Native To Australia
Boronia is a genus of 90-100 species of evergreen shrubs in the Rutaceae family. Native to Australia where it grows in open forests and woodlands, this non-hardy perennial can survive in California and other mild climates or can be grown in a cool greenhouse. It is difficult to cultivate since it requires excellent drainage and partial shade. For this reason, it is not suitable for subtropical or tropical climates. There are two well-known species of boronia: B.megastigma and B. heterophylla. B. megastigma is cultivated mainly in the southwestern tip of Australia and in Tanzania.
This small shrub rarely reaches 3 feet in height. The plant has aromatic leaves with small, bell-shaped flowers containing 4 petals. The exterior of the petal is a dark brown, while the interior is a bright yellow. When the flower is finished, the petals close to form a bud and the fruit ripens inside it. B. megastigma are known for their potent aroma similar to freesia or osmanthus: one plant in bloom will scent an entire greenhouse. Today, B. megastigma is grown on plantations, mainly in Tanzania, exclusively for its fragrance and flavor use. The flowers are collected, extracted with petroleum ether and concentrated, then re-extracted with alcohol to make an absolute. Boronia absolute is a dark green, semi-fluid liquid with a fruity odor. It is used in perfumes with bases of honeysuckle, violet and mimosa and added to fruit flavors to add body. Boronia essence is thought to help calm the mind from obsessive thoughts and difficult situations and it has been known to heal herpes virus lesions.
Growing Recommendations - Boronia
The boronia species most produced for both domestic and export cut flowers is B. heterophylla. Grown in SE and SW Australia, these shrubs can reach 6 feet in height. They have long, wiry stems with small, cup-shaped bright pink or purple flowers. B. heterophylla is more attractive than B. megastigma and its lemony fragrance is more appealing. The vase life of the cut stems is 5-7 days.