Begonia Elatior Rebloom — Getting Rieger Begonias to Flower Again

How to get Rieger (Elatior) begonias to rebloom after purchase. These spectacular tuberous hybrids can flower repeatedly with proper light and temperature management. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Rieger begonias are short-day plants — they initiate flower buds when nights exceed 12 hours. Most people discard them after the first bloom, but they can rebloom multiple times. Light: Bright indirect during growth; short days (14 hours darkness) to trigger flowering. Temperature: Cool 60-70 F for best flowering; heat above 75 F causes leggy growth and fewer blooms. Bloom period: Fall through winter naturally, or any time if day length is manipulated. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Rieger begonias are complex hybrids of tuberous and wax begonias bred for spectacular indoor blooms. They are photoperiodic — requiring long nights (short days) to switch from vegetative to flowering mode. Without deliberate short-day treatment, they remain vegetative and never set flower buds. Commercial growers use blackout curtains to control day length — you can simulate this at home. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: After first bloom fades: cut back stems by half and let the plant grow in bright indirect light all summer. Feed every 2 weeks with balanced fertilizer during the summer growth period to build energy. In early September: begin short-day treatment — 14 hours of uninterrupted darkness per night for 6-8 weeks. Use a closet or cover with a box from 6 PM to 8 AM — even brief light interruption resets the process. After 6-8 weeks of short days: buds appear. Resume normal light and care — flowers open in 2-4 weeks. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Flowering Plants collection on Houseplants Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.