Propagation
Take soft tip cuttings of non-flowering shoots during late spring to early summer.

Divide suckers during spring.

Botanic information
Leaf: The dull green leaves are broad ovate with an acuminate apex and a very pubescent short petiole. The margin is entire or sparsely serrated and ciliate. They are arranged in opposite pairs along the stems and turn yellowish in autumn before falling.

Flower: The campanulate flowers have 5-expanding pink petals with a yellow flushed throat and are arranged in a terminal corymb that is up to 80mm (3in) wide and appear from late spring to early summer. 

Fruit: The small  capsule has a bristly covering and is dehiscent and  contains a single small seed. The fruit is persistent on the plant during winter and the seeds are viable but the plant is commonly reproduced vegetatively.