Be Weed Wise - Ochna

Ochna, Mickey Mouse plant (Ochna serrulata)

Ochna is another example of an ornamental species escaping into bushland. A native of Africa, it has been widely planted in Australian gardens for its strikingly attractive flowers. It is a significant environmental weed in south-east QLD, eastern areas of NSW and Lord Howe Island.

Description

Ochna grows as a shrub that is erect and woody up to about 1.5 m high. Leaves are up to 5 cm long, narrow and glossy with serrated margins. New growth usually has a bronze tinge. Flowers are bright yellow.

The petals fall off, leaving the sepals which turn scarlet red when the fruits appear. Fruits are initially green, turning glossy black in summer. Root is an angled tap root that is easily broken when hand pulled, hence Ochna easily reshoots.

Dispersal

Ochna serrulata has invaded roadsides, disturbed sites, waste areas, rainforests, forest margins, riparian areas and dry sclerophyll forests. Seed is spread by water, animals (foxes and rabbits), birds and humans, in contaminated soil (earthmoving equipment, car tyres, etc.) and by dumping garden waste into bushland. Locally, Ochna is easily dispersed to new areas when birds eat the fruits and spread the seeds. It forms dense thickets that are hard to remove, and it competes with native plants.

Removal

For young seedlings hand pulling from down where the seedlings come out of the ground is generally the most successful method of control. Take care not to break the tap root. Larger individuals may need to be grubbed out with a mattock. 

Glyphosate can be used to remove Ochna using the Scrape and Paint method. Scrape all the stems at the base with a sharp knife and apply undiluted Glyphosate. Wait for the plant to defoliate and remove above ground parts.

Grow Me Instead

Native Fuschia (Correa species and cultivars)

There are many attractive species and cultivars of
the native Correa. Most tolerate drought and poor soils, although some of the larger species such as Correa lawrenceana typically grow in moist situations. All have bell-shaped flowers which attract honeyeaters.

Guinea flower (Hibbertia species)

With masses of bright yellow flowers, and easy to grow, several species of Hibbertia, e.g. Hibbertia empetrifolia, are commonly available from nurseries. Like most Australian native plants, they require good drainage.