Commercially, plants of B. heterophylla and B. megastigma usually last five to eight years. Boronia heterophylla and B. megastigma stems for cutflowers are harvested when most buds are partially open, and at least 50 per cent are in full bloom. Immature flower buds will not open after harvest. B. megastigma flowers for oil are combed off by hand or with mechanical harvesters. For hand harvesting, the comb is drawn carefully through the bushes when the flowers are mature in September and October.
Opinions vary as to the best time of day to harvest the flowers.
Some growers prefer late afternoon, while others prefer early morning when the flowers are less sticky and easier to remove. The harvested flowers are placed in drums containing a solvent provided by the marketing companies. Care should be taken when dealing with solvents as they can be highly flammable. Discuss the harvesting operation and requirements with a suitable processing company well in advance of harvest. There are no clear guidelines on pruning boronia.