Introduction
Imagine walking onto your porch or into your garden and being greeted by a lush wall of vibrant, rose-like blooms and waxy, deep-green leaves. Begonias are one of the most rewarding plants for home gardeners because they offer nonstop color from early summer right through the first frost. Whether you are tucking tuberous begonias into a hanging basket or lining a shaded walkway with wax begonias, these plants are reliable performers that brighten up any corner of the yard.
At Longfield Gardens, we want to help you achieve that full, professional look in your own garden beds and containers. One of the most common questions we receive from home gardeners is exactly how much room these plants need to thrive. Getting the spacing right is a simple step that ensures your plants have enough air to breathe and enough nutrients to produce those spectacular flowers all season long.
In this guide, we will cover everything you need to know about spacing different types of begonias in various garden settings. For a broader look at the plant, see our All About Begonias guide. This information is designed for anyone who wants to take the guesswork out of planting and enjoy a more beautiful outdoor space. By the end of this article, you will feel confident choosing the right distance for your specific varieties to ensure a healthy, crowded look without overcrowding the plants.
Why Spacing Matters for Begonias
When you first bring home your begonias or receive your tubers in the mail, they look small. It can be tempting to plant them very close together to get an instant "carpet" of color. However, giving each plant its own designated space is one of the most important things you can do for its health.
Plants need space for three primary reasons: airflow, nutrients, and light. When begonias are too crowded, air cannot move freely between the leaves. This creates a humid environment where moisture stays trapped on the foliage. In many climates, this leads to a common issue called powdery mildew, which looks like a white dust on the leaves. Proper spacing is the easiest way to prevent this and keep your foliage looking pristine.
Furthermore, each plant has a root system that needs to "eat." If roots are fighting for the same small pocket of soil, none of the plants will reach their full potential. By following a few simple rules for how close to plant begonias, you ensure each one has access to the water and nutrients it needs.
Key Takeaway Proper spacing prevents disease and ensures every plant has the resources it needs to produce large, healthy blooms all summer.
Spacing Based on Begonia Varieties
Not all begonias are the same size, so "one size fits all" spacing doesn't work. The variety you choose will dictate how much room you should leave between them. We focus on the most popular types for home gardens to help you plan your layout. If you are still deciding where begonias fit best, our Where Is the Best Place to Plant Begonias? guide can help you match the plant to the right spot.
Tuberous Begonias
Tuberous begonias are famous for their massive, ruffled flowers that can look like roses or camellias. Varieties like the "Nonstop" series or "Picotee" are favorites for their upright growth habit. These typically grow about 10 to 12 inches tall and wide.
For these varieties, we recommend planting the tubers 10 to 12 inches apart. This measurement is taken from the center of one plant to the center of the next. This distance allows the plants to grow into each other slightly by mid-summer, creating a seamless look while still allowing air to circulate around the base of the stems.
Trailing or Pendula Begonias
If you are planting trailing begonias, such as the "Illumination" or "Cascade" series, you might think they need more room because they "spill" over the sides of containers. In a garden bed, these should still be spaced about 10 to 12 inches apart. While they do spread, they don't usually grow as tall as upright varieties, and their stems are more flexible.
Wax Begonias
Wax begonias are the workhorses of the shade garden. They are often used as bedding plants to create borders or large blocks of color. Because they are generally more compact and vigorous, you have a bit more flexibility with spacing.
- For a dense border: Plant wax begonias 6 to 8 inches apart. This creates a solid line of color quickly.
- For general garden filling: Plant them 10 to 12 inches apart. They will eventually fill the gaps, but it will take a few weeks longer than the closer spacing.
Rex and Foliage Begonias
Rex begonias are grown primarily for their stunning, colorful leaves rather than their flowers. They tend to have a mounded growth habit. To appreciate the unique patterns on each leaf, it is best to give them a little extra breathing room. Spacing them 12 inches apart ensures that the beautiful foliage of one plant doesn't completely overlap and hide the next.
Spacing in Containers vs. Garden Beds
The rules change slightly depending on whether you are planting directly in the ground or using a pot or hanging basket. Containers offer a more controlled environment, and we often want them to look "finished" the moment we plant them.
In the Landscape
In a garden bed, the soil is an open system. Roots can spread out much further, but there is also more competition from weeds. When planting in the landscape, stick to the 10 to 12-inch rule. This leaves enough room for you to get a small trowel between the plants to pull weeds or add mulch without damaging the brittle begonia stems.
In Pots and Hanging Baskets
In a container, we usually want a "full" look immediately. Because you are likely using high-quality potting soil and can water more easily, you can plant begonias a bit closer together.
- 10-inch pot: Use 1 to 2 tuberous begonias.
- 12-inch pot: Use 3 tuberous begonias.
- 12-inch hanging basket: Use 3 to 4 trailing begonias for a lush, overflowing look.
When planting in containers, you aren't measuring from center-to-center as strictly. Instead, space them evenly around the pot, leaving about 2 to 3 inches between the tuber and the edge of the container.
What to Do Next: Planning Your Space
- Measure the square footage of your planting area or the diameter of your pots.
- Check the variety on your Longfield Gardens order to confirm its mature width.
- Sketch a simple "X" pattern on the soil to mark where each tuber or plant will go before you start digging.
- Keep a 10-inch piece of a wooden dowel or a ruler handy to ensure consistent spacing as you work.
The Relationship Between Depth and Spacing
While "how close" is about horizontal distance, "how deep" is the vertical part of the equation. Getting both right is the secret to a successful begonia garden. If you plant them at the correct distance but too deep, they may rot before they ever sprout.
Tuberous begonias should be planted quite shallowly. The tuber has a "hollow" or indented side and a rounded side. The indented side is the top, where the sprouts will emerge. You should tuck the tuber into the soil so that the top is barely covered—usually only about 1/2 inch to 1 inch of soil should be over the top of the tuber.
When you get the depth and spacing right, the young sprouts have an easy path to the surface and plenty of room to expand once they get there.
Key Takeaway Planting tubers too deep can cause them to rot. Aim for just 1/2 inch of soil cover and maintain 10-12 inches between plants.
Right Plant, Right Place
Even the most perfect spacing won't help if the begonias are in the wrong spot. To get the most out of your plants, match their needs to your garden's conditions. For a quick comparison of light preferences, you may also want to read Are Begonias a Shade Plant?.
Light Requirements
Most begonias thrive in partial shade. This usually means a spot that gets morning sun and afternoon shade, or "dappled" light under a tree. If you plant them in a spot with too much direct, hot afternoon sun, the leaves may scorch or turn brown at the edges. Conversely, if the shade is too deep, the plants will become "leggy"—meaning they grow long, thin stems as they stretch toward the light. Leggy plants lose their nice mounded shape and can look sparse, even if your spacing was correct.
Soil and Drainage
Begonias need "well-drained" soil. This simply means soil that allows water to move through it easily. They do not like to sit in soggy mud. If you have heavy clay soil that stays wet for a long time after it rains, the tubers can rot.
To improve drainage in a garden bed, you can mix in some organic matter like compost or shredded bark. In containers, always use a high-quality potting mix (not garden soil) and ensure the pot has at least one drainage hole at the bottom.
Timing and Temperature
Begonias are tropical plants by nature. They love warmth and cannot handle frost. This is one area where "timing beats tricks." If you plant your begonias outside too early, when the ground is still cold and damp, they will sit dormant or, worse, begin to decay.
Wait until the danger of frost has passed and the soil has warmed up to about 60°F. In most parts of the US, this is late May or early June. If you want a head start, you can start your begonias indoors in pots about 8 weeks before the last frost. By the time the weather is warm enough to move them outside, you will already have established plants ready to go. For shipping timing and zone-based delivery windows, see our Shipping Information.
A Note on USDA Zones
Begonias are typically grown as annuals in most of the United States (Zones 3-8). However, they are hardy perennials in Zones 9-11. If you live in a colder climate, you can dig up the tubers in the fall after the foliage dies back and store them in a cool, dry place to replant the following spring.
Watering Correctly, Not Constantly
Once your begonias are spaced and planted, the way you water them will determine how well they fill that space. The goal is to keep the soil "evenly moist." This means it should feel like a wrung-out sponge—damp but not dripping.
A common mistake is to water a little bit every single day. Instead, try the "deep, then dry" method. Water the plants thoroughly until the water reaches the root zone, then wait until the top inch of soil feels dry to the touch before watering again. This encourages the roots to grow deeper into the soil, making the plant stronger and more resilient to heat.
When watering, try to aim the water at the base of the plant rather than splashing it over the leaves. Keeping the foliage dry is another great way to prevent powdery mildew and other fungal issues.
Simple Troubleshooting for Spacing Issues
Sometimes, despite our best efforts, things don't look quite right. Here is how to handle the two most common spacing-related issues.
The "Too Sparse" Look
If your begonias are planted 12 inches apart and it is mid-July but you still see a lot of bare soil, don't worry. This usually happens if the soil is poor or the plants aren't getting enough nutrients. Instead of digging them up and moving them closer together—which can damage the roots—try giving them a boost with a balanced, water-soluble fertilizer. Follow the instructions on the label and apply it every two weeks. This will encourage the plants to grow wider and fill in those gaps.
The "Too Crowded" Look
If your plants are overlapping so much that the bottom leaves are turning yellow and falling off, they might be too close. This is common if you planted a more vigorous variety than expected. To fix this, you can gently "pinch back" the stems. Use your fingers or a clean pair of snips to remove the very tips of the growing stems. This encourages the plant to grow more compactly rather than getting longer and more tangled with its neighbors. It also improves airflow.
What to Do Next: Mid-Season Care
- Check for yellowing leaves at the base of the plant and remove them to improve airflow.
- Feel the soil before watering; if it’s still wet, wait another day.
- If plants look leggy, pinch back the tips to encourage a bushier habit.
- Enjoy the blooms! Begonias are "self-cleaning," meaning you don't have to remove dead flowers to keep them blooming.
Companion Planting and Spacing
Begonias look even better when paired with other shade-loving plants. When mixing different species, you still need to respect the spacing requirements for each.
For example, if you are planting begonias with Caladiums or Coleus, remember that Coleus can grow quite large and may overshadow smaller wax begonias. A good rule of thumb is to place the taller plants (like Coleus) in the back and the mounded begonias in the front. Leave 12 inches of space between a begonia and a larger companion plant to ensure the begonia doesn't get "bullied" out of its light and nutrients.
Common companions for begonias include:
- Fuchsias: Great for hanging baskets with trailing begonias.
- Ferns: Provide a soft, green texture that makes begonia colors pop.
- Lobelia: A beautiful "spiller" for the edges of pots.
- Heuchera (Coral Bells): Offers colorful foliage that complements begonia blooms.
Growing Begonias for the Long Term
One of the best things about tuberous begonias is that they can stay with you for years. Unlike many other annuals that die completely at the end of the season, begonia tubers can be "overwintered."
As the weather cools in autumn and the days get shorter, your begonias will naturally start to turn yellow. This is the plant's way of sending all its energy back down into the tuber for storage. At this point, stop watering and let the foliage die back completely. Once the stems fall off easily, you can dig up the tubers, shake off the soil, and store them in a cool, dry place (like a basement or garage) in a box of peat moss or sawdust.
By following the simple rules of spacing and care each year, those tubers will grow larger and more productive every season. It is a rewarding cycle that makes gardening feel like a long-term friendship with your plants.
Conclusion
Getting the spacing right is one of the easiest ways to ensure your begonias look spectacular all summer long. Whether you are aiming for a dense border of wax begonias at 6 inches apart or a stunning display of upright tuberous begonias at 12 inches, remember that a little room to breathe goes a long way. Proper spacing leads to better airflow, fewer diseases, and bigger, brighter flowers.
We at Longfield Gardens are here to help you succeed. Gardening should be a relaxing and joyful part of your life, and by getting these few basics right—the right plant in the right place with the right spacing—you are setting yourself up for a beautiful result. If you want to explore more options, browse our Begonia Flower Bulbs for Sale collection.
- Choose your variety: Know if it is upright, trailing, or a foliage type.
- Measure carefully: Use a 10 to 12-inch spacing as your standard for most types.
- Plant shallow: Keep tubers just 1/2 inch below the soil surface.
- Watch the weather: Only move plants outside once the soil and air are consistently warm.
"The secret to a lush garden isn't just about how many plants you have, but how much room you give each one to shine."
If you are ready to start your own shade garden masterpiece, browse our selection of premium begonia tubers and find the perfect colors for your home today.
FAQ
How far apart should I plant begonias in a window box?
In a window box, you generally want a very full look, so you can space tuberous or trailing begonias about 6 to 8 inches apart. This allows them to fill the space quickly and cascade over the edges. Ensure the window box has good drainage, as the closer spacing means the soil will stay moist longer.
Can I plant wax begonias closer than 6 inches for an instant border?
While you can plant them as close as 4 inches for an immediate effect, we don't recommend it for the long term. Overcrowded plants will struggle with airflow and may develop fungal issues or stop blooming as the roots compete for space. Sticking to 6 inches will still give you a full border within just a couple of weeks.
Does spacing change if I am planting begonias in full sun?
If you are using sun-tolerant varieties, spacing remains the same (10 to 12 inches). However, plants in the sun will dry out much faster than those in the shade. You may need to water more frequently to help those plants fill their designated space, especially during the hottest weeks of summer.
What happens if I plant begonia tubers too close together?
If tubers are too close, the plants will grow into each other very quickly, creating a dense thicket of foliage. This significantly increases the risk of powdery mildew because air cannot circulate. You might also find that the flowers are smaller because the plants are competing for the same nutrients in the soil.
