A team effort to keep them under control
Our site was abandoned for many years before it was considered as a possible location for garden around 2006. Before that, it was an industrial site. This allowed a nasty group of environmental weeds to get established but also allowed some remnant native flora to survive as well.
Since we took over the site, a lot of work and research has been done. A major study into our weeds in 2014 by Environmental Scientist Peter Austin, guided weed control for some time.
Changes to garden usage and other factors have seen a move away from some recommendations (glyphosate only used as a last resort rather than as a matter of choice, and using persistent materials like carpet under mulch is no longer done outside of individual plots).
The areas worked the most (the communal and individual plots) have been cleaned up the best, but still suffer encroachment through either rhizome spread or seed.
The quarry area and to the west of this were the last areas tamed. Getting on top of the area was made possible when a ride-on mower largely replaced the use of hand mowers around 2017, and some further landscaping was done in 2019.
The quarry area still under development, but with a lot of the weed seed bank
Our weed control strategy
Weed control was, and continues to be a community effort requiring a lot of time and effort.
Our main approach to weed control at is physical removal, then depending on the weed either composting (plant material) or removal from the site (wicked weeds information below) via FOGO bins. Heavily diseased plant material should also go into the FOGO bins.
Organic weed sprays may be used by the site manager or at their direction to control rhizomous grass (kikuyu and couch in particular) encroachment across long sections of garden borders.
Non organic sprays such as those based on glyphosate (Roundup) are used only in the most limited circumstances, and even then only with specific committee endorsement. Even if endorsed for a particular purpose, if anywhere near food crops this will only be applied by painting not spraying.
As a general rule, we compost most plant material, including weeds that are not designated as wicked weeds.
Bins around the garden to help members transport weeds. Do not mix normal materials and wicked weeds in these bins.
Members are expected to empty bins into compost bays at the end of each gardening session.
Wicked weeds are to be placed in FOGO bins at the end of each gardening session.
Our composting method is cold composting which will NOT kill seeds or extremely hardy rhizomes. We don't hot compost because we don't accumulate sufficient brown matter in a short enough period of time to make this possible.
Members are expected to keep pathways adjoining their plots weed free as well as their plot. Work with your neighbours on this. The same expectation applies to the various communal gardening groups.
Agriculture Victoria Resources Online has a range of information about other weeds and their distribution.
These weeds are invasive, spread easily and can out compete other plants - they are the enemies of a productive and prosperous garden.
We ask anyone who spots a wicked weed to physically remove it and put it in the FOGO bin(with the green lid) as our compost isn't hot enough to destroy its seeds and rhizomes.
ENEMY NUMBER 1
Pampas Lily-of-the-Valley - Salpichroa origanifolia
Unfortunately our site hits all of its favourite conditions - alkaline sandy soil and not too wet. This plant will kill plants the size of our sheoaks by smothering them if left to run.
In 2019, it started being seen in garden beds after a break of a few years. It needs to be eradicated completely by plot holders and community gardening groups if they find it in plots or other places on our site.
When physically removed, all parts of the plant must go into the FOGO bin.
Kikuyu is the grass that makes up most of our lawns. It was on the site before we took possession, and as a lawn works well.
However it is not an organism that respects boundaries in any way and will almost always find a way to go over, under or through. Luckily it is easy to remove from non-compacted soil, especially if biomass has not been allowed to build up.
When physically removed, all parts of the plant must go into the FOGO bin, since it will re-grow from just a small piece of rhizome.
The same comments are applicable to kikuyu's skinnier cousin, couch grass. Essentially any grassy plant that grows from a rhizome needs to be kept out of your plot and adjoining paths.
ENEMY NUMBER 3
Blackberry - Rubus spp.
Blackberry is more of an issue in the quarry and other little-used areas of the site, but still makes appearances in garden beds occasionally. This is probably from bird droppings.
As with most bramble berries, blackberry will grow from a relatively small section of cane. Any pieces of plant or root need to be placed in a FOGO bin.