The wax begonia, known botanically as the Begonia semperflorens-cultorum group, is prized for its reliable performance and colorful display. It is characterized as a fibrous-rooted perennial, but in most temperate climates, it is grown as a warm-season annual for summer bedding and containers. These plants offer nearly continuous flowering from late spring until the first heavy frost, making them a fixture in garden beds and patio arrangements. Their versatility and ease of maintenance provide masses of color throughout the entire growing season.
Distinctive Features and Leaf Identification
Identifying a wax begonia is straightforward due to its uniquely textured and colored foliage, which gives the plant its common name. The leaves are glossy, succulent, and thick, possessing a waxy surface that helps the plant retain moisture. These ovate to rounded leaves are often slightly asymmetrical, or oblique, meaning the two sides of the leaf blade do not meet the petiole at the same point.
Leaf color is a primary identifier, as cultivars fall into two major categories: those with bright, medium-green foliage and those with deep bronze or reddish-brown leaves. The margins of the leaves are typically finely toothed or serrulate. Wax begonias exhibit a compact, bushy, and mounding growth habit, generally reaching a modest height of only 6 to 12 inches with a similar spread.
Optimal Growing Conditions and Maintenance
Light and Air Circulation
Managing light exposure depends on the cultivar and local climate. In cooler regions, plants tolerate full sun, which encourages a more profuse flowering display. In hotter climates, the plants perform best with partial shade to prevent leaf scorch and heat stress. Bronze-leaved varieties possess a greater tolerance for full sun compared to their green-leaved counterparts, which generally require more shade. If planted in locations that are too shady, the plants may become leggy and produce fewer blooms. Good air circulation is important, helping to minimize the risk of fungal issues like powdery mildew, particularly in humid environments.
Soil and Watering
The soil must be rich, moderately fertile, and well-draining to prevent root rot. Amending the planting site with compost or organic matter improves both fertility and drainage. Wax begonias prefer a slightly acidic soil pH, ideally ranging between 5.5 and 6.5, which supports optimal nutrient uptake. Watering should be consistent, aiming to keep the soil evenly moist throughout the growing season, especially when the plants are positioned in full sun. Allow the top layer of soil to dry slightly before watering again, avoiding saturated conditions. Once established, the waxy, succulent nature of the leaves allows these begonias to tolerate brief periods of moderate drought.
Feeding and Maintenance
To support the constant production of flowers, a regular feeding schedule is necessary during the active growth period. Apply a balanced, water-soluble fertilizer every four to six weeks, or a diluted application every two weeks, to replenish nutrients. Maintenance includes deadheading spent flower clusters, which encourages the plant to put energy into new blooms rather than seed production. Pinching the stems back occasionally helps maintain a compact shape and promotes a denser, bushier growth habit.
Methods for Multiplying Wax Begonias
Multiplying wax begonias is a simple process, accomplished through either stem cuttings or by starting them from seeds. The stem cutting method is the easiest way to produce clones of the parent plant.
Stem Cuttings
Select a healthy, non-flowering stem approximately three to four inches in length and make a clean cut just below a leaf node. Remove any leaves from the lower half of the cutting to prevent them from rotting. The cut end can be placed directly into a glass of water, where roots typically begin to form within two to four weeks. Alternatively, insert the cutting into a sterile, moist rooting medium like a mix of potting soil and perlite or vermiculite. Maintain the cuttings in a warm location with bright, indirect light until a strong root system has developed, at which point they can be safely transplanted.
Seed Propagation
Propagating wax begonias from seed requires starting them indoors six to eight weeks before the last expected frost date. The seeds are extremely small and should be sown using a fine, sterile seed-starting mix. Sow the seeds directly onto the surface of the moist medium without covering them, as they require light to germinate. A consistent temperature of 70 to 75 degrees Fahrenheit is optimal for germination, which usually occurs within one to three weeks. Maintaining high humidity by covering the tray with a clear dome or plastic wrap will aid this process. Once the tiny seedlings have grown large enough to handle and have developed their first true leaves, they can be carefully pricked out and potted into individual containers.