Table of Contents
- Introduction
- Choosing the Best Varieties for Your Garden Beds
- Finding the Perfect Location
- When to Plant Begonias in the Ground
- Preparing the Soil for Planting
- Step-by-Step Guide to Planting Tuberous Begonias
- Planting Wax Begonias and Started Plants
- Water Correctly, Not Constantly
- Feeding for Continuous Blooms
- Maintenance and Grooming
- What to Do at the End of the Season
- Common Myths About Planting Begonias
- Safety and Pets
- FAQ
- Conclusion
Introduction
Begonias are a favorite for adding vibrant, tropical color to the shadier corners of your landscape. With their lush foliage and brilliant blooms, these plants can transform a quiet garden bed into a stunning focal point. Whether you are looking for the massive, ruffled petals of tuberous begonias or the steady, reliable carpet of color provided by wax begonias, learning how to plant begonias in the ground is an easy way to elevate your outdoor space.
At Longfield Gardens, we believe that every gardener can find success with these versatile plants. We enjoy watching these tropical beauties flourish from midsummer all the way until the first frost. This guide is designed for home gardeners who want clear, practical steps for taking begonia tubers or starts and getting them established in the garden.
By focusing on a few simple requirements like soil temperature and drainage, you can enjoy a season full of flowers. We will cover everything from selecting the right spot to the specific planting depths that ensure your begonias thrive. Our goal is to make your gardening experience rewarding and straightforward.
Choosing the Best Varieties for Your Garden Beds
When you decide to plant begonias in the ground, the first step is selecting the type that fits your vision. If you want high-impact, large flowers, Upright Double Begonias are the way to go. Most gardeners choose between tuberous begonias and wax begonias for landscape use. While both offer beautiful results, they have slightly different growth habits and visual appeals.
Tuberous begonias are the "showstoppers" of the group. They grow from a dormant tuber and produce large, often double-flowered blooms that can resemble roses or camellias. Varieties like the "Dinnerplate" begonias offer massive blossoms that demand attention. These are ideal for the front of a shady border where you can appreciate the intricate details of the flowers.
Wax begonias, often called bedding begonias, are more compact and have a fibrous root system. They are famous for their waxy, succulent-like leaves and constant clusters of small flowers in shades of red, white, and pink. These are excellent for mass plantings or creating colorful edges along a garden path. Some varieties, like the Begonia Double Maxima Switzerland, offer dark, bronze foliage that creates a beautiful contrast against bright red flowers.
Selecting the right variety depends on your specific garden goals. If you want high-impact, large flowers, tuberous varieties are the way to go. If you want a low-maintenance carpet of color that stays uniform all season, wax begonias are a reliable choice. Both types share many of the same planting requirements, making them easy to integrate into a single garden plan.
Finding the Perfect Location
Success with begonias starts with "right plant, right place." Because begonias are tropical in origin, they have specific preferences for light, wind, and moisture. Matching these needs to a spot in your yard will make the rest of your gardening tasks much easier.
Light and Exposure
Most begonias prefer a location with partial shade or filtered sunlight. In many parts of the country, the afternoon sun is too intense for their delicate foliage. A spot that receives gentle morning sun and shade from 2:00 PM onwards is often ideal.
If your garden is very shady, begonias will still grow, but they may produce fewer flowers and become slightly "leggy" as they reach for the light. On the other hand, if they get too much direct sun, the leaves may turn yellow or develop brown, crispy edges. If you have a sunny spot, look for specifically labeled "sun-tolerant" wax begonias, which have been bred to handle more light than their tuberous cousins.
Protection from the Elements
Begonias have fleshy, succulent-like stems that are relatively brittle. This means they can be easily damaged by strong winds or heavy, driving rain. When choosing a spot in the ground, look for areas that offer some natural protection.
Planting near a fence, a wall, or under the shelter of larger shrubs can provide a windbreak. This keeps the plants upright and prevents the heavy flower heads of tuberous varieties from snapping off during a summer storm. Hanging Begonias are better suited to baskets and tall planters.
Drainage is Essential
The most important factor for begonia health is drainage. Drainage is simply how fast water leaves the soil. Begonias hate "wet feet," which means they do not like to sit in soggy, saturated earth. If the soil stays too wet for too long, the tubers or roots can rot.
To test your drainage, observe the area after a heavy rain. If puddles remain for several hours, the soil may be too heavy or contain too much clay. We recommend choosing a slightly elevated spot or amending the soil to ensure excess water can move away from the plants freely.
Key Takeaway: Choose a sheltered spot with dappled light and excellent drainage. Protecting begonias from the harsh afternoon sun and heavy winds will keep the foliage lush and the stems intact.
When to Plant Begonias in the Ground
Timing is one of the most critical parts of planting begonias. Because these are tropical plants, they have no tolerance for frost. Planting too early in a cold, damp spring can cause the tubers to sit dormant and eventually rot before they ever have a chance to sprout.
Wait for Warm Soil
We recommend waiting until the threat of frost has completely passed and the soil has warmed up. Ideally, the soil temperature should be at least 60°F before you put begonias in the ground. If the soil feels cold to the touch, it is better to wait another week.
Watch the Nighttime Temperatures
Nighttime air temperatures are also a great guide. Wait until the lows are consistently above 50°F to 60°F. In most regions, this happens a few weeks after the average last frost date. If you live in a colder climate, you might choose to start your tubers indoors in pots about 6 to 8 weeks before the last frost to give them a head start, then transplant them into the garden once the weather is reliably warm.
Seasonal Shipping
When you order from us, we time our shipping based on your USDA hardiness zone. Your order will typically arrive about two weeks before the ideal planting time for your area. This ensures the tubers arrive in prime condition and are ready to go into the ground or a starting pot as soon as your local weather allows.
Preparing the Soil for Planting
Before you dig your first hole, taking a few minutes to prepare the soil will pay off throughout the summer. Begonias thrive in light, rich soil that is full of organic matter.
Amending the Soil
If your garden soil is heavy clay or very sandy, you can improve it by adding compost or peat moss. Compost adds essential nutrients and improves the soil's texture. For begonias, a "fluffy" soil texture is best. It allows the delicate roots to spread easily and ensures that air can reach the root zone.
If you are concerned about drainage, you can mix in a small amount of perlite or coarse sand. This creates more space between soil particles for water to flow through. Aim for a mix that is roughly one-third organic matter and two-thirds native soil.
Fertilizer Basics
It is helpful to mix a balanced, slow-release fertilizer into the soil at planting time. A general-purpose 10-10-10 or 20-20-20 formula works well. Follow the package instructions for the correct amount. This provides a steady supply of nutrients as the plant begins its active growth phase. Avoid over-fertilizing at the start, as you want to encourage a strong root system before focusing on heavy foliage growth.
Step-by-Step Guide to Planting Tuberous Begonias
Planting tuberous begonias is slightly different from planting standard perennials because of the shape of the tuber. Following these steps ensures the plant grows in the right direction and stays healthy.
1. Identify the Top of the Tuber
Begonia tubers look like small, brown, hairy discs. If you look closely, one side is slightly indented or cupped (concave), while the other side is rounded (convex). The indented, hollow side is the top. This is where the pinkish buds or "eyes" will eventually emerge. Always plant with the hollow side facing up.
2. Dig the Hole
Dig a shallow hole for each tuber. You do not need to go very deep. The goal is to have the top of the tuber covered by about 1 inch of soil. If you plant them too deep, the sprouts may struggle to reach the surface, and the tuber is more likely to rot in cool, damp soil.
3. Spacing Your Begonias
Proper spacing allows for air circulation, which helps prevent fungal issues like powdery mildew later in the season.
- Tuberous Begonias: Space these about 10 to 12 inches apart.
- Wax Begonias: These can be spaced slightly closer, about 6 to 10 inches apart, depending on how quickly you want the "carpet" effect.
4. Placement and Backfilling
Set the tuber into the hole with the hollow side up. Gently fill the hole with soil, pressing down very lightly with your hands to remove any large air pockets. Do not pack the soil firmly; begonias prefer a loose environment.
5. Initial Watering
After planting, water the area lightly to settle the soil. Be careful not to overwater at this stage. Until you see green growth appearing above the soil line, the tuber only needs enough moisture to stay hydrated. Too much water on a dormant tuber can lead to decay.
What to Do Next:
- Check the orientation of your tubers (hollow side up).
- Ensure the planting depth is exactly 1 inch.
- Give each plant enough elbow room for air to flow.
- Water lightly and wait for the first sprouts.
Planting Wax Begonias and Started Plants
If you are planting wax begonias or tuberous begonias that have already been started in pots, the process is even simpler. A container-ready choice like Begonia Hanging Pink Balcony also works well.
Digging the Hole
Dig a hole that is just as deep and twice as wide as the current root ball of the plant. This extra width allows you to fill the space with loose, amended soil, making it easy for the roots to expand into their new home.
Transplanting Gently
Gently remove the plant from its nursery pot. If the roots are tightly coiled around the soil (root-bound), lightly tease them outward with your fingers. Place the plant in the hole so that the top of the root ball is level with the surrounding soil surface. Avoid burying the stems deeper than they were in the pot, as this can cause stem rot.
Settling the Soil
Fill in around the root ball with soil and press down gently. Water the plant thoroughly immediately after transplanting. This helps the roots make contact with the new soil and reduces transplant shock. Because these plants already have leaves, they will require more consistent watering than a dormant tuber.
Water Correctly, Not Constantly
Watering is the area where most gardeners face challenges with begonias. The "Simple Gardening Rule" for begonias is: water deeply, then let the soil dry out slightly before watering again.
Check the Soil Surface
Instead of watering on a set schedule, use your finger to check the soil. If the top inch of soil feels dry, it is time to water. If it still feels damp, wait another day or two. Begonias store water in their thick stems and leaves, so they can handle a brief period of dry soil better than they can handle a saturated environment.
Where to Water
When watering begonias in the ground, try to apply water at the base of the plant rather than over the top of the foliage. Wet leaves in a shady environment can encourage fungal diseases. For tuberous begonias, try to avoid getting water directly into the "hollow" of the tuber if it is still exposed, as standing water there can cause rot.
Adjust for Weather
During a heatwave, your begonias will use water more quickly and may need a drink every day or two. During a rainy spell, you may not need to water at all for a week or more. Always let the weather and the feel of the soil be your guide.
Feeding for Continuous Blooms
Begonias are "heavy feeders," meaning they use a lot of nutrients to keep producing those spectacular flowers all season long. While the slow-release fertilizer you added at planting time provides a good base, a little extra boost every few weeks will keep them looking their best.
Liquid Fertilizer
Starting about a month after planting, you can use a water-soluble fertilizer formulated for flowering plants. A "bloom booster" formula with a higher middle number (phosphorus) can encourage more flower production. We suggest applying this every 2 to 3 weeks.
Follow the Label
Always follow the mixing instructions on the fertilizer label. It is often better to use a slightly weaker solution more frequently than to use a very strong solution all at once. If the plants look healthy and are blooming well, you are on the right track. If the leaves are dark green but there are no flowers, you may be using too much nitrogen.
Maintenance and Grooming
Begonias are generally low-maintenance, but a little grooming keeps them looking tidy and encourages more blooms.
Deadheading
Deadheading is the process of removing faded or spent flowers. For many tuberous begonias, the old flowers will eventually drop off on their own. However, removing them manually prevents them from resting on the lower leaves, where they can sometimes rot or encourage mold. Simply pinch off the flower stem about an inch below the base of the flower.
Dealing with Pests
In the garden, begonias are relatively resistant to most pests. Deer and rabbits usually find the leaves unappealing, which is a big win for many home gardeners. However, keep an eye out for slugs and snails, especially in damp, shady areas. These pests love the succulent stems of begonias. If you see jagged holes in the leaves, a simple organic slug bait or a saucer of beer can usually solve the problem.
Preventing Powdery Mildew
Powdery mildew looks like a light dusting of white flour on the leaves. It usually happens in late summer when the air is humid and air circulation is poor. To prevent this, ensure your plants are spaced correctly and try to keep the foliage dry when watering. If it does appear, an organic fungicide or a simple mix of water and baking spray can help manage it.
What to Do at the End of the Season
In most of the United States, begonias are treated as annuals because they cannot survive freezing temperatures. However, tuberous begonias can be saved and replanted the following year.
Lifting Tubers
Once the first light frost hits and the foliage begins to yellow or blacken, it is time to lift your tuberous begonias. Carefully dig up the tubers, being mindful not to nick them with your shovel. Cut the stems back to about an inch above the tuber.
Curing and Storage
Place the tubers in a dry, shady spot (like a garage or porch) for a few days to "cure." Once the soil on them has dried, gently brush it off. Store the tubers in a cool, dark, and dry place for the winter. Many gardeners keep them in a box filled with dry peat moss or sawdust. They should stay dormant until you are ready to start the process all over again next spring.
Wax Begonias
Wax begonias are more difficult to overwinter as tubers because they have fibrous roots. Most gardeners choose to treat these as annuals and start with fresh plants each year. For a trailing container, Begonia Hanging Golden Balcony is another option. Alternatively, you can dig them up before the first frost, pot them, and bring them inside to grow as houseplants during the winter.
Common Myths About Planting Begonias
When searching for advice on how to plant begonias in the ground, you may encounter some common misconceptions. Clearing these up helps set realistic expectations for your garden.
- Myth: Begonias need total shade. While they don't like scorching sun, most begonias actually need some light to produce flowers. Deep, dark shade will result in beautiful leaves but very few blooms.
- Myth: You must water them every day. Overwatering is the most common cause of failure. Begonias prefer to be slightly on the dry side rather than sitting in mud.
- Myth: They are "hard" to grow. If you get the temperature and the drainage right, begonias are actually quite self-sufficient. They don't require constant pruning or complex care.
Safety and Pets
It is important to note that begonias contain calcium oxalates, which can be toxic if ingested by pets or children. While most animals find the taste bitter and will avoid them, it is a good idea to plant them in areas where curious pets won't be tempted to nibble on the stems or tubers. Always wash your hands after handling tubers if you have sensitive skin, as the sap can occasionally cause mild irritation.
Key Takeaway: Success with begonias in the ground is built on warmth and drainage. By waiting for the soil to warm and ensuring water doesn't pool around the roots, you've solved 90% of potential gardening challenges.
FAQ
Can I plant begonia tubers directly in the ground?
Yes, you can plant begonia tubers directly in the ground once the soil is warm (at least 60°F) and the threat of frost is gone. In cooler climates, many gardeners prefer to start them in pots indoors 6-8 weeks early to enjoy a longer blooming season, but direct planting works perfectly well if your growing season is long enough.
Which side of the begonia tuber faces up?
The hollow or indented side of the tuber should always face up. This is where the new stems and flowers will grow from. The rounded, smooth side should face down into the soil. If you accidentally plant it upside down, the plant may still grow, but it will take much longer to emerge and will be significantly weaker.
How deep should I plant begonias in the ground?
Begonia tubers should be planted about 1 inch deep. If you are transplanting a begonia that is already growing in a pot, plant it at the same depth it was in the container. Planting too deep can lead to stem or tuber rot, while planting too shallow can cause the plant to dry out or become unstable.
Do begonias come back every year in the garden?
In USDA zones 9-11, some begonias may survive the winter in the ground. However, in most of the United States (zones 3-8), begonias are tropical and will die if left outside in the frost. To keep them for next year, you must dig up the tubers in the fall and store them in a cool, dry place indoors.
Conclusion
Planting begonias in the ground is a rewarding way to add dependable, high-impact color to your landscape. By choosing a sheltered spot with dappled light, preparing the soil for excellent drainage, and waiting for the warm weather of late spring, you set the stage for a spectacular display. Whether you prefer the massive blooms of tuberous varieties or the constant color of wax begonias, these plants are sure to become a highlight of your summer garden.
At Longfield Gardens, we take pride in providing high-quality tubers and plants that help you achieve these beautiful results. Gardening should be a source of joy and relaxation, and with a few simple steps, you can enjoy the lush, tropical beauty of begonias all season long.
"The secret to beautiful begonias isn't a green thumb—it's simply waiting for the warmth of the sun and giving the roots a well-drained home."
We are here to support you with quality products and practical advice every step of the way. Ready to start your shade garden transformation? Browse our selection of begonias and get ready for a season of incredible color.