G’day, Nikolai here from The Lawn Firm. If you spot “dandelion-like” rosettes that keep coming back after mowing, you may have catsear (flatweed). I deal with it across Canberra every year. It spreads fast, sits low, and steals space from healthy turf. Here’s my clear plan that works.

What catsear looks like

Leaves: Hairy, lobed leaves in a flat rosette. Leaves feel rough compared with true dandelion.
Stems: Branched, hollow stems with multiple yellow flowers (dandelion has a single flower per stem).
Habit: Low, spreading rosettes that avoid mower blades.
Roots: Strong taproot that reshoots if you break it.

Why catsear thrives in Canberra

Thin turf leaves open soil and light for rosettes.
Compacted clay weakens grass and slows recovery.
Dry, hydrophobic spots create bare patches after summer.
Low mowing or scalping lets light hit the soil and triggers more seed.

When it is most active

Germination rises in autumn. Plants sit low through winter. Spring brings flowers and heavy seeding. I act before flowering so we shrink the seed bank.

How I tell catsear from dandelion

Flower stems: Catsear has many flower heads on branched stems; dandelion has one head per single stem.
Leaf feel: Catsear leaves are hairy; dandelion leaves are usually smooth.
Growth habit: Catsear hugs the ground and dodges the mower; dandelion sits a touch higher.

Prevention that works

Raise mowing height to shade the soil and protect the crown.
Seasonal fertilising to keep the lawn dense and competitive.
Core aeration in spring or autumn to open clay and drive roots down.
Wetting agent in warm months so water reaches the root zone.
Overseed + light top dress thin areas to close gaps before autumn germination.

Control once catsear appears

Hand removal (small numbers): Water first, then use a narrow weeding tool. Follow the taproot deep and lift the whole plant. Go slow. Bag and bin.
Targeted control (wider spread): Use a selective approach suited to broadleaf weeds on actively growing plants. Correct timing matters. Avoid blanket sprays on stressed turf.
Timing tip: Treat before or early in flowering to cut seed return.

Aftercare that stops the comeback

Rake out dead material so grass can move in.
Top dress 5–8 mm with fine sandy loam to level scars.
Overseed to rebuild density and block light to the soil.
Light feed to support steady recovery.
Deep watering, less often to train roots down and hold cover.

Common mistakes we fix

Snapping the taproot and leaving the base in the soil.
Scalping to “cut it out”, which weakens turf and invites more weeds.
Random spraying with the wrong type or timing.
Skipping aeration so compaction keeps grass weak.

My ACT timing guide

Late winter / early spring: Raise mowing height, feed, and remove early plants.
Spring: Aerate, overseed, top dress; control active rosettes before heavy seeding.
Summer: Maintain mowing height; use wetting agents; water deeply in the morning.
Autumn: Strengthen roots and close gaps before new germination.

DIY or call The Lawn Firm?

You can hand-weed a few rosettes and adjust mowing and watering. For lawn-wide outbreaks, timing and technique decide the result. I assess the site, apply the right control, and line up aeration, overseeding, top dressing, wetting agents, and seasonal feeding so catsear loses its foothold - and your grass keeps the space.