The Friends of
Shenton Bushland
Inc.
How will we find our wild hearts inside this city;
How will we find the deep peace?
A. Stevens
Bushland Activities page (blog)
Bushland Management Strategies
Individual Management Strategies:
Management Strategy for Watsonia (Watsonia meriana)
Shenton Bushland currently has one large (approx 0.5ha) infestation of Watsonia near the south-west corner. This infestation involves bushland that is otherwise in good condition, so it is a priority to remove before it spreads out of control throughout the bushland.
Control Methods
Several control methods are being used:
(a) physical removal of bulbs during winter
(b) chemical control by wiping leaves with Glyphosate
(c) chemical control by spraying with Dalapon
(d) removal of flower heads
Physical removal is used for outlying plants around the edges of the infestation. The aim is to contain the infestation and remove Watsonia that are too close to other plants to be controlled chemically. Because the bulbs tend to be quite deep and often break off, physical removal is only 50% successful. This approach is used through winter as plants emerge. Large infestations are not pulled out - it is better to leave these for chemical treatment - the disturbance will foster more weed invasion.
Wiping with Glyphosate (mixed 1:10 water) using a sponge attached to a squeeze bottle has been trialled in the dense infestations, but a fire in 97/98 made it difficult to assess the success of this approach.
Wiping was performed by GreenCorps teams in 1999, 2000, and 2001. Results were poorer then expected.
In 2001 Kate Brown sprayed the chemical Dalapon on a number of trial plots. The Dalapon appeared to have a significant effect in reducing the number of Watsonia plants, while no dramatic impact was seen with native species. However, sedges are sensitive to Dalapon, so it must be used with great care.
Funding has been obtained for applying Dalapon in 2003.
Flower head removal is used in late spring when the soil is too dry to remove bulbs and it is too late to use chemical controls. The aim is to prevent spreading of Watsonia by seeds
Monitoring Methods
Six quadrats have been installed in the infested area to monitor impact.
These are scored each year (October).
Pulling bulbs at random through the infestation gives an indication of chemical control effectiveness. Large bulbs are an indication that the chemical control is not effective.
