Introduction
There is a unique kind of magic in discovering a plant that thrives in the quiet, shaded corners of a yard. Begonias are the undisputed stars of the shade, offering lush foliage and vibrant, rose-like blooms that brighten up porch containers and garden beds alike. Whether you are drawn to the shimmering, colorful leaves of foliage varieties or the massive, cascading flowers of tuberous types, these plants bring a tropical elegance to any space. At Longfield Gardens, we want to help you enjoy the simple rewards of growing these versatile beauties throughout the summer season.
This guide is designed for home gardeners who want to master the basics of begonia care, from choosing the right variety to ensuring a long season of flowers. We will cover planting techniques, watering habits, and the best ways to keep your plants healthy and vigorous. By focusing on a few core needs—such as proper light and good drainage—you can create a stunning display that lasts from early summer until the first frost.
Choosing the Right Begonia for Your Space
The first step to success is matching the right begonia to your specific garden environment. Begonias are a diverse family with thousands of species, but most home gardeners focus on a few reliable types that perform exceptionally well in North American climates.
Tuberous Begonias
These are the heavy hitters of the flower world. Tuberous begonias are famous for their large, multi-petaled blooms that look remarkably like roses or camellias. They are generally grown from tubers (thick, underground stems) and come in two main styles: upright and trailing. Upright varieties are perfect for garden borders and window boxes, while trailing types, such as the Pendula or Hanging Basket varieties, look spectacular cascading over the edges of pots.
Rex Begonias
If you prefer dramatic foliage over flowers, Rex begonias are the perfect choice. These plants are grown for their spectacular leaves, which feature swirls of silver, purple, pink, and deep burgundy. While they do produce small flowers, the real show is the metallic sheen and intricate patterns of the foliage. They are excellent as indoor houseplants or as high-contrast accents in shaded outdoor containers.
Wax Begonias (Fibrous Begonias)
These are the hardy "workhorses" often seen in mass plantings in parks or along walkways. Wax begonias have succulent-like, waxy leaves and clusters of small red, white, or pink flowers. They are more tolerant of sun and heat than their tuberous cousins, making them a great choice for areas that receive a bit more light.
Cane Begonias
Often called "Angel Wing" begonias because of the shape of their leaves, cane begonias grow on tall, bamboo-like stems. They are incredibly easy to grow and are often kept as year-round houseplants. They produce beautiful, dangling clusters of flowers and frequently have silver-spotted leaves that add interest even when the plant isn't in bloom.
Key Takeaway: Match your begonia to your goal. Choose tuberous types for big summer flowers, Rex types for stunning leaf patterns, and wax types for low-maintenance garden borders.
Getting a Head Start Indoors
One of our favorite tips for growing begonias is to start the tubers indoors before the outdoor planting season begins. Because begonias are tropical plants, they need a long growing season to reach their full potential. Starting them inside gives them a six-to-eight-week head start, resulting in larger plants and earlier flowers.
To start your begonias indoors, begin in late winter or early spring—usually March or April. Use shallow pots or trays with drainage holes and fill them with a light, high-quality potting mix.
When you look at a begonia tuber, you will notice one side is slightly indented or "hollowed out." This is the top. Place the tuber into the soil with the hollow side facing up. You don’t need to bury them deeply; simply press them into the moist soil so the tops are just barely covered or even slightly exposed.
Keep the pots in a warm spot (around 70°F) with indirect light. A kitchen counter or a spot near a bright window works well. Water very sparingly at first. The goal is to keep the soil slightly damp but never wet, as the tubers can rot if they sit in soggy soil before they have roots to drink the water.
What to Do Next
- Check your tubers for small pink or red "eyes" (buds) before planting.
- Use a spray bottle to mist the soil surface if it feels dry.
- Once sprouts appear, move the plants to a location with more light to prevent them from becoming leggy.
- Wait until the plants have at least two sets of leaves before moving them to larger pots.
Finding the Perfect Location
Right plant, right place is a rule that begonias live by. Most begonias are naturally understory plants, meaning they evolved to grow beneath the canopy of trees where the light is soft and filtered.
Light Requirements
Tuberous and Rex begonias prefer partial shade. This usually means a spot that gets four to six hours of gentle morning sun but is protected from the harsh, direct rays of the afternoon. If the leaves look scorched or have brown, crispy edges, they are likely getting too much sun. Conversely, if the plant is stretching and produces very few flowers, it probably needs a bit more light.
Soil and Drainage
"Drainage" is simply a term for how fast water leaves the soil. Begonias have fleshy stems and roots that hold a lot of moisture, which makes them very sensitive to "wet feet." If the soil stays saturated, the roots cannot breathe, and the plant may rot.
For garden beds, ensure the soil is loose and rich in organic matter. If your soil is heavy clay, consider planting begonias in raised beds or containers where you can control the soil quality. Use a high-quality potting mix that contains perlite or vermiculite to help keep the texture light and airy.
Protection from Wind
Because begonias have brittle stems and large, heavy flowers, they can be easily damaged by strong winds. If you are planting tall upright varieties, choose a sheltered spot near a fence or wall, or plan to provide small stakes for support as the plants grow.
Key Takeaway: Filtered light and fast-draining soil are the foundations of begonia success. Avoid dark corners and heavy, waterlogged dirt.
Planting Outdoors: Timing and Depth
Timing is everything when it comes to moving your begonias outside. These plants are very sensitive to cold temperatures. Even a light frost can be fatal, and a cold snap (temperatures below 50°F) can cause the plant to stop growing for several weeks.
Wait to move your begonias outdoors until the soil is warm and the danger of frost has completely passed. In most regions, this is around the same time you would plant tomatoes or peppers. Check your USDA hardiness zone before finalizing your planting schedule.
Planting Tubers Directly Outdoors
If you prefer not to start them indoors, you can plant tubers directly in the garden once the weather is warm.
- Loosen the soil to a depth of about six inches.
- Dig a shallow hole and place the tuber hollow-side up.
- Cover the tuber with about an inch of soil.
- Space the tubers 8 to 12 inches apart to allow for good air circulation.
Transplanting Potted Begonias
If you started your plants indoors, you will need to "harden them off" before they move to their permanent outdoor home. This means placing them outside in a shaded, protected spot for a few hours each day, gradually increasing their exposure to the outdoors over a week. This prevents the plants from being shocked by the change in temperature and light intensity.
Quick Success Tips
- Check your local "last frost date" before moving plants outside.
- Space plants far enough apart that their leaves won't touch when fully grown.
- Apply a light layer of mulch around the base to keep the soil moisture consistent.
Water Correctly, Not Constantly
Watering is often where gardeners feel the most uncertainty, but the "deep, then dry" method makes it simple. Begonias prefer consistent moisture, but they need their soil to dry out slightly between waterings.
The best way to tell if your begonias need water is to use your finger. Stick it about an inch into the soil. If it feels dry, it is time to water. If it feels cool and damp, wait a day or two. For more detail, see this guide to watering and caring for begonias.
When you water, try to aim the stream at the base of the plant rather than splashing the leaves. Wet foliage, especially in humid weather, can lead to fungal issues like powdery mildew. If you are growing begonias in containers, make sure the pots have drainage holes at the bottom so excess water can escape. Never let your pots sit in a saucer full of water for more than an hour.
Adjusting for Weather
During a heatwave, your begonias will use water much faster and may need a drink every day, especially if they are in hanging baskets. In cooler or rainy weather, you may go a week or more without needing to water. Watching the plant's leaves is also helpful; if they begin to look slightly limp or "matte" instead of shiny, the plant is likely thirsty.
Key Takeaway: Aim for "moist like a wrung-out sponge." Avoid the extremes of bone-dry soil or swampy mud.
Feeding Your Begonias for Maximum Blooms
Begonias are "heavy feeders," which means they use a lot of nutrients to produce those massive flowers and colorful leaves all summer long. Regular feeding ensures the plant doesn't run out of energy halfway through the season.
For flowering varieties, a balanced, water-soluble fertilizer works best. Look for a formula where the three numbers on the label (N-P-K) are roughly equal, or one where the middle number (phosphorus) is slightly higher to encourage blooming. A "bloom booster" style fertilizer is often very effective for tuberous begonias.
A Simple Feeding Schedule
- At Planting: Mix a slow-release fertilizer into the soil to provide a steady base of nutrients.
- During Growth: Once the plant has several leaves, apply a liquid fertilizer at half-strength every two weeks.
- Late Summer: Continue feeding through August to keep the flower production high.
- Autumn: Stop fertilizing as the weather cools and the plant begins to prepare for dormancy.
For foliage types like Rex begonias, you can use a fertilizer with a slightly higher first number (nitrogen), which supports healthy leaf growth. Always follow the instructions on the fertilizer label to avoid over-feeding, which can lead to lush leaves but very few flowers.
Pruning and Maintenance
Begonias are relatively self-sufficient, but a little bit of grooming goes a long way in keeping them looking their best.
Deadheading
"Deadheading" is the process of removing spent or faded flowers. On many begonias, the old flowers will drop off on their own, but removing them manually helps the plant look tidy. More importantly, it prevents the plant from putting energy into producing seeds, redirecting that energy back into creating more blooms.
Pinching
If your begonias are looking thin or "leggy," you can "pinch" them to encourage bushier growth. Simply use your thumb and forefinger to snip off the very tip of a growing stem. This signals the plant to grow two new stems from the leaf joints below, resulting in a fuller, more compact plant.
Staking
Large-flowered upright begonias can sometimes become "top-heavy." To prevent the stems from snapping, you can insert a thin bamboo stake into the soil near the base of the plant and gently secure the main stem to the stake with a piece of garden twine or a soft clip. Be careful not to pierce the tuber when inserting the stake.
Next Steps for Maintenance
- Remove any yellow or spotted leaves as soon as you see them.
- Keep the area around the base of the plant free of fallen petals to prevent mold.
- Check for pests like aphids or snails, which occasionally enjoy begonia leaves.
Growing Begonias in Containers
Begonias are perhaps the most popular choice for shade containers, and for good reason. Their roots are relatively shallow, so they don't need massive pots to thrive. A standard 8-to-12-inch pot is usually plenty for a single tuberous begonia.
When planting in containers, use a high-quality potting soil rather than garden soil. Garden soil is too heavy and won't provide the air space begonia roots need. For more detailed instructions, read this guide to planting begonias in containers.
To create a professional-looking "mixed" container, try the "Thriller, Filler, Spiller" method:
- Thriller: Use a tall Cane or Upright Tuberous begonia as the center focal point.
- Filler: Surround the center with lower-growing foliage plants like Rex begonias or Coleus.
- Spiller: Add a trailing begonia or Creeping Jenny near the edges to cascade over the side.
Containers dry out much faster than the ground, so keep a closer eye on the moisture levels. In the peak of summer, a hanging basket might need water once or even twice a day if it is particularly breezy.
Key Takeaway: Containers give you total control over soil and drainage. They are the easiest way for a beginner to get great results with begonias.
Overwintering for Next Year
One of the best things about begonias is that they can be enjoyed year after year. While many gardeners treat them as annuals, it is quite simple to save the tubers for the following spring. This begonia overwintering guide provides additional storage advice.
For Tuberous Begonias
As the weather cools in the fall, the plant will naturally start to turn yellow and die back. This is the plant's way of sending energy down into the tuber for storage.
- Stop Watering: Once the leaves begin to yellow, stop watering to let the soil dry out.
- Lift the Tubers: After the first light frost kills the top growth, carefully dig up the tubers.
- Clean and Dry: Gently shake off the excess soil and cut the stems back to about an inch. Let the tubers sit in a dry, shady spot for a few days to "cure."
- Store: Place the tubers in a cardboard box or paper bag filled with peat moss, sawdust, or shredded paper. Store them in a cool, dark, frost-free place (like a basement or garage) until spring.
For Rex and Cane Begonias
These varieties can simply be moved indoors to live as houseplants during the winter. They prefer a bright spot with high humidity. You might notice they grow more slowly during the winter months, which is normal. Reduce your watering and stop fertilizing until the days begin to lengthen in the spring.
Troubleshooting Common Issues
If your begonias aren't looking quite right, the fix is usually a simple adjustment of one of the basics.
Why Are the Leaves Turning Yellow?
Yellow leaves are most often a sign of overwatering. If the soil is soggy, the roots can't function. Let the soil dry out for a few days and ensure your pot has good drainage. Occasionally, yellowing can be a sign of a nutrient deficiency, which a light dose of liquid fertilizer can fix.
Why Are the Flower Buds Falling Off?
Bud drop is usually caused by extreme temperature changes or inconsistent watering. If the plant gets too dry and then suddenly gets a lot of water, it may drop its buds in stress. Keeping the moisture levels steady is the best way to prevent this.
What Is This White Powder on the Leaves?
This is likely powdery mildew, a common fungal issue. It usually happens when there is poor air circulation or when the leaves stay wet for too long. To fix it, move the plant to a spot with better airflow and be careful to water only the soil, not the foliage.
Why Are the Leaf Edges Brown and Crispy?
This is typically a sign of low humidity or too much direct sun. If the plant is in a very sunny spot, move it into more shade. If it is an indoor plant, try placing it on a tray of pebbles filled with water to increase the local humidity.
Key Takeaway: Most begonia problems are caused by too much water or too much sun. Adjust those two factors first before trying more complex fixes.
Conclusion
Growing begonias is a rewarding way to add vibrant color and lush textures to the shaded areas of your garden. By selecting the right variety for your goals and providing well-draining soil and filtered light, you can enjoy these tropical beauties all season long. Remember that success doesn't require a green thumb—it simply requires paying attention to the plant's basic needs.
At Longfield Gardens, we believe that every gardener can find success with these stunning plants. Whether you are starting your first tuberous begonia indoors this spring or creating a complex container display on your patio, the process is an enjoyable journey. With a little bit of patience and consistent care, your begonias will become the highlight of your summer garden.
- Start tubers indoors 6–8 weeks before the last frost for more blooms.
- Always ensure pots and garden beds have excellent drainage.
- Water only when the top inch of soil feels dry.
- Fertilize regularly to support heavy blooming and colorful foliage.
"Gardening is a practice of observation. By watching how your begonias respond to light and water, you become the expert in your own unique backyard environment."
FAQ
Can begonias grow in full sun?
Most begonias, especially Tuberous and Rex varieties, prefer partial shade and will scorch in direct afternoon sun. However, Wax begonias are much more tolerant of sunlight and can thrive in full sun if they are given enough water and the climate isn't excessively hot.
How deep should I plant begonia tubers?
Begonia tubers should be planted quite shallowly. Indoors, they should be pressed into the soil so the tops are just barely covered. Outdoors, cover them with no more than one inch of soil. Always ensure the "hollow" or indented side of the tuber is facing up. For additional guidance, see this article on planting begonia tubers.
Why are my begonia stems so brittle and breaking?
Begonias naturally have fleshy, succulent-like stems that are quite fragile. This is often caused by the weight of large flowers or exposure to strong winds. You can help prevent breakage by choosing a sheltered planting site and using small stakes to support tall upright varieties.
Do begonias need a lot of fertilizer?
Yes, begonias are considered heavy feeders. Because they produce many large flowers or intense foliage over a short season, they benefit from a balanced, water-soluble fertilizer every two weeks. This keeps the plant energized and prevents it from fading late in the summer.
