Begonias are a diverse group of ornamental plants popular for their vibrant flowers and striking foliage, used in both garden beds and containers. Whether they bloom all summer long is a qualified affirmative, heavily dependent on the specific type of begonia and the care it receives. Many modern cultivars are selectively bred to flower continuously from late spring until the first frost of autumn. Achieving this season-long display requires specific maintenance practices throughout the summer months.
How Begonia Variety Influences Bloom Duration
The longevity of a begonia’s flowering period is largely determined by its classification, as different types possess distinct biological characteristics. Fibrous or Wax Begonias, often sold as bedding annuals, are the most reliable for continuous summer color. These types are characterized as ever-blooming, producing flowers non-stop until cold weather arrives.
Tuberous Begonias grow from a tuber, a fleshy underground storage organ, and are known for their large, showy blooms. While they flower profusely and continuously from late spring through the fall, their life cycle includes a mandatory dormancy period. This rest is necessary for the plant’s survival and is triggered by the shortening days and cooling temperatures of autumn.
Rieger or Elatior Begonias are hybrids that combine traits from fibrous and tuberous types, resulting in dramatic, rose-like flowers on more upright stems. These are often grown as indoor houseplants due to their long, but not always “all summer,” bloom cycles. Rieger types prefer cooler temperatures and may struggle to maintain peak bloom performance during the hottest weeks of mid-summer.
Essential Maintenance for Sustained Summer Blooms
Achieving a season of uninterrupted flowering requires consistent attention to the plant’s light, moisture, and nutritional needs. One of the most important summer tasks is deadheading, which involves removing spent or fading blooms. This action prevents the plant from diverting energy into seed production, instead redirecting that energy toward creating new flower buds and encouraging continuous blooming.
Many begonia flowers, particularly the showier tuberous types, have pliable stems that allow gardeners to pinch or snap off the dead flowers. While some newer fibrous varieties are self-cleaning, most benefit significantly from regular manual removal. This practice also improves air circulation and reduces the risk of fungal diseases that can take hold on decaying plant material.
Begonia light requirements differ significantly by type and must be met to sustain bloom production. Tuberous begonias thrive in bright shade, receiving plenty of light while shielded from the harsh, direct rays of the afternoon sun that can scorch their leaves. In contrast, some fibrous types, such as wax begonias, are more tolerant and can handle partial sun conditions. They still benefit from some afternoon protection in warmer climates.
Consistent moisture is necessary, but overwatering is a common mistake that can lead to root rot. The soil should be kept evenly moist, but never soggy; allow the top inch or two of the soil to dry out completely before watering again. Begonias are heavy feeders, and regular fertilization fuels their prolonged flowering season. Applying a balanced liquid fertilizer with a high phosphorus content, such as a 15-30-15 formula, every two to four weeks provides the necessary nutrients to sustain vigorous flower production.
Preparing Begonias for the Dormant Season
For gardeners in non-tropical zones, preparing begonias for the dormant season is necessary to ensure their survival and rebloom the following year. Tuberous begonias cannot tolerate freezing temperatures and must be brought indoors before the first hard frost arrives. A light frost that blackens the foliage signals that the plants should be removed from the garden, allowing them to die back naturally in a frost-free environment.
The tubers should be allowed to cure, or dry out, for several weeks after the foliage has withered, before being lifted from the soil. After lifting, the tubers must be cleaned of excess soil and any remaining roots or stalks, as this organic material can promote rot during storage. The cleaned tubers are then stored in a dark, dry, and cool location, ideally between 40 to 50 degrees Fahrenheit. They should be packed in materials like dry peat moss, sawdust, or vermiculite.
Fibrous or wax begonias do not have a tuber and are typically treated as annuals, but they can be transitioned indoors to continue growing as houseplants. Before nighttime temperatures consistently drop below 50 degrees Fahrenheit, these plants should be moved to an indoor location with bright, indirect light. Watering should be reduced during the winter months, keeping the soil only slightly moist, as the plant’s growth naturally slows down.