Overwintering a begonia successfully requires careful planning and attention to its specific needs. These tropical plants thrive in warm, humid conditions, but when temperatures drop, they enter a dormant phase to survive the cold. Whether you’re dealing with tuberous, rhizomatous, or fibrous-rooted begonias, the approach to overwintering varies slightly. Here’s a comprehensive guide to help you protect your begonias during the colder months.
Understanding Begonia Types and Their Needs
Before diving into overwintering techniques, it’s crucial to identify the type of begonia you have, as each has unique requirements.
Tuberous Begonias: Known for their large, showy flowers, these begonias grow from tubers and are typically treated as annuals. However, with proper care, their tubers can be saved and replanted the following season.
Rhizomatous Begonias: These plants grow from rhizomes and are prized for their attractive foliage. They are generally hardier and easier to overwinter indoors.
Fibrous-Rooted Begonias: Commonly grown as bedding plants, these begonias have a fibrous root system and are often treated as annuals, though some varieties can be overwintered indoors.
Preparing Begonias for Overwintering
As temperatures begin to drop in late fall, it’s time to prepare your begonias for their winter dormancy.
Step 1: Monitor Temperature
Begonias are sensitive to cold. Once nighttime temperatures consistently fall below 50°F (10°C), it’s time to take action. For outdoor plants, this is your cue to bring them inside or protect them.
Step 2: Reduce Watering
As begonias prepare for dormancy, their water needs decrease. Gradually reduce watering to allow the soil to dry out slightly between waterings. Overwatering can lead to rot, especially during dormancy.
Step 3: Stop Fertilizing
Discontinue fertilizing your begonias 4-6 weeks before the first expected frost. This encourages the plant to slow its growth and prepare for dormancy.
Overwintering Techniques by Begonia Type
Tuberous Begonias
Method: Storing Tubers
Pros: Space-efficient, preserves the plant for the next season.
Cons: Requires careful handling to avoid rot.
- Dig Up Tubers: After the first frost, cut back the foliage to about 1 inch above the soil. Carefully dig up the tubers, taking care not to damage them.
- Clean and Dry: Gently brush off excess soil and allow the tubers to air dry for a few days in a warm, well-ventilated area.
- Store in Peat Moss: Place the tubers in a container filled with dry peat moss. Ensure they are not touching each other to prevent rot.
- Ideal Storage Conditions: Store the container in a cool, dark place with temperatures between 45°F and 55°F (7°C and 13°C). Check periodically for signs of rot or shriveling.
Rhizomatous Begonias
Method: Indoor Overwintering
Pros: Easy to manage, allows the plant to continue growing slowly.
Cons: Requires space and proper conditions indoors.
- Bring Indoors: Before the first frost, move your rhizomatous begonias indoors. Choose a location with bright, indirect light and temperatures between 60°F and 70°F (15°C and 21°C).
- Reduce Watering: Water sparingly, allowing the soil to dry out between waterings. Overwatering can cause root rot.
- Monitor for Pests: Inspect the plant regularly for pests like spider mites or mealybugs, which thrive in indoor conditions.
Fibrous-Rooted Begonias
Method: Indoor Overwintering or Cuttings
Pros: Flexible options depending on your space and preference.
Cons: Cuttings require additional care to root successfully.
- Option 1: Bring Indoors: Like rhizomatous begonias, fibrous-rooted varieties can be brought indoors and cared for in a similar manner. Place them in a bright, cool location and water sparingly.
- Option 2: Take Cuttings: Before frost, take stem cuttings and root them in water or a well-draining potting mix. Once rooted, pot them up and care for them as young plants indoors.
Common Challenges and Solutions
Overwintering begonias can be tricky, but being aware of common issues can help you address them proactively.
- Rot: Excess moisture is the primary cause of rot. Ensure proper air circulation and avoid overwatering. For tubers and rhizomes, inspect them regularly and remove any affected parts.
- Pests: Indoor begonias are susceptible to pests like spider mites and mealybugs. Regularly inspect plants and treat infestations with insecticidal soap or neem oil.
- Leggy Growth: Insufficient light can lead to leggy, weak growth. Ensure your begonias receive bright, indirect light indoors. Supplemental grow lights can be beneficial.
Spring Reawakening
As temperatures warm in spring, it’s time to revive your begonias from their dormant state.
Step 1: Gradually Reintroduce Water and Fertilizer
For tubers and rhizomes, gradually increase watering and begin fertilizing with a balanced, water-soluble fertilizer. For indoor plants, move them to a brighter location and resume regular care.
Step 2: Repot if Necessary
If your begonias have outgrown their pots, repot them into fresh, well-draining soil. This is also a good time to divide overcrowded rhizomatous begonias.
Step 3: Harden Off Outdoor Plants
Before moving begonias back outdoors, gradually acclimate them to outdoor conditions over 1-2 weeks. Start with a few hours of shade daily, increasing exposure to sunlight and outdoor temperatures.
Can I overwinter begonias in the ground?
+In mild climates (USDA zones 9-11), fibrous-rooted begonias may survive in the ground with mulch protection. However, tuberous and rhizomatous varieties typically require lifting and indoor storage.
How do I know if my begonia tubers are viable?
+Healthy tubers should feel firm and show no signs of shriveling or rot. If they feel soft or mushy, they are likely not viable.
Can I overwinter begonias in a garage?
+Garages can be suitable for storing tubers if temperatures remain consistently between 45°F and 55°F (7°C and 13°C). Avoid areas prone to freezing or extreme temperature fluctuations.
Why are the leaves on my overwintering begonia dropping?
+Leaf drop is normal during dormancy. Ensure the plant is not overwatered and provide adequate light if it’s kept indoors.
Conclusion
Overwintering begonias requires an understanding of their specific needs and a proactive approach to care. By identifying your begonia type, preparing them for dormancy, and choosing the appropriate overwintering method, you can ensure these beautiful plants survive the cold months and thrive again in spring. With a bit of patience and attention, your begonias will reward you with vibrant blooms and foliage year after year.
