Begonias from tubers are a very rewarding plant. If protected from frost, they are a relative easy plant to grow. They can remain relatively pest free and provide a long flowering season.

You can start plants as early in February in a heated greenhouse or indoors on windowsill. The best temperature is 18-22 degrees. They will start growing at lower temperatures but their growth will be slower.

Keep moist, but, not standing in water or overly damp as this can lead to rot and mildew problems.

Plant the top of the tuber just below the soil surface, hollow side upward.

Which is the top of a Tuber?

You should be able to see where last year’s growth has been cut off. It is the concaved side (dish shaped). You may also see the first buds for new shoots.

When the first shoots appear, make sure the plant gets plenty of light and is rotated if on a windowsill to get a well rounded plant.

The begonias can grow quickly and so might outgrow their first 3 inch pot. Pot on to five or seven inch pots, before they are ready to be hardened off and planted outside.

Staking Begonias

Some upright begonias will need staking to tie in the leaves.

Growing Begonias Outside

Begonias will do well in most sunny spots. Ideally they prefer a bit of shade from mid day sun. However, if this is not possible, just keep well watered during dry spells. For best flowering displays, use a high potash (tomato) liquid feed. If fed, watered and dead headed they can offer a very long flowering season.

Storing Begonias

When foliage starts to yellow and die back in October, cut of foliage, lift from ground and dry in newspaper. Sprinkle some anti rot powder on the tuber and make sure they are stored in a dry, frost free environment. It is worth checking every month or so for any sign of rot. As soon as you spot a tuber with signs of rotting. Discard in refuse bin.

Related

• Tuberous Begonias
• Begonia Floral Show
  
  
• Begonias at Thompson & Morgan
• Tuberous Begonia at BBC