Propagation
Sow seed when ripe in trays and prick out and pot up when they are large enough to handle. 
Division of the clump during spring and reduce the foliage.

Botanic information
Leaf: The lower leaves are narrow-lanceolate to oblong and the larger upper sessile leaves are lanceolate. The apex is acuminate and the margins are coarsely serrulate. The underside has a rough texture and the upper side is slightly concave from the prominent mid rib. They are arranged oppositely along the squarish stems.

Flower: The white expanded funnelform flowers have 5-green sepals and 5-petals that are deeply notched almost to the middle with 10-stamens with yellow-orange anthers and 3-styles. They are arranged in a loose cyme and appear from late spring to early summer.

Fruit: The dehiscent capsule has 6-8 valves and contains numerous small seeds. The seeds are viable but the plant may be reproduced vegetatively.