Pre-Emergent and Post-Emergent Herbicide Timing Chart for Australian Turf

Name: Gilba Solutions Pty Ltd
Price range: $

This post emergent and pre-emergent timing chart covers 50+ Australian turf weed species. Updated April 2026.

A pre-emergent timing chart that shows when to apply post-emergent and pre-emergent herbicides to common Australian turf weeds, month by month. Orange cells mark the post-emergent window when weeds are actively growing and taking up herbicide. Blue cells mark the pre-emergent window, when herbicide must be applied before germination begins.

The original data comes from Clemson University HGIC 2334 (Smith & Gore), shifted six months for the Southern Hemisphere. Several windows have been adjusted based on field observations across NSW, VIC, and QLD. Timing will vary with latitude and seasonal conditions. For precision, monitor soil temperature at 50 mm depth rather than relying on calendar dates.

All products must hold current APVMA registration. Check at portal.apvma.gov.au before use.

How to Read This Chart

Post-emergent window

Pre-emergent window

Life Cycle Key SA = Summer Annual WA = Winter Annual B = Biennial WSP = Warm Season Perennial CSP = Cool Season Perennial

The chart is divided into three sections: grass weeds, broadleaf weeds, and sedges. Each row shows one weed species with its common and scientific name, life cycle classification, any special notes, and a 12-month calendar running from July to June (the Australian financial year, which aligns with the seasonal transition from winter dormancy through summer growth and back).

Grass Weed Timing

Weed	Latin Name	Life Cycle
Bahia Grass	Paspalum notatum	WSP
Barnyard Grass	Echinochloa crus-galli	SA
Common Couch Grass	Cynodon dactylon	WSP
Summer Grass / Crabgrass	Digitaria spp.	SA
Crowsfoot / Goosegrass	Eleusine indica	SA
Dallisgrass / Paspalum	Paspalum dilatatum	WSP
Panicum Grass	Panicum spp.	SA
Foxtail	Setaria spp.	WSP
Parramatta Grass	Sporobolus africanus	WSP
English Couch	Elymus repens	CSP
Ryegrass, Annual	Lolium rigidum	WA
Winter Grass / Poa annua	Poa annua	WA
Sand Burr / Hedgehog Grass	Cenchrus spp.	SA
African Lovegrass	Eragrostis curvula	WSP
Windmill Grass	Chloris truncata	SA
Guildford Grass	Romulea rosea	CSP

Broadleaf Weed Timing

Weed	Latin Name	Life Cycle	Notes
Bindweed	Convolvulus arvensis	WSP
Bittercress	Cardamine spp.	WA
Mexican Clover	Richardia brasiliensis	WSP	Requires 2+ applications
Capeweed	Arctotheca calendula	WA
Catsear / Flatweed	Hypochaeris radicata	CSP
Chickweed, Common	Stellaria media	WA
Chickweed, Mouse-ear	Cerastium spp.	CSP
Clover, White	Trifolium repens	CSP
Creeping Oxalis	Oxalis corniculata	WA/CSP
Cudweed	Gamochaeta spp.	WA/B
Dandelion	Taraxacum officinale	CSP
Dichondra	Dichondra repens	WSP
Dock, Broadleaf	Rumex obtusifolius	CSP
Dock, Curly	Rumex crispus	WSP/CSP
Dollar Weed / Pennywort	Hydrocotyle spp.	WSP
Fleabane	Conyza spp.	SA/WA
Geranium, Carolina	Geranium carolinianum	WA/B
Henbit	Lamium amplexicaule	WA
Bindii / Onehunga Weed	Soliva sessilis	WA
Knotweed, Prostrate	Polygonum aviculare	SA
Lambs Tongue / Plantain	Plantago lanceolata	CSP
Lespedeza	Kummerowia striata	SA
Medic, Black / Burr Medic	Medicago spp.	SA/B
Nettle, Dead / Purple	Lamium purpureum	WA
Onion Weed	Nothoscordum spp.	CSP	2 applications needed
Parsley Piert	Aphanes arvensis	WA
Pigweed	Amaranthus spp.	SA
Plantain, Broadleaf	Plantago major	WSP
Purslane, Common	Portulaca oleracea	SA
Smartweed	Persicaria spp.	SA
Sorrel, Red / Sheep	Rumex acetosella	CSP
Sowthistle	Sonchus oleraceus	WA
Spurge / Asthma Weed	Euphorbia spp.	SA
Ox-eye Daisy	Leucanthemum vulgare	CSP
Creeping Buttercup	Ranunculus repens	CSP
Khaki Weed	Alternanthera pungens	SA
Caltrop	Tribulus terrestris	SA
Birdseye Speedwell	Veronica persica	WA

Sedge and Other Weed Timing

Weed	Latin Name	Life Cycle	Notes
Mullumbimby Couch	Kyllinga brevifolia	WSP	2 applications needed
Nutgrass, Purple	Cyperus rotundus	WSP	2 applications needed
Nutgrass, Yellow	Cyperus esculentus	WSP	2 applications needed
Moss		-	Cultural control preferred

Application Safety Notes

Caution 1: Spring green-up on warm-season turf Do not spray post-emergent herbicides on warm-season grasses (couch, kikuyu, buffalo, zoysia) during spring green-up (typically Aug-Oct in Australia). The turf is coming out of dormancy and cannot metabolise foliar herbicide properly. You will get severe injury, slow recovery, and a thinner stand that lets more weeds in. Pre-emergent applications during this period are acceptable where label permits.

Caution 2: High temperatures on cool-season turf Do not spray when temperatures exceed 30°C, especially on cool-season turf (ryegrass, fescue, bentgrass). Surfactants cause serious burn under heat stress. If you must treat during a warm spell, spray late afternoon and let the product absorb overnight before the next day's heat.

Caution 3: Herbicide resistance Do not rely on the same active ingredient or mode of action group for consecutive applications. Rotate between mode of action groups to reduce selection pressure. If a weed population stops responding to a product that previously worked, suspect resistance and switch to a different mode of action. See the herbicide resistance chart for mode of action group classifications.

Source: Adapted from Clemson University HGIC 2334 (Smith & Gore). Timing shifted +6 months for Southern Hemisphere. Verify with local conditions and current APVMA registrations. View our turf chemicals range. Chart prepared by Gilba Solutions Pty Ltd.

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Download the printable version of this timing chart for your shed wall or spray cabinet.

Download Timing Chart (PNG)

Pre-Emergent and Post-Emergent Herbicide Timing Chart for Australian Turf

How to Read This Chart

Grass Weed Timing

Broadleaf Weed Timing

Sedge and Other Weed Timing

Application Safety Notes

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21 Thompson Street Bowral NSW 2576

CELL: 0499975819

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