Welcome to my website where I gather information about plant pests and pathogens preying on gardens in my local area in Melbourne. I want to live in harmoney with nature and so I use exclusion techniques and natural predators to protect my edible and ornamental plants instead of using poisonous chemicals...................John Ashworth 27th July 2015.
Latest Update 5th October 2016. Oxalis.
Binomial name: Oxalis pes-caprae.
Oxalis or wood sorrel, is a beautiful flowering plant with clover shaped leaves. It was introduced into Australia as an ornamental plant, but is now regarded as a hard to remove weed.
This winter's wet weather has favoured the weed and it has taken hold of large tracts of woodland and roadside "nature strip"particularly in the bush beyond Melbourne's Northern and Western suburbs.
It is a long-lived herbaceous perennial growing from underground bulbs.
It produces a rosette of leaves at ground level and 150-300 mm tall flowering stems
Its leaves are formed on the ends of 100-200 mm long stalks with three heart-shaped leaflets looking a bit like clover leaves.
It has loose clusters of bright yellow flowers each having five petals which open only during sunny periods and close again at night or during dull periods during the day.
It propagates from seed and from bulbils which are formed on the plant's roots. Its very difficult to control, since these bulbils break off and form new plants if you pull the parent out of the ground.
They are a bit of a pest in my new lawn, but I pull them out as soon as I see them, trying to weaken them before the bulbils are fully formed.
Why Oxalis is a Pest.
They are very invasive and will occupy every square centimeter of bare soil if not controlled.
Organic Pest Control.
I use mulch to smother them and remove flowering heads as soon as they appear so they can't propagate by seed.
If I have a patch of them big enough, I use weedmat to smother them, by denying them access to the sun for photosynthasis.