Table of Contents
- Introduction
- Choosing the Best Begonias for Your Baskets
- When to Start Your Begonia Corms
- Preparing the Perfect Hanging Basket
- The Sprouting Process: Which Side Is Up?
- How to Plant Begonia Corms in the Basket
- Providing the Right Light and Water
- Transitioning Baskets to the Outdoors
- Maintaining Your Display All Summer
- Summary of Success
- Conclusion
- FAQ
Introduction
There is something truly special about a hanging basket overflowing with lush, vibrant begonias. These plants are the stars of the shade garden, offering rose-like blooms and dramatic foliage that can brighten up even the quietest corner of a porch or patio. If you have ever admired a cascading display of flowers and wondered how to achieve it yourself, you are in the right place. Planting begonia corms—also known as tubers—is a rewarding way to create high-impact displays that last from midsummer right through the first frost.
At Longfield Gardens, we enjoy helping gardeners find the best ways to bring more beauty to their outdoor spaces. Growing begonias from corms is an affordable and satisfying project that even a beginner can master. For gardeners who want to explore more warm-season options, our Spring-Planted Summer-Blooming Bulbs collection is a helpful place to start. This guide will walk you through everything you need to know about selecting the right varieties, preparing your baskets, and ensuring your plants thrive. By following a few simple steps, you can enjoy a season full of spectacular, cascading color.
Choosing the Best Begonias for Your Baskets
Before you start planting, it is important to choose the right type of begonia for Hanging Begonias. While all tuberous begonias are beautiful, they have different growth habits. Some grow straight up, while others naturally trail or cascade.
Cascading vs. Upright Varieties
For hanging baskets, you generally want varieties labeled as "pendula" or "cascading." These varieties have flexible stems that gracefully arch over the sides of a container. As the plants grow, the weight of the large, heavy blooms pulls the stems downward, creating a waterfall of color.
Upright Double Begonias are stunning but are often better suited for garden beds or stationary pots. However, you can certainly mix them into a large hanging basket for a fuller, tiered look. If you use upright types, just keep in mind that they may need a bit more protection from the wind.
Selecting Quality Corms
When you receive your corms from us, you will notice they look like small, brown, dusty pucks or bowls. A healthy corm should feel firm and heavy for its size. If you see tiny pink or red buds starting to peek out from the center, that is a great sign. It means the plant is already waking up and ready to grow.
Key Takeaway: Always choose cascading or "pendula" begonia varieties for hanging baskets to achieve that classic trailing look. Look for firm, healthy corms to ensure a strong start for your plants.
When to Start Your Begonia Corms
Timing is one of the most important factors when growing begonias. These are tropical plants that love warmth and cannot tolerate even a hint of frost.
Starting Indoors for Earlier Blooms
Begonias can take a while to get going. It usually takes about 12 to 15 weeks from the time you plant the corm to the time you see the first flowers. To get the most out of your growing season, we recommend When to Plant Begonia Bulbs for a Stunning Shade Garden about 8 to 12 weeks before the last expected frost in your area.
Starting them early in a warm, indoor environment gives them a head start. By the time the weather is warm enough to move the baskets outside, your plants will already be well-established with plenty of green leaves.
Waiting for the Right Outdoor Temperature
It is tempting to move your baskets outside as soon as the sun starts shining in spring. However, begonias are very sensitive to cold soil and chilly nights. Wait until the nighttime temperatures consistently stay above 50°F before hanging your baskets outdoors. If a surprise late-season frost is predicted, be sure to bring your baskets into a garage or shed for the night, and check the Hardiness Zone Map if you are unsure about local timing.
Preparing the Perfect Hanging Basket
A successful begonia display starts with the right foundation. This includes the basket itself and the soil you put inside it.
Selecting the Right Container
Hanging baskets come in many styles, from plastic and ceramic to wire baskets lined with coco-fiber. For begonias, drainage is the most critical feature. These plants like moisture, but they will not tolerate sitting in soggy soil. Ensure your basket has several drainage holes at the bottom, and take a look at our Summer Blooming Bulbs for Containers collection for more container inspiration.
If you are using a wire basket with a coco-fiber liner, remember that these dry out much faster than plastic pots. You may need to water them more frequently once the summer heat arrives.
Choosing a Growing Mix
Always use a high-quality potting mix designed for containers. Do not use soil from your garden, as it is too heavy and does not drain well enough for begonias. Garden soil can also contain pests or diseases that might harm the tender corms.
A good potting mix will be light and fluffy. It usually contains a blend of peat moss or coco-coir, perlite, and sometimes a bit of compost. This combination holds onto the moisture the plants need while allowing excess water to flow away from the roots.
- Tip: Look for a mix that includes a slow-release fertilizer. This provides a steady stream of nutrients to your begonias as they grow.
- Drainage Check: If you pour water into the pot and it takes more than a few seconds to disappear from the surface, your mix might be too heavy.
The Sprouting Process: Which Side Is Up?
One of the most common questions we hear at Longfield Gardens is, "Which way do I plant this?" It can be a little confusing because begonia corms don't look like traditional flower bulbs.
Identifying the Top and Bottom
The easiest way to tell which side is the top is to look for the "bowl." One side of the corm is usually slightly hollow or indented, like a shallow dish. This indented side is the top. This is where the stems and leaves will emerge.
The other side is rounded or convex. This is the bottom, where the roots will grow. If you look closely at the indented top, you might see small, bumpy "eyes" or even tiny pink sprouts. Those sprouts should always face the sky.
What to Do If You Can't Tell
Sometimes a corm is so round that it is hard to tell the top from the bottom. If you are unsure, you can plant the corm on its side. The plant is smart enough to send its stems upward and its roots downward regardless of its position.
Pre-Sprouting (Optional but Helpful)
If you have the space, you can pre-sprout your corms before putting them in their final hanging baskets. Place the corms close together in a shallow tray filled with damp potting mix. Keep them in a warm spot with indirect light. Once you see a few inches of green growth, you can carefully move them into their permanent baskets. For more detail, see our Tips for Growing Tuberous Begonias.
How to Plant Begonia Corms in the Basket
Once your corms are ready and your baskets are filled with soil, it is time to plant. This process is simple, but getting the planting depth right will make a big difference in the final look of your display.
Step 1: Fill and Moisten
Fill your hanging basket with potting mix, leaving about two inches of space below the rim. This gap is important because it prevents water and soil from spilling over the edge when you water the plants later. Lightly moisten the soil so it is damp but not dripping wet.
Step 2: Position the Corms
For a standard 10-inch or 12-inch hanging basket, we recommend planting three corms. This ensures the basket looks full and lush from all sides. Space the corms evenly in a triangle pattern.
Step 3: Set the Depth
Place each corm on the surface of the soil with the hollow side facing up. Gently press it into the mix. You only want to cover the corm with about half an inch to one inch of soil. Begonias do not like to be planted too deep. For more detail, see How Deep Should Begonias Be Planted for Success?.
Step 4: Initial Watering
Water the basket gently after planting. Use a light touch so you don't wash away the soil covering the corms. From this point on, keep the soil consistently moist but never saturated.
What to do next:
- Label your baskets so you remember which varieties you planted.
- Place the baskets in a warm, bright indoor spot (about 70°F).
- Wait patiently; sprouts can take several weeks to appear.
- Check the soil every few days to ensure it hasn't dried out completely.
Providing the Right Light and Water
As your begonias begin to grow, their needs will change. Understanding their preferences for light and water is the key to a long blooming season.
The Importance of Shade
Begonias are famous for their ability to thrive in the shade. In fact, most varieties will scorch if they get too much direct, hot afternoon sun. The ideal location for a hanging basket is a spot that receives "dappled" light or morning sun and afternoon shade. For more shade-loving options, browse our Spring-Planted Bulbs for Shade collection.
A covered porch, the north side of a house, or underneath a leafy tree are all perfect locations. If the leaves of your begonia start to look brown and crispy at the edges, it is likely getting too much sun. If the plant is growing very tall and "leggy" with few flowers, it might need a little more light.
Mastering the Watering Routine
Watering hanging baskets can be tricky because they dry out much faster than plants in the ground. During the height of summer, you may need to water your begonia baskets every day.
The best way to tell if your plants need water is the "finger test." Stick your finger into the soil up to the first knuckle. If it feels dry, it is time to water. When you water, try to aim for the soil rather than the leaves. Keeping the foliage dry helps prevent fungal issues. For a deeper watering guide, see How Much Water Does a Begonia Plant Need?.
Feeding for More Flowers
Begonias are heavy feeders. Because they grow so much and produce so many large flowers in a single season, they need plenty of nutrients. If your potting mix didn't include a slow-release fertilizer, you should start a regular feeding schedule once the plants have several sets of leaves.
A balanced, water-soluble fertilizer applied every two weeks is usually sufficient. Look for a fertilizer with a slightly higher middle number (phosphorus), as this encourages flower production rather than just green leaves.
Transitioning Baskets to the Outdoors
Moving your begonias from the cozy indoors to the unpredictable outdoors requires a bit of care. This process is called "hardening off." For more basket-specific guidance, see How to Plant Begonias in Hanging Baskets.
The Hardening Off Process
About a week before you plan to hang your baskets outside for good, start bringing them out for a few hours at a time. Put them in a sheltered, shady spot for two or three hours in the afternoon, then bring them back inside.
Gradually increase the amount of time they spend outside each day. This allows the plants to get used to the movement of the wind, the changes in humidity, and the brighter light. By the end of the week, they will be tough enough to stay outside permanently.
Protecting Against Wind
Tuberous begonias have somewhat brittle stems. Because the flowers are so heavy, a strong gust of wind can sometimes snap a stem. If you live in a particularly windy area, try to hang your baskets in a protected spot, such as against a wall or in a corner of a porch.
Maintaining Your Display All Summer
Once your begonias are established and blooming, they are relatively low-maintenance. However, a little bit of grooming will keep them looking their best until autumn.
Deadheading and Cleaning
Deadheading is the practice of removing faded flowers. For begonias, this isn't strictly necessary to keep the plant blooming, but it does make the basket look much tidier. It also prevents the old, wet petals from falling onto the leaves, which can sometimes cause rot.
Simply pinch off the flower stem where it meets the main branch. While you are at it, remove any yellowing or damaged leaves to keep the plant healthy and allow for better airflow.
Managing Growth
If your cascading begonias are getting a bit too long or looking thin at the top, don't be afraid to pinch back the tips of the stems. This encourages the plant to branch out, resulting in a fuller, bushier basket.
"A little bit of regular attention goes a long way with begonias. By checking the moisture and removing old blooms once a week, you can keep your hanging baskets looking like a professional display all season long."
Summary of Success
Planting begonia corms in hanging baskets is one of the most effective ways to add elegance to your home's exterior. By choosing cascading varieties and starting them indoors, you set the stage for a spectacular show. Remember that these plants value three things above all else: warmth, consistent moisture, and protection from the harsh sun.
As you watch your corms transform from small brown pucks into lush, flowering masterpieces, you will see why begonias remain a favorite for gardeners everywhere. The process is simple, the results are stunning, and the joy they bring to a shaded porch is unmatched.
Conclusion
Creating your own hanging baskets with begonia corms is a fun and rewarding gardening project. It allows you to choose specific colors and styles that you might not find at a local garden center. By starting with high-quality corms and following these straightforward planting steps, you are well on your way to a beautiful summer display.
- Start corms indoors 8 to 12 weeks before the last frost for the best results.
- Always plant the hollow side of the corm facing up.
- Keep soil moist and provide plenty of filtered shade once moved outdoors.
We invite you to explore the many beautiful varieties available at Longfield Gardens and start your own begonia journey today. With a little patience and care, our 100% Quality Guarantee helps make every season more rewarding.
FAQ
How many begonia corms should I plant in a 12-inch hanging basket?
For a full and lush appearance, we recommend planting three corms in a 12-inch basket. Space them evenly in a triangle shape to ensure the foliage and flowers fill out the basket in all directions.
Can I leave my begonia hanging baskets in full sun?
Most tuberous begonias prefer partial to full shade and will struggle in direct, hot afternoon sun. A location with morning sun and afternoon shade is ideal, as it provides enough light for blooming without scorching the delicate leaves and flowers.
Why are my begonia corms not sprouting?
Begonia corms can be slow to wake up, sometimes taking three to four weeks to show signs of life. Ensure they are kept in a warm spot (around 70°F) and that the soil is kept moist but not soggy, as cold or overly wet soil can delay growth or cause rot.
Do I need to cover the begonia corms with soil?
Yes, you should cover the corms, but only slightly. Aim for about half an inch to an inch of potting mix over the top of the corm to protect it while still making it easy for the new sprouts to reach the surface. For more detail, see How Deep Should Begonias Be Planted for Success?.