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Growing and Caring for Begonias
Introduction
Begonias are beautiful plants that add a splash of color to any garden or home. They come in a wide variety of shapes, sizes, and colors, and can be grown in pots, hanging baskets, or in the ground. With proper care, begonias can thrive and provide enjoyment for many years.
Types of Begonias
There are three main types of begonias:
- Tuberous begonias: These begonias are grown from tubers, which are fleshy underground stems. They have large, showy flowers in bright shades of pink, yellow, orange, red, and white. Tuberous begonias are ideal for growing in pots and hanging baskets.
- Fibrous-rooted begonias: These begonias have a typical root ball of thin, fibrous roots. They include the dwarf bedding types, known as wax begonias, and tend to have smaller leaves and flowers. Fibrous-rooted begonias can be grown in containers, window boxes, or as bedding at the front of a shady border.
- Foliage begonias: These begonias are grown for their spectacular leaves, which come in a range of shapes, colors, and patterns. They include the cane types (with upright stems that have different segments, like a bamboo cane) and the Rex begonias (with large, silver and green leaves). Foliage begonias are popular as house plants but can also be grown outdoors in summer.
Planting Begonias
- When to plant: Begonias should be planted outdoors after the last frost date. In most areas, this is around May.
- Where to plant: Begonias prefer to grow in dappled or partial shade. Avoid planting them in south-facing spots, as the foliage can burn in direct sunlight.
- How to plant: When planting tuberous begonias, plant the tubers hollow side up, 2.5 cm deep in peat-free, multi-purpose compost. Keep the compost moist and place the pots in a warm spot that is at least 18 degrees Celsius. Once the leaves begin to show, pot on into larger pots. Other begonia types can be bought as pot-grown plants or plugs. Grow them in a greenhouse and harden off after all risk of frost has passed before planting outdoors.
Caring for Begonias
- Watering: Begonias need to be watered regularly, but allow the soil to dry out between waterings. This is especially important for tuberous begonias, which can rot in waterlogged soil.
- Fertilizing: Feed pot-grown begonias every week or so in summer with tomato feed, or add a slow-release fertiliser pellet to the compost when planting. Stop feeding from September as plants should be encouraged to slow down for the year.
- Overwintering: Tuberous begonias should be lifted from their pots after the first light frost and before it gets any colder. Remove the compost from each tuber, cut the stem back to about 6 cm, and store in a dark, cool, frost-free place until March, when they can be brought back into growth again. Fibrous-rooted begonias can be dug up and composted when they’ve finished flowering, or overwintered somewhere frost free.
Propagating Begonias
- Tuberous begonias: Tuberous begonias can be propagated via cuttings. In March or April, pull new shoots that form on the tubers away with your fingers. Pot them up into individual pots and put them in a heated propagator.
- Fibrous-rooted begonias: Fibrous-rooted begonias can be grown from seed in early spring. Sow seeds onto moist seed or multi-purpose compost. They need some light to germinate, so don’t cover them.
- Foliage begonias: Foliage begonias can be propagated by leaf cuttings or division.
Pests and Diseases
- Powdery mildew: Powdery mildew can be a problem for begonias, especially for yellow-flowering types. This fungal disease spreads by spores, so good hygiene should reduce the chances of attack. To prevent the problem, space plants out well and ventilate greenhouses.
- Vine weevil: Vine weevil can be a problem with pot-grown begonias.
Best Begonia Varieties
Some of the best begonia varieties to try include:
- Begonia Inferno: A tuberous begonia that provides months of bright orange, weather-resistant flowers.
- Begonia Giant Picotee Mixed: A tender perennial with serrated leaves and large ruffled pink, apricot, or yellow flowers.
- Begonia Illumination Series: Cascading flowers in bright colors, weather-resistant flowers. Ideal for a hanging basket.
- Begonia semperflorens: Tender perennials grown as annuals. Small plants with fibrous roots ideal for summer bedding displays.
- Begonia rex: Grown for its large silver and green foliage that has a rusty brown underside. Tender so needs to be grown as a house plant.
- Begonia luxurians: The palm-leaf begonia. It can be grown as an impressive house plant in a shaded conservatory, and can be put outside in the summer.
