Overgrowth Management in Sassafras

Overgrowth Management in Sassafras: Local Conditions and What That Means for Your Property

Gully-side and rear boundaries in Sassafras are the most common source of overgrowth work. Properties that back onto the Sassafras Creek Nature Conservation Reserve corridor, or onto steep vegetated easements, have boundary vegetation that grows almost continuously given the rainfall and soil fertility. Blackberry (Rubus fruticosus agg.) is the primary problem species. It establishes in disturbed margins, runs along fence lines, and builds up into dense thorny masses that encroach on lawns and gardens within a single season if unchecked. English ivy (Hedera helix) is equally aggressive in Sassafras and is documented as killing tree ferns in gully areas; it climbs over cottage garden beds, smothers ground covers, and eventually climbs retained trees. Pittosporum undulatum (sweet pittosporum) is the third major overgrowth species. Research published on its invasion in the Dandenong Ranges shows rapid establishment in disturbed eucalypt forest margins, which is exactly the condition at the base of many Sassafras residential blocks where clearing or storm damage has opened the canopy. Left unmanaged, pittosporum forms a closed-canopy thicket that excludes all understorey. Overgrowth work here generally involves hand clearing, loppers, and reciprocating saw work rather than brushcutting alone, because the root mat under mature ivy or blackberry needs to be treated chemically to prevent regrowth. We use targeted stem injection and cut-stump herbicide methods in preference to broad foliar spray given proximity to creek corridors.