African Olive

Olea europaea ssp. cuspidata

Family: Oleaceae

Type of weed:

Flower colour(s):

Priority Weed Regional Priority Weed. (See more weeds of the class.)

Flowering Months: , ,

Description

African Olive is an evergreen tree usually to heights and widths of 5–10 m. Bark is pale to dark grey developing a rough texture with age.

The upper surface of the leaves is glossy grey green and the underside is silver, green to brown with a hooked tip.

White flowers appear in spring on branchlets in leaf axils (where leaves join the stem).

Fruit is oval shaped, initially green maturing over autumn and winter to purple or black. African Olive produces thousands of seeds.

Don’t confuse with…

This weed can be confused with the native Mock Olive (Notelaea longifolia).

Dispersal

Seed is dispersed by birds and foxes.

Impact on bushland

If not controlled the plant will take over large areas forming huge, dense monocultures of African Olive. It is considered an ecosystem transformer.

Distribution

. From Mid Mountains (Woodford, Hazelbrook, Faulconbridge) to Lapstone and on the Cumberland Plains.

Alternative planting

Native plants

Local provenance:

  • Grevillea spp.
  • Banksia spp.
  • Hakea spp.

Council provides a tool, on its Mountain Landscapes website, to help you choose native alternative plantings. Choose your village, soil, vegetation community and the purpose of your planting, and the tool will give you suggestions.

There are native nurseries in several Blue Mountains villages, including Glenbrook, Lawson and Katoomba. Please also ask at your favourite local nursery.

Control

  • Hand remove
  • Stem inject or frill
  • Cut and paint

Hand remove

Grasp stem at ground level. Rock weed backwards and forwards to loosen roots, then pull out gently. Carefully tap the roots to dislodge attached soil. Replace disturbed soil and pat down.

Considerations

  • Leave weeds so that roots do not make contact with soil; on a rock, for instance. A small amount of debris may be hung in a tree or removed from the site.
  • Vary the position of your body to avoid fatigue when removing plants by hand over extended periods.

Cut and paint

Applying poison to cut stump from squeeze bottle
Apply poison immediately after cutting

Useful for small to medium sized woody weeds up to 10 cm in diameter.

Make a horizontal cut as close to the ground as possible with secateurs or loppers, and immediately apply concentrated Glyphosate to the exposed stump surface. Do not allow the surface to get covered with soil.

Herbicides that may be used to treat this weed include Array

Stem injection or frilling

Stem injection

Drilling holes at 45° and squirting poison into holes
Apply poison immediately after drilling

At the base of the tree, drill holes at a 45° angle into the sapwood (just under the outer bark) at two finger space intervals around the entire base of the tree. Repeat this process below the lowest branch

Frilling

As an alternative to drilling, make cuts into the sapwood with a chisel or axe. Fill each cut/hole with herbicide immediately. Repeat the process at 3 cm intervals around the tree.

Considerations

Plants should be healthy and actively growing. Deciduous plants should be treated in spring and autumn when leaves are fully formed. For multi-stemmed plants, inject or chip below the lowest branch or treat each stem individually. Herbicide must be injected immediately before the plant cells close (within 30 seconds before translocation of herbicide ceases.)

Herbicides that may be used to treat this weed include Array

Specific control tips for this weed

  • Seedlings can be hand pulled, ensuring all the roots are removed.
  • More established plants will need to be cut and painted.
  • Larger plants can be stem injected. The wood of African Olives is very hard, so ensure drilling or chiseling gets well into the stem.

Because the berries are spread by birds, it is best to treat plants before they fruit. Alternatively, dispose of the fruit. Other parts of the plant can be spread out off the ground. Once the material is dead it will decompose in place.

For key points on these techniques:

Regional Priority Weed

Control measures:

  • The plant should be eradicated from the land, which must be kept free of the plant.
  • The plant should be fully and continuously suppressed and destroyed.

For more info

For key points on these techniques: