Plant Guide: Begonnia

Tuberous begonias are the result of breeding and selection from various South American species, and many are grown by specialists for exhibition. Begonia tuberhybrida is the most widely cultivated type; the hybrid series ‘Non-stop’ is particularly popular because of its long flowering period. Begonias make excellent houseplants, but are also suitable for containers on patios or for planting outdoors in borders; trailing varieties are especially well suited to hanging baskets.

Flowers vary greatly in form: they may be single or double, camellia- or carnation-like, with some simple and others heavily ruffled. Blooms occur in groups of three, with the large central male flower being the most prominent; the smaller female flowers are usually removed once flowering begins. Colours include red, pink, yellow, cream and white, with some bi-coloured forms. Plants grow to a height of 25–45 cm (10–18 in).

GROWING CONDITIONS

Aspect
Begonias prefer filtered sunlight or light shade and shelter from strong winds.

Position
Grow plants indoors or in a greenhouse, or plant them outdoors in containers or beds once all risk of frost has passed. Soil should be rich and moisture-retentive without drying out; incorporate plenty of organic matter such as well-rotted compost.

CULTIVATION

Planting
Dormant tubers can be started in spring in pots of moist peat or compost by placing them hollow side up. Lightly mist the top of the tuber once and ensure the compost remains just moist. Potted plants with foliage are also available later in spring. Plant outside only when there is no risk of frost, spacing plants 23–30 cm (9–12 in) apart.

Feeding
During the growing season, apply a liquid feed every 14 days. Keep plants consistently moist, but avoid waterlogging.

Problems
Powdery mildew can be an issue, especially in warm, dry conditions. Improve air circulation around plants and use a suitable fungicide if necessary.

FLOWERING

Season
From early summer through to autumn.

Cutting
Flowers are not suitable for cutting.

AFTER FLOWERING

Care
Lift the tubers once the stems die back in autumn. Store them in dry peat or compost in a cool, frost-free place until the following spring.