Broad-leaf and small leaf privet are evergreen shrubs. Used in gardens, Privet has extensive environmental, agricultural and human health impacts.
Privet is considered to be a serious environmental weed throughout Australia.
Privet threatens the loss of native plants and animals by reducing habitat. Dense stands of privet prevent other vegetation from surviving or establishing.
Privet will produce masses of highly perfumed white flowers in mid to late spring aggravating hay fever and asthma sufferers and spreading seeds. It is thought that the perfume of Privet flowers causes allergic reactions ( e.g. asthma and hay fever).
How does it spread
Privet seeds are commonly spread by fruit-eating birds spreading the seeds into bushland and gardens but also through some nurseries still selling Privet and the dumping of garden waste containing seeds. Seeds can also be spread in flowing water.
Wide dispersal of seed by birds cannot be controlled hence controlling the spread of privet requires the removal of trees and seedlings before they produce seed. Privet regenerates vigorously from any remaining roots and stems and dumping of cuttings. Planting out areas after removing will limit Privet plants from regenerating.
It is critical to place all waste and cuttings in bags and red bins or taking to the rubbish tip.
For larger plants, the use of herbicides and replanting areas is the best long term control method. Water-dissolved chemicals can be sprayed directly on the leaves of young seedlings and groups of plants up to 3m high. Plants must be actively growing and complete coverage of the leaves is necessary.
Where Privet is dense and there are little or no other valuable especially native plants nearby then spraying is safe. However, for larger and older plants injecting stems and trunks with herbicide is most effective especially when amongst other vegetation. Every trunk or stem arising from the ground must be treated. The tree can be cut back (ideally not when flowering and not if the plant is likely to spill seeds) and herbicides (glyphosate) applied immediately to open area after cutting.
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