Introduction
One of the most rewarding moments in a gardener's year is seeing the lush, vibrant blooms of a begonia reach their peak in late summer. Whether you enjoy the cascading petals of a hanging begonia or the bold, colorful leaves of a Rex begonia, these plants bring a tropical elegance to any space. The good news is that you do not have to say goodbye to these beauties when the temperature begins to drop. By learning how to overwinter begonia plants, you can enjoy larger, more vigorous displays year after year without starting from scratch each spring.
At Longfield Gardens, we want to help you make the most of your garden investments. Many home gardeners are surprised to learn that begonias are actually perennials in their native tropical climates. While they cannot survive a frost in most parts of the United States, they are remarkably resilient if you provide the right winter environment. Success simply requires a little bit of timing and the correct storage method for the specific type of begonia you are growing.
This guide will walk you through the simple steps of identifying your begonia variety and preparing it for the winter months. We will cover how to store dormant tubers, how to transition potted begonias into houseplants, and how to ensure your plants return even stronger next spring. With a few basic techniques, you can keep your favorite begonias thriving for many seasons to come.
Understanding Your Begonia Type
Before you start preparing for winter, you must identify which type of begonia you have. Begonias are a diverse group of plants, and they do not all react to the cold in the same way. Some varieties prefer to go completely dormant and spend the winter as a dry tuber. Others are happy to keep growing as houseplants on a sunny windowsill. Knowing the difference is the first step toward successful overwintering.
Tuberous Begonias
Tuberous begonias are famous for their large, rose-like flowers and their ability to brighten up shady corners. Varieties like the Non-Stop begonia collection or the cascading Illumination begonias fall into this category. These plants grow from a thick, potato-like structure called a tuber. In the wild, these tubers act as energy reservoirs that allow the plant to survive a dry season. In your garden, this means the plant needs a mandatory period of dormancy. You cannot keep tuberous begonias blooming all winter; they must rest to bloom again next year.
Wax and Fibrous Begonias
Wax begonias are the classic bedding plants often used in garden borders or patio pots. They have succulent stems and shiny, rounded leaves that can be green or bronze. Unlike tuberous types, wax begonias have a fibrous root system. They do not have a natural dormancy period. If you want to save these, you must bring them indoors and treat them as houseplants. They are quite hardy and can often continue to flower through the winter if they get enough light.
Cane and Angel Wing Begonias
Cane-like begonias, including the popular Dragon Wing begonias, are known for their tall, upright stems and wing-shaped leaves. Like wax begonias, these are fibrous-rooted and stay active year-round. They are particularly popular for overwintering because they adapt well to indoor environments. Their architectural shape makes them attractive indoor decorations during the snowy months.
Rex and Rhizomatous Begonias
These begonias are grown primarily for their stunning foliage. Rex begonias feature "electrifying" patterns of silver, purple, and red, while rhizomatous begonias have thick stems that creep along the soil surface. Both types function well as houseplants. They do not go dormant, but they do require high humidity to stay healthy when the indoor air becomes dry from winter heating.
Key Takeaway: Determine if your plant has a tuber or fibrous roots. Tuberous begonias must go dormant and be stored dry, while fibrous types (Wax, Cane, Rex) should be brought inside as active houseplants.
How to Overwinter Tuberous Begonias
Overwintering tuberous begonias is a straightforward process that mimics the plant’s natural cycle. The goal is to let the plant finish its growth for the year and then protect the tuber from freezing. When done correctly, the tuber will actually grow larger each year, leading to more impressive blooms the following summer.
Preparing for Dormancy
As summer winds down and the nights become cooler, you will notice your begonias starting to look a bit tired. This is a natural signal that the plant is preparing for rest. In late summer or early fall, you should stop fertilizing your tuberous begonias. This encourages the plant to stop producing new foliage and start storing energy in the tuber.
You should also begin to reduce the frequency of watering. Let the soil dry out more than usual between waterings. This helps the plant understand that the growing season is ending. Many gardeners wait until the first light frost kills the top of the foliage before taking action. A light frost that turns the leaves black will not hurt the tuber as long as the ground or the pot does not freeze solid.
Digging and Lifting Tubers
Once the foliage has yellowed or been nipped by a light frost, it is time to lift the tubers. If the plants are in the ground, use a garden fork to gently lift the soil around the plant. Be careful not to cut or bruise the tuber, as wounds can lead to rot during storage. If your begonias are in containers, you can simply tip the pot over and gently remove the plant.
After lifting, cut the stems back to about one or two inches above the tuber. Do not try to pull the stems off, as you might damage the "eyes" or growth points on the top of the tuber. Gently shake off the excess soil, but do not worry about getting them perfectly clean yet.
The Curing Process
Curing is a vital step that many beginners skip. It involves letting the tubers dry out in a protected area for several days or even a couple of weeks. Find a dry, shady spot that is away from direct sunlight and protected from rain and frost. A garage, shed, or basement works well.
Lay the tubers out on a tray or a piece of newspaper. During this time, the remaining stem will wither and eventually fall off on its own. The outer skin of the tuber will also toughen up slightly. This "skinning over" helps the tuber retain its internal moisture while preventing external mold from taking hold. Once the stems have fallen off and the tubers feel dry to the touch, you can gently brush away any remaining dry soil.
Storing for the Winter
Proper storage is about finding the "Goldilocks" zone: not too hot, not too cold, and not too wet. The ideal temperature for storing begonia tubers is between 40°F and 50°F. If the area is too warm, the tubers might try to sprout too early. If it is too cold, they may freeze and perish.
You have several options for storage media:
- Peat moss or Vermiculite: These are excellent because they provide insulation and absorb any excess moisture.
- Sawdust or Wood Shavings: A traditional choice that keeps tubers separated and dry.
- Paper Bags: For a simple approach, place each individual tuber in a small paper bag and then place all the bags inside a cardboard box.
The most important rule is to make sure the tubers are not touching each other. If one tuber happens to rot, you do not want the issue to spread to the entire collection.
Action List for Tuberous Begonias:
- Stop fertilizing in late August or early September.
- Reduce water as the weather cools.
- Lift tubers after the first light frost or once leaves yellow.
- Cure in a dry, frost-free area for 1–2 weeks.
- Store in a cool, dark place (40–50°F) in dry peat or paper bags.
Overwintering Begonias as Houseplants
If you have wax, cane, or Rex begonias, you do not need to worry about tubers or dormancy. Instead, you can bring these plants inside and enjoy them as part of your indoor decor. Because these begonias are naturally shade-tolerant, they often adapt to indoor light levels better than many other garden plants.
The Indoor Transition
The transition from the Great Outdoors to a living room can be a shock for any plant. To make this easier, bring your begonias inside before the outdoor temperatures drop below 50°F. If you wait until it is freezing outside and then move them into a heated house, the plants may drop many of their leaves in protest.
Before bringing them in, give your plants a thorough inspection. Check the undersides of leaves and the stems for any hitchhiking insects. A gentle spray with a garden hose can wash away most pests. You might also want to repot them if they have been in the ground. Use a high-quality, soil-free potting mix rather than garden soil. Garden soil is too heavy for pots and can bring pests or diseases into your home.
Light and Temperature Needs
Indoors, begonias prefer bright, indirect light. A window facing east or west is usually ideal. Avoid placing them in direct, hot afternoon sun, which can scorch their leaves. If your home is particularly dark during the winter, you can use a simple grow light to keep them happy.
Most begonias are comfortable at the same temperatures humans enjoy. Keep them away from cold drafts, such as near an entryway door, and away from direct heat sources like radiators or heating vents. Extreme temperature fluctuations are the most common cause of leaf drop.
Managing Humidity and Water
The biggest challenge for indoor begonias is the dry air caused by home heating systems. Rex begonias, in particular, crave humidity. You can create a more humid microclimate by using a pebble tray. Simply fill a shallow tray with pebbles and add water until it is just below the top of the stones. Place your pot on the pebbles. As the water evaporates, it creates a pocket of moisture around the plant.
When it comes to watering, the "less is more" rule applies. Indoor plants grow much more slowly in the winter and need less water than they did outside. Always check the soil first. Stick your finger about an inch into the soil; if it feels dry, it is time to water. If it feels moist, wait a few more days. Overwatering is the fastest way to cause root rot in begonias.
Winter Maintenance
You do not need to fertilize your begonias during the winter months. Since they aren't growing actively, those extra nutrients can actually build up in the soil and harm the roots. Simply keep the plants clean by removing any yellowing or dead leaves. This keeps the plant looking tidy and prevents mold from forming on the soil surface.
What to do next for indoor begonias:
- Bring plants inside before nights drop below 50°F.
- Use a pebble tray to boost humidity in dry rooms.
- Place in bright, indirect light.
- Water only when the top inch of soil feels dry.
- Wait until spring to resume fertilization.
The Dormant Pot Method
If you have tuberous begonias growing in large containers or heavy pots, you might not want to go through the trouble of digging up the tubers. There is an easier way known as the "dormant pot" method. This is perfect for gardeners who have limited space or want to keep their container designs intact.
Instead of lifting the tubers, simply move the entire pot into a cool, dry area like a basement or an unheated (but frost-free) garage. Once the foliage has died back, cut the stems to the soil line. Do not water the pot at all during the winter. The soil will dry out completely, and the tuber will go to sleep right where it grew.
The pot itself provides a layer of insulation for the tuber. In the spring, you can simply move the pot back into the light, give it a fresh layer of compost or potting soil on top, and start watering to wake the plant up. This method is very successful in regions with stable, cool winters.
Handling Common Winter Challenges
Gardening is a learning process, and overwintering is no exception. Even experienced gardeners face challenges when bringing the outdoors in. The key is to respond calmly and make small adjustments.
Dealing with Leaf Drop
It is very common for begonias to drop some leaves when they first move indoors. This is the plant's way of adjusting to lower light levels. Do not panic and start overwatering or fertilizing to "fix" it. Simply give the plant time to acclimate. Usually, it will grow new leaves that are better adapted to indoor light within a few weeks.
Managing Pests Indoors
Occasionally, you might notice small gnats or whiteflies on your indoor begonias. Fungus gnats are usually a sign that the soil is staying too wet. Letting the soil dry out more between waterings often solves the problem. For other pests, a simple solution of insecticidal soap or a gentle wipe with a damp cloth is usually all that is needed. Avoid using harsh chemicals indoors; simple physical removal is often more effective and safer.
Preventing Rot in Storage
If you are storing dormant tubers, check on them once a month. If you see a tuber that looks soft or has fuzzy mold, remove it immediately so it doesn't affect the others. If a tuber has a very small soft spot, you can sometimes save it by cutting away the soft area and letting the wound dry out in a warm room for a few days before returning it to storage. However, if most of the tuber is soft, it is best to discard it and focus on the healthy ones.
Starting Begonias Again in Spring
The excitement of a new gardening season begins long before the last frost. For many gardeners, waking up their overwintered begonias is the first sign that spring is on the way.
Waking Up Tubers
About 6 to 8 weeks before the last expected frost in your area, you can bring your stored tubers out of their dark winter home. Inspect them one last time for firmness. To start them, place the tubers on top of a tray of moist potting soil. Do not bury them yet; simply press them gently into the surface.
Place the tray in a warm, bright spot. When you see small pink or green buds (eyes) starting to grow from the hollowed-out top of the tuber, it is time to pot them up. Plant them so the top of the tuber is just level with the soil surface. Be very careful with watering at this stage. Too much water before the plant has roots can cause the tuber to rot. Wait until you see actual stems and leaves before you start watering regularly.
Moving Indoor Plants Back Outside
For your wax, cane, and Rex begonias that spent the winter as houseplants, the return to the garden should be gradual. This is called "hardening off." When the nights are reliably above 50°F, move the plants to a shady, protected spot outside for a few hours a day. Gradually increase their time outside over the course of a week or two. This helps the leaves toughen up and prevents them from getting "sunburned" by the intense outdoor light.
Refreshing the Soil
Whether you kept the plant as a houseplant or stored the tuber, spring is the perfect time for fresh soil. If your begonia was in a pot all winter, the nutrients in the soil have likely been depleted. Gently remove the plant from its pot, shake off some of the old soil, and repot it with fresh, high-quality potting mix. This gives the plant a boost of nutrients just as it enters its most active growing phase.
Why Overwintering is Worth the Effort
While it is easy to buy new begonias every spring, there is a special satisfaction in seeing a plant return for a second, third, or even tenth year. Overwintering allows you to preserve specific varieties that might be hard to find again. It also saves money, which you can then use to try new and exciting varieties for other parts of your garden.
Most importantly, overwintered begonias are often much more impressive than nursery-bought starts. A tuber that has been saved for three years will be significantly larger than a one-year-old tuber. This results in a much larger plant with a higher volume of flowers. By following these simple steps, you are not just saving a plant; you are investing in a more beautiful future for your garden.
Spring Success Summary:
- Start tubers 6-8 weeks before the last frost.
- Keep soil lightly moist, never soggy, during the waking-up phase.
- Hardened off indoor plants slowly when nights stay above 50°F.
- Use fresh potting soil for a nutritional boost.
Conclusion
Overwintering begonias is a simple and rewarding way to extend the life of your favorite garden plants. Whether you are tucking tuberous begonias away for a winter nap or enjoying the colorful foliage of a Rex begonia in your living room, the process is easy enough for any gardener to master. By understanding the needs of your specific variety and providing a frost-free environment, you ensure that the beauty of summer remains with you all year long.
At Longfield Gardens, we believe that gardening should be an enjoyable journey of discovery. Every plant you save is a testament to your growing skills and a promise of more blooms to come. We are proud to provide the high-quality tubers and plants that form the foundation of these multi-year garden successes.
- Identify if your begonia is tuberous (needs dormancy) or fibrous (needs to be a houseplant).
- Protect all begonias from freezing temperatures.
- Monitor moisture levels carefully—less is almost always more during the winter.
"The secret to a spectacular begonia display often lies in the patience and care given during the quiet winter months. Saving your plants is a simple joy that pays off in a bounty of color every summer."
For more information on selecting the best begonias for your home, visit our website and explore our variety of begonia growing guides and plant collections. We look forward to helping you grow your most beautiful garden yet.
FAQ
How can I tell the difference between a wax begonia and a tuberous begonia?
The easiest way is to look at the leaves and the base of the plant. Tuberous begonias usually have larger, more pointed leaves and thick, succulent stems that emerge from a single point at the soil line (the tuber). Wax begonias are smaller, have rounded, shiny leaves, and multiple stems that form a bushy mound with a mass of thin, fibrous roots.
What should I do if my stored tubers start to sprout in February?
If your tubers sprout early, it usually means their storage area is a bit too warm. You can move them to a slightly cooler (but still frost-free) spot to slow them down. If the sprouts are already several inches long, it is best to pot them up in soil and place them in a bright window, treating them as houseplants until the weather warms up outside.
Do I need to fertilize my begonias while they are indoors for the winter?
No, you should avoid fertilizing during the winter. Most begonias grow very slowly or go completely dormant during this time, and they cannot use the extra nutrients. Adding fertilizer to a plant that isn't growing can lead to a buildup of salts in the soil, which can damage the roots. Resume feeding in the spring once you see active new growth.
Can I leave my tuberous begonias in the ground if I live in a warm climate?
If you live in USDA Zone 9 or warmer, you can often leave tuberous begonias in the ground over winter. However, they must stay dry during their dormancy. If your winter involves heavy rain, the tubers may rot in the damp soil. In these cases, it is still safer to lift them or grow them in containers that can be moved to a dry, protected area.
