Introduction
As the crisp autumn air begins to settle over the garden, many of us look at our vibrant begonias and wish we could hold onto that beauty just a little longer. These versatile plants are a highlight of the summer garden. They offer everything from the massive, rose-like blooms of tuberous varieties to the mesmerizing, metallic foliage of Rex types. The good news is that you do not have to say goodbye to these plants when the first frost looms.
At Longfield Gardens, we believe that gardening is most rewarding when you can extend the life of your favorite plants across the seasons. Bringing begonias indoors for the winter is a common practice that allows you to preserve your investment and enjoy their presence year-round. Whether you want to keep them growing as houseplants or tuck them away for a winter nap, the process is straightforward once you know which type of begonia you are growing. For a broader overview, see this guide to begonias.
This guide will help you identify your begonia type and provide the simple steps needed to transition them from the porch to the parlor. We will cover the specific needs of different varieties so you can ensure your plants return even stronger next spring. With a few basic adjustments to your routine, you can successfully keep your begonias healthy through the coldest months of the year.
Identifying Your Begonia Type
Before you pick up a trowel or a pair of snips, you need to know which kind of begonia is currently sitting in your garden beds or containers. Begonias are a massive family with thousands of species. In the gardening world, we usually group them into four main categories based on how they grow. Each group has a different strategy for surviving the winter.
Tuberous Begonias
These are the showstoppers often found in hanging baskets and shaded containers. They are known for their large, spectacular flowers that can resemble roses or camellias. Tuberous begonias grow from a thick, potato-like underground structure called a tuber. Because they are native to regions with distinct wet and dry seasons, they naturally want to go dormant in the winter. You cannot keep these growing as active houseplants all winter; they need a rest to bloom again next year. Learn more in this guide to wintering over begonia plants.
Wax Begonias
Wax begonias are the classic "bedding" plants often used in mass plantings or border edges. They have fleshy, succulent-like leaves that look polished or "waxy." They produce small, constant clusters of red, white, or pink flowers. These begonias have fibrous roots and do not go dormant. They are very happy to transition into indoor life and can continue blooming on a sunny windowsill throughout the winter.
Cane-Stemmed and Angel Wing Begonias
These begonias are easily identified by their tall, bamboo-like stems and leaves that are shaped like a bird's wing. Many varieties, like the popular ‘Dragon Wing’ begonia, are prized for their elegant, drooping flower clusters. Like wax begonias, these are fibrous-rooted plants that do not require a dormancy period. They make excellent, large-scale houseplants and can grow quite tall if given enough light and space.
Rex and Rhizomatous Begonias
Rex begonias are grown primarily for their incredible foliage. Their leaves feature swirls of silver, purple, pink, and deep green. Rhizomatous begonias are similar but are identified by thick stems that creep along the surface of the soil. These types are already very popular as year-round houseplants. If you have had them outside for the summer to enjoy the humidity, they will transition back indoors easily as long as you maintain their moisture levels.
Key Takeaway: Your winter strategy depends on the roots. Tuberous begonias must go dormant and be stored dry. Wax, Cane, and Rex begonias can stay active as indoor houseplants.
How to Overwinter Tuberous Begonias
Tuberous begonias are not hardy in most of the United States. When the temperatures drop, the top growth will naturally begin to yellow and die back. This is the plant's way of telling you it is ready to store its energy in the tuber for next year. Instead of fighting this process, you should help the plant enter its rest period.
Inducing Dormancy
In late September or October, as the nights get cooler, stop fertilizing your tuberous begonias. You should also begin to reduce the amount of water they receive. A light frost may blacken the leaves, which is actually a helpful signal to the plant to shut down. Once the foliage has turned yellow or been hit by a light frost, it is time to bring them in.
Lifting and Cleaning the Tubers
Carefully dig the tubers out of the soil or remove them from their pots. Be gentle, as the tubers can be brittle. Use your fingers to brush away most of the loose soil. Cut the stems back to about one inch above the tuber. Do not force the stems to break off; if they are still firmly attached, let them dry for a few more days, and they will eventually fall off naturally.
Curing and Storage
Place the cleaned tubers in a cool, dry, and airy spot for about a week. This "curing" process allows the outer skin to toughen up, which prevents rot during storage. Once they are dry to the touch, place them in a cardboard box or a paper bag filled with dry peat moss, vermiculite, or sawdust.
Store the box in a dark, cool place where temperatures stay between 40°F and 50°F. A cool basement or an insulated crawl space works well. Avoid areas that might freeze, such as an unheated garage in a cold climate. Check on them once a month to ensure no rot is starting and that they haven't completely shriveled up.
What to Do Next for Tuberous Begonias
- Stop watering and feeding in early autumn.
- Wait for the first light frost to trigger dormancy.
- Dig tubers carefully and trim stems to one inch.
- Cure in a dry spot for 7 to 10 days.
- Store in dry peat moss in a cool, dark location.
Transitioning Begonias to Indoor Houseplants
If you are growing wax, cane, or Rex begonias, you don't need to put them in a box in the basement. These plants can stay green and beautiful all winter long. However, the move from the high humidity and bright light of the outdoors to the dry, heated air of a home can be a shock. A successful transition requires a gradual approach.
Timing the Move
The best time to bring your begonias inside is before you turn on your home's heating system. Forced-air heat creates a very dry environment that can cause begonias to drop their leaves in protest. Bringing them in while the windows are still open and the indoor air is relatively humid helps them acclimate. Aim to move them indoors when nighttime temperatures consistently fall below 55°F.
Pest Inspection and Cleaning
Before any plant enters your home, it needs a thorough inspection. Check the undersides of leaves and the joints of the stems for common hitchhikers like aphids, mealybugs, or spider mites. A quick spray with a garden hose can dislodge most pests. For an extra layer of protection, you can wash the leaves with a mild soapy water solution or treat the plant with neem oil according to the package directions.
Pruning for Indoor Success
Outdoor begonias often grow quite large and bushy. Before bringing them in, give them a light pruning. This makes them easier to manage on a windowsill and reduces the amount of foliage the roots have to support while they adjust to lower light. You can trim back long, leggy stems by about one-third. This will encourage the plant to grow more compactly and stay lush indoors.
Managing Light and Humidity
Inside, begonias need the brightest light you can provide without putting them in harsh, direct midday sun. An east-facing or south-facing window is usually ideal. Because modern homes are quite dry in the winter, humidity is the biggest challenge. For additional guidance, see these indoor winter care tips for begonias.
A simple "pebble tray" is a gardener's best friend. Fill a shallow tray with pebbles and add water until it is just below the top of the stones. Place your begonia pot on top of the pebbles. As the water evaporates, it creates a small microclimate of humidity right around the leaves. Avoid misting the leaves directly, as begonias can be prone to mildew if their foliage stays wet for too long.
"A gradual transition is the best way to prevent leaf drop. Start by bringing the plants inside at night and moving them back out during the day for a week to help them adjust to the new environment."
Winter Care for Indoor Begonias
Once your begonias are settled in their indoor winter home, their needs will change. The shorter days and cooler temperatures mean the plants are not growing as vigorously as they were in July. To keep them happy, you must adjust your care routine.
Watering Rules
The number one mistake gardeners make with indoor begonias is overwatering. In the winter, the soil stays damp much longer because evaporation is slower. Always check the soil with your finger before adding water. If the top inch of soil feels dry, give the plant a drink. If it feels moist, wait a few days. Begonias are susceptible to root rot, so it is better to let them be slightly dry than constantly soggy. These begonia growing tips include additional watering guidance.
Feeding and Fertilizing
Most begonias do not need fertilizer during the winter. Because they aren't producing a lot of new growth, the salts in fertilizer can build up in the soil and burn the roots. Stop feeding your plants in October and wait until you see new, vibrant growth in late February or March to start a regular fertilization schedule again.
Temperature Consistency
Begonias prefer temperatures that are comfortable for humans. They thrive when daytime temperatures are between 65°F and 75°F and nighttime temperatures stay above 55°F. Keep them away from drafty doors or windows, as well as direct blasts from heating vents. These sudden temperature swings can cause the plant stress and lead to yellowing leaves.
Growing Begonias from Cuttings
If you have a very large begonia that won't fit on your windowsill, or if you want to "back up" your favorite plants, taking cuttings is a fantastic winter strategy. This allows you to save the genetics of the plant in a much smaller footprint.
How to Take a Stem Cutting
Choose a healthy, non-flowering stem and cut a 4-to-6-inch piece just below a leaf node (the spot where a leaf attaches to the stem). Remove the lower leaves so you have a clean stem to insert into your growing medium. For more detail, see this guide to begonia propagation by stem cuttings.
Rooting Methods
You can root begonia cuttings in two simple ways:
- Water Rooting: Place the stem in a small jar of clean water. Change the water every few days to keep it fresh. Once roots are about an inch long, transplant the cutting into a small pot with fresh potting soil.
- Soil Rooting: Dip the end of the stem in rooting hormone (optional) and tuck it into a pot filled with a light, damp seed-starting mix. Cover the pot with a clear plastic bag to create a mini-greenhouse effect.
Cuttings taken in the fall will grow slowly over the winter. By the time spring arrives, you will have a well-established young plant ready to be hardened off and moved back into the garden. This is a very rewarding way to multiply your garden collection for free.
Steps for Winter Cuttings
- Select a 4-inch healthy stem without flowers.
- Cut just below a node and remove lower leaves.
- Place in water or damp potting mix.
- Keep in a warm, bright spot out of direct sun.
- Pot up once roots are established.
Dealing with Common Winter Issues
Even with the best care, you might notice your begonias looking a bit "tired" by mid-January. Don't panic; this is usually a simple fix. We recommend changing only one variable at a time when troubleshooting so you can see what actually works.
Leaf Drop
If your begonia suddenly sheds several leaves after you bring it inside, it is likely just reacting to the change in environment. As long as the stems are firm and there is some green growth remaining, the plant will usually recover. Ensure it is getting enough light and that you aren't overwatering it while it is in this vulnerable state.
Yellowing Leaves
Yellow leaves often signal a watering issue. Usually, it means the soil is staying too wet. Check the drainage holes in your pot to make sure they aren't blocked. If the soil is soggy, let it dry out completely before watering again. Occasionally, yellowing can also mean the plant is too cold. Ensure it isn't touching a freezing-cold windowpane at night.
Powdery Mildew
Because begonias like humidity but can have poor air circulation indoors, they sometimes develop powdery mildew. This looks like a light dusting of white flour on the leaves. To prevent this, make sure the plants aren't crowded too closely together. If you see it appearing, you can treat the leaves with a solution of one part milk to nine parts water, or use a garden-safe fungicide.
Can Any Begonias Stay Outside?
While most begonias we grow in containers are tropical and will die in the cold, there are a few species known for their hardiness. The most common is Begonia grandis, often called the Hardy Begonia.
The Hardy Begonia (Begonia grandis)
This plant is a wonder in the shade garden. It produces beautiful pink flowers in late summer and can survive temperatures down to USDA Zone 6. Unlike its tropical cousins, this begonia survives the winter by producing small bulbils (tiny clones) that drop to the ground and sprout the following year.
Protecting Hardy Varieties
If you live in a colder region and want to ensure your Hardy Begonias return, a little extra care goes a long way. After the first frost kills the top growth, do not cut it back immediately. Let the plant naturally collapse. Then, apply a 2-to-3-inch layer of organic mulch, such as shredded leaves or straw, over the area. This insulation helps protect the crown of the plant from extreme freeze-thaw cycles.
In the spring, be patient. Hardy begonias are famous for being late starters. They often don't emerge until the soil is truly warm, sometimes as late as June. Don't assume they didn't make it; give them time to wake up.
Preparing for Spring Re-entry
As the days grow longer in late February, you will notice your indoor begonias starting to push out new, bright green leaves. This is the signal to start waking them up for the coming season.
Refreshing the Soil
For begonias that lived as houseplants, spring is the perfect time for a fresh start. You don't necessarily need a larger pot, but replacing the top few inches of soil with fresh, high-quality potting mix can provide a boost of nutrients. If the plant has become root-bound, move it to a pot that is only one size larger.
Waking Up Tuberous Begonias
In March, bring your stored tubers out of the basement. Inspect them for any soft spots. Place them on top of a tray of damp potting soil with the hollow side facing up. Keep them in a warm, bright spot. Once you see small pink or green "eyes" (buds) sprouting, you can plant them in their permanent containers, keeping the top of the tuber just at the soil surface. This begonia wintering guide covers the spring wake-up process in more detail.
Hardening Off
The most important step in the spring is "hardening off." Just as the move indoors was a shock, the move back outdoors can be intense. Start by placing your plants in a shaded, protected spot for an hour or two a day, gradually increasing their time outside over two weeks. This allows the leaves to toughen up so they don't get sunburned or wind-whipped.
Conclusion
Bringing your begonia plants inside for the winter is a wonderful way to keep the joy of gardening alive throughout the year. Whether you choose to keep them as vibrant houseplants or store them as dormant tubers, the process is simple and highly effective. By matching your care to the specific type of begonia you have, you can ensure these beautiful plants remain a part of your garden for many years to come.
At Longfield Gardens, we want to help you make the most of every plant in your yard. Taking a few minutes this autumn to bring your begonias indoors is a small effort that pays off with massive rewards when the first warm days of spring arrive. You’ll save money, preserve your favorite varieties, and enjoy the calming presence of greenery during the winter months.
Final Thought: "Don't let the first frost be the end of your begonia season. With a sunny window or a cool basement corner, you can easily carry your garden's beauty through to next year."
For your next steps, we suggest checking your local weather forecast to see when that first 50°F night is coming. Gather your supplies—some clean pots, fresh soil, and a few cardboard boxes—and get ready to give your begonias the winter protection they deserve. Happy gardening!
FAQ
Can I keep tuberous begonias as houseplants during the winter?
It is not recommended to keep tuberous begonias active all winter. They are genetically programmed to require a dormancy period to recharge their energy. If you try to keep them growing, they often become weak, leggy, and may fail to bloom the following summer. It is best to let them rest in a cool, dry place.
Why are my begonia leaves falling off now that I've moved it inside?
Leaf drop is a common reaction to the change in humidity and light levels between the outdoors and indoors. It is essentially the plant's "reset" button. As long as you provide bright indirect light and maintain humidity with a pebble tray, the plant should stabilize and grow new leaves that are better adapted to indoor life. The indoor begonia care guide offers additional troubleshooting advice.
Do I need to fertilize my begonias while they are indoors?
Generally, no. Most begonias grow very slowly during the winter months due to lower light levels. Adding fertilizer when the plant isn't actively growing can lead to a buildup of minerals that might damage the roots. Wait until you see vigorous new growth in the spring before you resume a regular feeding schedule.
How do I know if my begonia tuber is still alive in storage?
A healthy tuber should feel firm and heavy for its size, similar to a fresh potato. If you gently squeeze it and it feels mushy or hollow, it has likely rotted or dried out completely. In the spring, the appearance of small, colorful "eyes" or buds on the surface is the definitive sign that your tuber is ready to grow.
