25 June 2026 · 7 min read
Sir Walter Buffalo winter care: keep it green through the cold months
A month-by-month winter guide for Australian Sir Walter Buffalo lawns — mowing, watering, frost protection, and weed control.
If you have a Sir Walter Buffalo lawn in southern Australia and the weather has just turned cold, you have probably noticed the colour fading and growth slowing right down. Good news: that is completely normal. Sir Walter does not die in winter — it just goes into a kind of half-sleep called semi-dormancy. The trick is knowing what to do, what to skip, and what will actually wreck your lawn if you do it at the wrong time. This guide walks you through it month by month for southern AU and NZ winters.
What Sir Walter does in winter
Sir Walter is a warm-weather grass. Once the soil cools below about 15°C, it slows right down. Growth almost stops. The colour fades from deep green to a paler, slightly yellowish green. In colder spots like Canberra, Hobart, or southern NSW it can show a bronze or purplish tinge after frost.
This is called semi-dormancy — a sleeping phase where the grass slows down to survive the cold. It is not damage. The lawn bounces back fully in spring.
The big idea: in winter, Sir Walter does not need help to grow. It needs help to not die. Most winter lawn problems come from doing too much, not too little.
What NOT to do in winter
These four mistakes ruin more Sir Walter lawns over winter than the weather does.
Do not spread nitrogen fertiliser
Nitrogen forces soft new growth. Soft new growth dies the next frost. You will burn the lawn worse than if you had done nothing. Stop nitrogen feeding from late autumn (around May in southern AU) until spring (around September).
Do not mow too low
A scalped Buffalo in winter has no leaves to catch what little sun there is. It also exposes the crown (the base of the grass plant) to frost. Both can kill patches outright. Raise the mower at least one setting going into winter.
Do not water frosty grass
Walking on a frosty lawn or hitting it with a sprinkler bursts the ice crystals inside each leaf and crushes the cells. The patches turn brown or purple by lunchtime. Wait until the frost has melted before doing anything.
Do not spray weed killer in cold weather
Most lawn weed killers need the lawn to be actively growing to work. In cold weather, the spray sits on the leaves and does little — except sometimes hurt the Buffalo. Wait for warmer spells or pull weeds by hand.
What TO do in winter
Raise the mower
Move your mower up to setting 5 or 6 of 7 (about 50–70mm, or two finger-widths tall). The longer leaves do three jobs:
- Catch more weak winter sunlight
- Shade the crown so frost cannot reach it as easily
- Out-compete winter weeds like winter grass and bindii seedlings
Only mow if the lawn looks longer. With Sir Walter, that might be once every 3–4 weeks in winter, not weekly.
Cut back the watering
In southern AU winters there is usually enough rain to do the job. Water deeply once a fortnight only if there has been a long dry spell. Skip watering completely after a frost or when more frost is forecast — wet grass freezes harder.
When you do water, do it before 9am so the leaves dry off during the day. Wet leaves overnight invite fungal disease.
Use iron for colour, not nitrogen
If the lawn looks too pale and you want a colour boost without forcing growth, spread an iron product instead of fertiliser. Iron gives Sir Walter a deep green colour within a few days without pushing soft growth that frost will kill.
The standout product here is Munns Professional Iron Boost from Bunnings. Spread it with a hand spreader and water it in. Watch your shoes and paving though — iron stains concrete brown.
Iron tip: apply on a mild morning when no frost is forecast for 24 hours, and water it in well. You will see the colour pop within a week.
Hand-pull weeds instead of spraying
Winter weeds like bindii, clover, and dandelion start small in late autumn and get tougher to remove the longer you wait. Pull them by hand on a warm day after rain — the soil is soft and the whole taproot comes out. Weed killers do not work well in the cold and most are risky on Buffalo anyway.
For sprayed weed control on Buffalo, wait for a warmer spell (a few days above 18°C) and use only Buffalo-safe products like Amgrow Bin-Die or David Grays Buffalo Master. Never use a regular lawn weed killer on Buffalo — it will damage the lawn.
Month-by-month winter plan (southern AU and NZ)
This is calibrated for Melbourne, Adelaide, Canberra, southern Sydney, Hobart, Auckland, and Christchurch. Tropical and subtropical regions (Brisbane, northern NSW, Northland) need less of this — Sir Walter barely slows down there.
| Month | Mowing | Watering | Feed | Weeds |
|---|---|---|---|---|
| May (early winter) | Raise to setting 5–6. Final mow before growth stops. | Cut back to once a fortnight | Last light feed of the season — use iron, not nitrogen | Pull winter weeds by hand while soil is soft |
| June | Mow only if longer than 60mm — likely not | Skip unless dry for 3+ weeks | None | Hand-pull only |
| July | Mow only if longer | Skip — rain handles it | None | Hand-pull only |
| August (late winter) | First mow back up if growth restarts | Once if dry for 3+ weeks | Light iron application for spring colour boost | Pull anything before it seeds |
Frost damage — what to do if it happens
If you wake up to brown or purplish patches the morning after a frosty night, do not panic. The damage is usually cosmetic on Sir Walter — the crowns are protected as long as you kept the lawn long.
Steps:
- Leave it alone. Do not mow or walk on it until the frost has melted and the lawn has dried (usually mid-morning).
- Skip the fertiliser. Nitrogen will not bring it back — it will just force soft growth for the next frost.
- Spread iron like Munns Iron Boost for safe colour on a mild day.
- Wait for spring. Most frost-damaged Sir Walter grows out completely in September and October.
If patches are still brown by mid-spring, then you can re-seed or plug in a small piece of fresh turf.
Shade and overhanging trees
In winter, shaded areas of Sir Walter take a bigger hit than sunny areas because they get even less weak winter sun. If you have a tree, prune the lower branches in autumn (March or April) so more light reaches the lawn through winter. That single job often saves a shady patch from thinning out.
Common winter mistakes
- Mowing too low because you want it to look tidy. Resist. Long is good.
- Spreading nitrogen because the colour faded. Use iron instead.
- Walking on frosty grass to grab the bin. The footprints will brown out by lunchtime.
- Spraying weed killer on a cold day. It will not work and may damage Buffalo. Pull by hand.
- Watering daily out of habit. Winter rain does the job.
- Panicking about colour fade. Sir Walter is supposed to fade a bit. Full green returns in spring.
Spring recovery — what to expect
When daytime temperatures consistently sit above 18°C (usually late September in southern AU), Sir Walter wakes back up. You will see:
- Colour returning over 2–3 weeks
- Growth restarting — first mow of the season usually mid-October
- Any frost-damaged tips growing out
That is the time to spread a proper spring fertiliser like Lawn Solutions Premium or Scotts Lawn Builder Buffalo. Not before.
How Lawnova handles winter Sir Walter care
Lawnova adjusts your task list based on your region and the actual weather forecast. So if a frost is coming, we delay your watering job. If a warm spell shows up in late winter, we suggest a light iron feed. The lawn gets exactly what it needs, when it needs it.
Sign up here and let us handle the timing for you.
Happy wintering.