plants provide elegance with surprisingly little effort.
At Longfield Gardens, we want to help you enjoy the beauty of these tropical favorites in your own outdoor space. This guide covers everything you need to know about how to plant begonia tubers outside, from choosing the right spot to ensuring they thrive all summer long. These instructions are designed for gardeners of all experience levels who want professional results with a simple approach.
With a few basic steps, you can transform your patio or garden beds into a vibrant floral retreat. Planting begonia tubers outside is a straightforward process that rewards your patience with months of continuous color.
Choosing the Right Time to Plant
Begonias are tropical plants by nature. They love warmth and are very sensitive to cold temperatures. This means timing is the most important factor when you are moving them into the garden.
Wait for Warm Soil
You should only plant begonia tubers outside when the soil has warmed up and all danger of frost has passed. A good rule of thumb is to wait until nighttime temperatures consistently stay above 50°F. If you’re unsure about your region, the hardiness zone map can help. If the ground is still cold and soggy from spring rains, the tubers may sit dormant or struggle to start.
Watching the Weather
In most regions, late May or early June is the ideal window for outdoor planting. If you live in a colder climate, you might feel tempted to plant early. It is better to wait an extra week for stable weather than to risk a late-season frost. If a surprise cold snap is predicted after you have planted, you can temporarily cover your begonias with a light cloth or bring containers into a garage. Our shipping information page can also help you plan by zone.
Hardening Off Indoor Starts
Many gardeners choose to start their tubers indoors in late winter to get a head start on the blooming season. If you have done this, your plants need a transition period before they live outside full-time. This process is called "hardening off."
Start by placing your begonias in a sheltered, shady spot outside for an hour or two during the day. Gradually increase their time outdoors over the course of a week. This helps the leaves adjust to the wind and shifting light levels. Once they have spent a few full days outside and the nights are warm, they are ready for their permanent home.
Selecting the Perfect Location
Success with begonias starts with finding a spot that mimics their natural forest-floor habitat. They enjoy light and humidity but need protection from the harsh elements.
Light Requirements
Begonias are famous for their ability to bloom in the shade. However, "shade" does not mean total darkness. They perform best in filtered light or dappled shade, such as under a tree canopy or on a covered porch. For more shade-loving ideas, see Summer Bulbs for Shady Gardens.
Most varieties prefer morning sun and afternoon shade. The morning sun is cool and helps the plant produce energy. The hot, direct light of the afternoon can scorch the tender leaves and cause the flowers to wilt. If you are gardening in a very hot climate, provide even more shade to keep the plants cool.
Soil and Drainage
The way water moves through your soil is a major factor in begonia health. These plants need "well-drained" soil. This means water should soak in easily and not leave puddles behind. For step-by-step help, read How to Prepare Soil for Planting.
If your garden soil is heavy clay, it can trap too much moisture around the tuber. You can improve drainage by mixing in organic matter like compost or finely shredded bark. For container gardening, always use a high-quality potting mix rather than garden soil. Make sure every pot has at least one drainage hole at the bottom.
Protection from Wind
Begonias have succulent, brittle stems that can snap in heavy winds. Choose a location that is naturally sheltered by a fence, a wall, or other sturdy plants. This protection helps the plants grow tall and full without the risk of storm damage.
What to do next: Site Preparation
- Identify a spot with dappled shade or morning sun.
- Check the soil drainage by watching how fast water disappears after a rain.
- Clear any weeds or debris from the planting area.
- Gather compost or potting mix to amend the site if needed.
Understanding the Begonia Tuber
When you first look at a begonia tuber, it might not look like much. It is usually brown, hairy, and shaped like a small bowl or a thick coin. Understanding which side is which is the key to successful planting.
Identifying the Top and Bottom
One side of the tuber is "concave," meaning it has a hollow or indented center like a dish. This is the top. This hollow area contains the "eyes" or growth points where the stems will emerge.
The other side is "convex," meaning it is rounded or domed. This is the bottom. The roots will grow from the sides and the bottom of this rounded area.
Tuber Size and Quality
We provide premium, top-size tubers because larger tubers hold more stored energy. This extra energy allows the plant to produce more stems and a higher volume of flowers throughout the season. When you handle your tubers, they should feel firm and heavy for their size. If you see small pink or green nubs in the hollow center, those are the sprouts starting to wake up.
Key Takeaway Always plant begonia tubers with the hollow, bowl-shaped side facing up. This ensures the stems can grow directly toward the light while the roots grow down into the soil.
How to Plant Begonia Tubers Outside
Once the weather is warm and you have selected your site, it is time to plant. The process is slightly different depending on whether you are planting in the ground or in containers.
Planting in Garden Beds
- Prepare the Soil: Loosen the soil to a depth of about 6 inches. Mix in some compost to provide a light, nutrient-rich environment.
- Dig a Shallow Hole: Begonias do not like to be buried deep. Create a space just deep enough for the tuber.
- Position the Tuber: Place the tuber in the hole with the hollow side facing up.
- Cover Lightly: Cover the tuber with only about 1/2 inch to 1 inch of soil. If you bury them too deeply, they may rot before they can reach the surface.
- Space Correctly: Space your begonias about 10 to 12 inches apart. This gives the foliage plenty of room to spread out and ensures good air circulation between plants.
Planting in Containers and Hanging Baskets
- Choose the Right Pot: Ensure the container has drainage holes. A 12-inch pot is usually perfect for two or three tubers.
- Fill with Potting Mix: Use a fresh, lightweight potting mix. Avoid using heavy garden soil in pots.
- Set the Tubers: Place the tubers on the surface of the soil, hollow side up.
- Cover and Water: Cover with about an inch of mix and water lightly to settle the soil.
Orientation and Spacing Tips
If you cannot tell which side is the top, you can plant the tuber on its side. The plant will naturally direct its stems upward and its roots downward. Proper spacing is essential because crowded plants are more prone to mildew. Give them enough room to "breathe" so the air can move through the leaves.
What to do next: Planting Day
- Loosen the soil and add compost for nutrients.
- Place tubers 10-12 inches apart.
- Ensure the hollow side faces the sky.
- Cover with no more than 1 inch of soil.
- Water gently to settle the soil around the tuber.
Watering and Feeding for Success
Once your begonias are in the ground, they need consistent care to produce those iconic blooms. They are not difficult to maintain, but they do appreciate a routine.
The Right Way to Water
The goal is to keep the soil "moist but not soggy." Begonia tubers act like sponges and can rot if they sit in standing water for too long.
- Check the Soil: Stick your finger about an inch into the soil. If it feels dry, it is time to water. If it still feels damp, wait a day.
- Water the Base: Always try to water the soil at the base of the plant rather than splashing the leaves. Wet leaves in the shade can lead to fungal issues like powdery mildew.
- Morning is Best: Watering in the morning gives the plant time to hydrate before the warmth of the day and allows any accidental moisture on the leaves to dry.
Fertilizer for Continuous Blooms
Begonias are heavy feeders. Because they bloom continuously from summer until the first frost, they need a steady supply of nutrients.
We recommend using a balanced, water-soluble fertilizer. A "balanced" fertilizer has equal parts nitrogen, phosphorus, and potassium (look for numbers like 10-10-10 or 20-20-20 on the label). You can apply this every two weeks according to the package instructions. This regular feeding keeps the foliage green and the flower production high.
Adjusting for Weather
During a heatwave, your begonias may need water more frequently, especially if they are in hanging baskets. Baskets dry out much faster than garden beds because they are exposed to air on all sides. Check your containers daily during the peak of summer.
Maintenance and Summer Care
A little bit of grooming goes a long way in keeping your begonias looking their best. These simple tasks only take a few minutes a week.
Deadheading
"Deadheading" is the process of removing faded or spent flowers. When a bloom starts to wilt or turn brown, simply pinch it off at the stem. This prevents the plant from putting energy into seed production and encourages it to grow more flowers instead. It also keeps the plant looking tidy and fresh. For more care details, see Tips for Growing Tuberous Begonias.
Supporting Tall Varieties
Some upright begonias, like the Double or Roseform varieties, can grow quite tall and become top-heavy with large blooms. If your plants start to lean, you can use a small bamboo stake to provide support. Gently tie the main stem to the stake using soft garden twine or a strip of fabric. Be careful not to tie it too tightly, as the stems are soft and can be easily bruised.
Grooming the Foliage
If you notice any yellowing or damaged leaves, you can clip them off with clean scissors. This improves the appearance of the plant and helps with airflow. Keeping the area around the base of the plant clean of fallen petals and leaves also helps prevent mold and pests from moving in.
Popular Begonia Varieties to Try
At Longfield Gardens, we offer a wide selection of begonia types to suit different garden styles. Choosing the right variety for your specific spot will help you get the look you want.
Upright Begonias
These varieties grow vertically and are perfect for garden borders or large patio pots.
- Upright Double Begonias: These produce massive, multi-petaled blooms that look like roses or camellias.
- Double Begonias: These produce massive, multi-petaled blooms that look like roses or camellias. Begonia Upright Double Roseform Pink is a classic example.
- Fimbriata Begonias: These unique flowers have fringed, ruffled edges that add a lot of texture to the garden.
- Picotee Begonias: These have petals with a contrasting color on the edges, creating a beautiful bi-color effect. Begonia Upright Double Picotee White is a classic example.
Trailing and Hanging Begonias
If you want flowers that spill over the edges of containers, these are the best choice.
- Hanging Begonias: These are specifically bred for hanging baskets. Begonia Hanging Golden Balcony puts on a dramatic display of color.
- Scentiment Begonias: These varieties offer a rare trait in the begonia world—a lovely, light fragrance. They work beautifully in baskets near a seating area where you can enjoy the scent.
Multiflora Begonias
If you prefer a high volume of flowers over size, multiflora types are excellent. Begonia Non Stop Mix is a strong choice because it produces dozens of smaller blooms on compact plants, making it ideal for window boxes or the front of a flower bed.
Dealing with Challenges
Gardening always involves a bit of learning, but most begonia issues are easy to solve by adjusting your care routine.
Lack of Blooms
If your plant has plenty of green leaves but no flowers, it might need more light or more food. Try moving the container to a slightly brighter spot (still avoiding direct afternoon sun) and ensure you are fertilizing every two weeks. Sometimes, a high-nitrogen fertilizer can cause too much leaf growth at the expense of flowers; switching to a balanced formula usually fixes this.
Dropping Buds
If you notice flower buds falling off before they open, the plant might be stressed by heat or inconsistent watering. Ensure the soil is staying evenly moist. In very high temperatures, try to move containers to a cooler, shadier location until the heatwave passes.
Powdery Mildew
This looks like a light dusting of white flour on the leaves. It usually happens when the air is stagnant or the leaves stay wet. To prevent this, space your plants at least 10 inches apart and always water at the soil level. If you see it appearing, remove the affected leaves and improve the airflow around the plant.
End of Season Care
In most parts of the United States, begonia tubers will not survive the winter in the ground. However, you can save the tubers and replant them next year.
Lifting the Tubers
When the first light frost hits, the foliage will turn black and die back. This is your signal to "lift" the tubers.
- Dig them up: Carefully dig around the tubers, being sure not to nick them with your shovel.
- Clean them off: Cut the stems back to about an inch long and gently brush off any loose soil.
- Dry them out: Place the tubers in a warm, dry place for a few days until they are completely dry to the touch.
Storing for Winter
Once dry, place the tubers in a paper bag or a box filled with peat moss or sawdust. Store them in a cool, dark, and dry place that stays between 40°F and 50°F (like a basement or crawl space). Check on them once or twice during the winter to make sure they aren't shriveling or rotting. Next spring, when the weather warms, you can bring them out and start the process all over again.
Conclusion
Planting begonia tubers outside is a simple way to bring professional-level beauty to the shady parts of your landscape. By choosing a well-drained spot with filtered light and waiting for the warm weather of late spring, you set the stage for a spectacular show. These plants are versatile, colorful, and incredibly rewarding for any gardener.
We are proud to provide high-quality tubers and practical advice to help your garden thrive, and we stand behind them with our 100% guarantee.
- Wait for consistent nighttime temperatures above 50°F.
- Plant in well-drained soil with the hollow side facing up.
- Maintain even moisture and feed every two weeks.
- Enjoy a continuous display of blooms until the first frost.
Ready to get started? Browse our selection of premium begonia tubers at Longfield Gardens and find the perfect colors for your shade garden today.
FAQ
Which side of the begonia tuber should face up?
The hollow or indented side of the begonia tuber should always face upward when planting. This "bowl" shape contains the growth points where the stems will emerge. The rounded, smooth side should be placed against the soil so the roots can grow downward.
How deep should I plant begonia tubers outside?
Begonia tubers should be planted quite shallowly. Dig a small hole and cover the tuber with only about 1/2 inch to 1 inch of soil. If they are buried too deep, the sprouts may struggle to reach the surface, and the tuber could potentially rot in the cool, damp soil.
Do begonias need full shade?
While begonias are famous for shade tolerance, they actually prefer dappled or filtered sunlight. They do best with gentle morning sun and protection from the intense heat of the afternoon. In total, deep shade, they may produce fewer flowers and longer, "leggy" stems as they stretch toward the light.
Can I plant begonia tubers directly in the ground?
Yes, you can plant begonia tubers directly in your garden beds once the soil is warm and the risk of frost is completely gone. When to Plant Begonias Outside for the Best Blooms explains the timing in more detail. However, because they take several weeks to sprout and grow, many gardeners prefer to start them in pots indoors a few weeks early to enjoy a longer blooming season outdoors.