This is part 6 of The Garden Guide — the studio's field manual for building a native garden from bare ground in Canberra and the Southern Tablelands. Start at the overview if you've just arrived.
The woody weeds get removed. Ground weeds are a different register: some you battle, and some you should leave alone entirely.
Problem ground weeds
- Ivy — wear a dust mask; the powder causes reactions in some people. If it's up a tree, cut all the way around the trunk to start killing it, then pull it down while it's still alive. Once dried out it goes brittle and snaps off high, and you'll never get it clean.
- Vinca / periwinkle — forks out easily enough.
- Couch grass — the arch-enemy. See below.
- Jasmine — smells beautiful, gets into everything. Five trumpet-shaped petals, pinky-red buds, leaves opposite on the branch.
- Potato vine — like jasmine but no scent and no red buds. Yellow centre.
- Wisteria — beautiful and strong enough to destroy timber structures. It will grow under a house and out the other side. It strangles trees you want.
- Passionfruit rootstock — Canberra winters kill the grafted top; the rootstock survives and becomes a rampant weed. Get on it early.
Couch grass — the mistake everyone makes
People weed it once, thoroughly, and expect it to be gone. It won't be. Expect to be pulling couch for at least a year — not intensely for a year, maybe intensely for a month, but it keeps coming back. The mistake is doing one good pass and then moving to another area.
Keep your attention on the patch. Every new shoot, pull it the moment you see it, roots and all. It takes seconds when it's small. Leave it a month or two and it's spread, and you're back to the start.
The runner is the plant. Every node will strike. Leave one and you have not removed it.
Minor ground weeds — mostly leave them
Grass weeds, violets, sticky weed, dandelions. If they're not dominating the garden or suffocating something you want, leave them.
- Dandelions — actively good. They decompact soil. Leave them.
- Violets — add nitrogen to the soil and make it available to other plants.
- Grass weeds — annoying, low risk.
- Sticky weed — the one to stay on top of; it climbs over everything.
If you're planting a dense understorey, you'll still want these out — they'll compete with small plants. But don't lose sleep over them. The weeds above are enemies. These are nuisances.
Resetting a whole area
When you want to clear everything and start again:
- Whippersnipper or mow it all as low as you can get it, and leave the green stems where they fall — they break down and feed the soil biology.
- One to two layers of thick cardboard over the top, always overlapping.
- 10–15cm of coarse forest litter or arborist chip on top. Ring around and ask an arborist to drop you a load — it's great material once mulched.
- Leave it six to twelve months.
You can plant into it sooner, but every hole you dig is an opening for weeds to come through, and weeding them out damages the plant you just put in.
One option if you're keen to get started right away: hand-weed the section you want to begin with now, and let the smother do the rest of the site for later. That way one area is underway while another is quietly being prepared for you.
What to keep
Some plants you'll know you want. Take those off the chopping block immediately. For everything in between, the questions: Does it go with the palette you've chosen? Have you seen small birds using it? Do lots of bees visit it? Do you like it? Does it smell good, or bad?
This series comes from the Garden Guide I give my design clients. I write one letter a week on spatial design, craft and technology — and subscribers read the full guides first.
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