Wax begonias (Begonia semperflorens Link et Otto) arrived to Berlin botanical garden from Brazil in 1821. They were propagated from seed and cultivated in parterre borders. They endeared themselves to the gardeners with their non-stop flowering. In warmer climates they truly are ever-flowering.
The first pink wax begonia was selected by the German gardener Russel in 1879. A year later the white flowering Schmidt’s begonia was introduced from Brazil. And since then, the spectacular hybrids of Schmidt and wax begonias have become the mainstay of gardens all around the world. In Lithuania these annuals have been named ‘lollipops’.
Many connoisseurs and hybridizers of wax begonias are based in Denmark and France, where these plants are especially popular. Currently there are listed more than 600 cultivars of wax begonias, which are divided into two groups: typical wax begonias with large, glossy, green or brown leaves and thick stems; and Gracilis group begonias with small, slightly drooping leaves, soft stems and larger flowers.
Leaves of these begonias are usually green, sometimes with a contrasting margin, or brown (at times muddy green). According to their height, wax begonias fall into 3 groups: tall (26-35cm), medium (21-25cm) and low (8-20cm) growing. Flowers come in a variety of colours, ranging from white to dark red, yellow being the only exception.
Wax begonias prefer being grown in full sun, or else they become straggly if planted in shade. Cultivate them on light, fertile, slightly acidic soil (pH 6.2). They do not perform well in alkaline conditions, where their growth is poor, and they become vulnerable to chlorosis and pests. The soil should be cultivated to the depth of 15-20 cm, since these plants have dense, although shallow, roots.
Poor soil should be enriched with peat, compost, well-rotted manure or leaf mold (20-25 kg per sq.m.). Heavy soil should be amended with sand (2-3 kg per sq.m.). Apply mineral fertilizers prior to cultivating the soil – 100-200 g of ammonium nitrate, 250 g of superphosphate and 100g of potassium salt per square metre, or alternatively use complete fertilizer in quantities as recommended on the package. When planting wax begonias in window boxes, use fertile universal planting mix. Since begonias respond well to the microelements boron and manganese, dissolve 2g of boron and 1g of potash permanganate in 10 l of water, and use this solution to water plants occasionally.
Wax begonias are usually planted outside or into containers in late May or early June, after all danger of frosts has past. Wax begonias should be planted in a way that their root necks are flush with the surface. Begonias are best planted in borders in 2 or 3 rows. The rows should be spaced at 13-15cm, with 10cm intervals between the plants. In island beds begonias look best when planted in groups. Tall plants should be spaced at 10-12cm, while 8-10cm is sufficient between the low – growing plants.
Water begonias with tepid water in the morning or in the evening. Mulch plants with peat to help conserve moisture within the ground. Feed begonias every 10 days with mineral fertilizers compounded for flowering plants.
Before the first frosts wax begonias can be transplanted into pots and moved inside. They will sulk for a couple of days, and may drop a few flowers, but later they will pick up and continue flowering for a long time. They can be grown as house plants – when fertilized continuously (a spoonful of fertliser to 10 l of water) wax begonias carry on flowering year-round, if only getting a little straggly in winter, when short of light. Begonias are transplanted in March or April, and their leggy shoots are shortened at the same time.
© Giedra Bartas, 2010