A patchy, weed-strewn lawn is one of those things that sneaks up on you—one season it was fine, the next your neighbours have that uniform green carpet and you’re wondering what happened. The good news for NZ homeowners is that a single product can tackle both problems at once. Weed and feed combinations promise to kill broadleaf invaders while greening up the grass, and in New Zealand, Yates dominates the shelf space.

4 related posts

Popular Brand: Yates · Format: 4L Hose-On · Targets: Broadleaf Weeds · Added Nutrients: Nitrogen & Iron

Quick snapshot

1Confirmed facts
2What’s unclear
  • Exact best month varies by NZ region (north vs south island microclimates)
  • Long-term weed kill permanence not documented in Yates trials
  • Celsius temperature thresholds not specified for NZ conditions
3Timeline signal
4What’s next
  • Check local retailer stock at Mitre 10 or Bunnings before spring
  • Choose Hose-On for large areas or Granular for precise application
  • Monitor weed regrowth 6–8 weeks post-application for need for follow-up spot spray

The table below consolidates the key specifications for Yates Weed ‘n’ Feed based on the manufacturer’s official product documentation and retailer listings at Mitre 10 and Bunnings.

Key specifications for Yates Weed ‘n’ Feed products
Label Value
Controls Common broadleaf weeds
Format Hose-on 4L
Nutrients Nitrogen and iron
Retailers Mitre 10, Bunnings
Coverage (4L bottle) 260 square metres
Coverage (2L bottle) 130 square metres
Weed kill timeline Up to 3 weeks visible; 4 weeks for full eradication
Safe grass types Most lawn grasses except Buffalo grass
Annual applications Twice yearly (Spring and Autumn)

When to apply weed and feed in NZ?

Timing is the single biggest factor determining whether weed and feed delivers on its promise or wastes your money. Yates recommends applying their Weed ‘n’ Feed twice yearly—in Spring when the lawn is surging back to life, and in Autumn before the colder months set in.

Best months for application

  • Apply in early Spring when lawn grass shows active new growth and weeds are still young—before they flower and set seed, according to Yates NZ Official Product Page guidance
  • Autumn application (March through May in NZ) prepares the lawn for winter by promoting thicker, greener growth and giving weeds less room to establish
  • In the North Island, Spring applications often begin in September; in the South Island, October is typically safer due to later frost risk

Weather and soil conditions

  • Avoid applying in hot, dry conditions—Yates explicitly warns against use during summer heatwaves to prevent lawn damage
  • Ideal temperatures sit in the 60–90°F range for active growth, which broadly translates to mild, overcast days in the 15–25°C range
  • No rain for 24–72 hours after application is the general rule across most weed and feed products to allow absorption
  • Mow the lawn 2–4 days before treatment so weeds are actively growing and can take up the herbicide, per Lawn Love application guide for weed and feed
Bottom line: Spring and Autumn are the two fixed windows—mild temperatures and actively growing weeds are the conditions that make it work.

Do weed and feed really work?

The honest answer is yes—but with qualifications. Weed and feed works well on broadleaf weeds in an actively growing lawn applied at the right time. It does not kill all weed types (grassy weeds like paspalum are largely unaffected), and results take weeks rather than days.

How it kills weeds

  • Yates Weed ‘n’ Feed uses plant hormones (synthetic auxins) absorbed through weed leaves and transported to the roots, causing yellowing, leaf curl, and eventual death
  • The active ingredient targets broadleaf weeds specifically—these have different leaf structures than grass and are susceptible to hormone disruption
  • For NZ lawns, Onehunga weed, catsear, clover, daisy, chickweed, chamomile, dock, and thistle are all on the targeted list, as documented on Yates NZ Official Product Page

Lawn greening results

  • The fertiliser component adds nitrogen and iron, which produce visible greening within 1–2 weeks of application
  • Nutrients support grass recovery from weed competition and fill in bare patches left when weeds die off
  • The dual action—simultaneous weed kill and feeding—is the main selling point, though the fertiliser is relatively fast-release rather than slow
What to watch

Weed and feed delivers visible greening within weeks, but full weed control takes up to 4 weeks. Don’t reapply before this window closes—if weeds persist, spot-spray with a targeted herbicide instead.

What is the best weed killer for lawns in NZ?

For NZ homeowners, Yates Weed ‘n’ Feed is the dominant retail option and the one with the most locally-relevant documentation. But the “best” product depends on your lawn size, grass type, and whether you have nearby garden beds at risk of overspray.

Top products reviewed

  • Yates Weed ‘n’ Feed Hose-On: The flagship product—suitable for large areas, with coverage of 260 square metres from the 4L bottle
  • Yates Weed ‘n’ Feed Double Action Granular: Better for precise application or small lawns where hose pressure is inconsistent; avoids overspray risk
  • Watering can option: Dilute 300ml of concentrate in 9 litres of water for smaller lawns, per The Garden Gurus video demonstration of weed and feed dilution

Yates options

  • Yates Weed ‘n’ Feed Hose-On is safe on most NZ lawn grasses but should not be used on Buffalo grass, which is sensitive to the herbicide component
  • Companion product Yates Lawn Fertiliser Quarterly (12-week slow release) pairs well with Autumn applications to maintain nutrient supply without the fast-nitrogen surge
  • For prickly weeds like Onehunga, Yates Prickle Weedkiller may be needed as a supplementary spot treatment, particularly in Autumn and again before early spring
The trade-off

Weed and feed products deliver convenience—weed kill and feeding in one pass—but the fertiliser is a fast-release formulation. For gardeners seeking a slower, steadier nutrient supply, pairing a spot herbicide with Yates Lawn Fertiliser Quarterly is a better long-term strategy.

Is Weed and Feed Bad for Your Lawn?

Weed and feed is safe when used as directed and on appropriate grass types. Problems arise from overuse, application in the wrong conditions, or use on sensitive grass varieties.

Potential downsides

  • Fast-release nitrogen can cause a surge-and-crash greening effect—lawn looks great briefly then drops off if not followed by consistent watering
  • One NZ gardening forum user described weed and feed as “just a sugar hit for the weeds,” noting that products like Turfix or Turfclean Ultra offer more sustained results for some users
  • Over-applying can scorch grass due to salt build-up in the fertiliser component, as documented by Lawn Love blog covering weed and feed safety
  • Do not apply to newly laid lawns—wait until the grass has been mowed at least 3 times (roughly 2 months) before using any weed and feed product

Proper use tips

  • Use Hose-On at moderate pressure—full pressure can prevent the siphon mechanism from drawing product correctly, per Yates NZ official product demonstration video
  • Water the lawn thoroughly 24–48 hours before application if conditions are very dry, but avoid waterlogging
  • After granular application, water in well within 24 hours; for hose-on, allow product to dry on leaf surfaces before any rainfall
  • Avoid application before heavy rain predicted within 24 hours to prevent runoff and reduced efficacy
Bottom line: Weed and feed is not inherently bad for your lawn—but it rewards careful timing, correct dosage, and appropriate grass type matching.

What is the best month to put down weed and feed?

For NZ conditions, the “best month” is less fixed than the season. Spring application targets weeds before their summer peak; Autumn application sets the lawn up for winter dormancy. The window shifts slightly by region.

Spring vs autumn

  • Spring (September–November in NZ): ideal for maximum weed kill as weeds are actively growing and grass is recovering from winter dormancy
  • Autumn (March–May): focuses on feeding—building root reserves and grass density before cold weather reduces growth rates
  • Applying weed and feed in summer heat is the most common mistake—Yates explicitly advises against this to prevent lawn damage

NZ regional variations

  • Northland and upper North Island: earlier spring start possible from late August given warmer microclimates
  • South Island and high-altitude areas: delay Spring application until October to avoid late frost damage to stressed grass
  • Coastal vs inland areas: coastal areas may retain mild temperatures longer into Autumn, extending the application window

Upsides

  • Dual action: kills weeds and feeds grass simultaneously
  • Targets broadleaf weeds specific to NZ lawns (Onehunga, clover, daisy, thistle)
  • Convenient single-pass treatment saves time
  • Available at major retailers (Mitre 10, Bunnings)
  • Results visible within 2–3 weeks for greening; 4 weeks for full weed kill
  • Safe on most common NZ lawn grasses

Downsides

  • Not effective on grassy weeds (paspalum, twitch)
  • Fast-release nitrogen may cause short-term surge rather than sustained greening
  • Cannot be used on Buffalo grass
  • Results take weeks—not an immediate fix
  • Risk of scorch if over-applied or applied in hot conditions
  • Limited long-term permanence—follow-up applications typically needed

Application steps

Correct application technique is the difference between a product that works and one that disappoints. These steps apply to the Yates Weed ‘n’ Feed Hose-On format, the most common retail option in NZ.

  1. Mow 2–4 days before application so weeds are actively growing and can absorb the herbicide; do not apply immediately after mowing
  2. Check the weather forecast—no rain for 24–48 hours after application; mild temperatures (15–25°C) preferred; avoid windy days to prevent drift
  3. Attach the Hose-On bottle to your garden hose; apply at moderate pressure, moving steadily across the lawn in an even pattern
  4. Apply to 260 square metres with the 4L bottle (or 130 square metres with the 2L)—do not double-apply to the same area
  5. Allow product to dry on leaf surfaces for several hours before any irrigation or rainfall
  6. Water in granular products within 24 hours if using the granular format; for Hose-On, the water carrier serves this purpose
  7. Wait 4 weeks before assessing results—if weeds persist, spot-spray targeted herbicide rather than reapplying the full weed and feed
The upshot

Weed and feed works—Yates Weed ‘n’ Feed in particular is backed by a product page, official YouTube demonstrations from the manufacturer, and years of NZ garden forum discussion. The conditions that make it work are straightforward: the right season, actively growing weeds, and patience while it does its job over several weeks.

Related reading: New Zealand seasons · Nelson, New Zealand guide

Additional sources

youtube.com, lawnstarter.com, yates.co.nz, lawnlove.com, youtube.com

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Frequently asked questions

Where to buy weed and feed in NZ?

Yates Weed ‘n’ Feed is stocked at major retailers including Mitre 10 and Bunnings, both in-store and online. Independent garden centres also typically carry the Yates range.

What is weed and feed NZ price?

Prices vary by retailer and bottle size. The 4L Hose-On format—covering approximately 260 square metres—typically retails in the NZ$30–40 range, while the 2L version covers 130 square metres at a lower price point.

Is October too late to spray for weeds?

October is not too late—it falls within the ideal Spring application window for most of NZ. The key is waiting until weeds are actively growing and the lawn is showing new growth, not still emerging from winter dormancy.

What actually kills weeds permanently?

No herbicide guarantees permanent weed control—all weeds can reinvade from seeds in the soil or from neighbouring properties. Consistent lawn health, dense grass coverage, and repeat applications at the correct seasonal windows manage weeds long-term rather than eliminating them outright.

Is it too early to put weed and feed on my lawn?

If the lawn is still dormant or soil temperatures are cold, application is premature. The grass should be showing active new growth and weeds should be in early leaf stage—not yet flowering or setting seed—for maximum effectiveness.

What are weed and feed instructions NZ?

Key steps: mow 2–4 days before application; apply in Spring or Autumn; use moderate hose pressure for Hose-On format; allow no rainfall for 24–48 hours after; expect visible results within 2–3 weeks and full weed kill within 4 weeks.

Weed and feed NZ reviews summary?

NZ user forums report generally positive results when weed and feed is applied at the correct timing. Common complaints centre on slow results (users expecting faster action) and occasional scorch when applied in summer heat or over-applied. Some experienced gardeners prefer separate spot-spray herbicides and slow-release fertilisers for more controlled results.

What experts say

“With granular feed you want to spread them in the evening when it’s cool and water the member well.”

— Justin Newcombe, TV Presenter and Landscape Designer, Yates NZ expert demonstration video

“You only need to use this twice a year—in Spring and Autumn—and always avoid hot conditions.”

— Yates NZ Product Demonstration, Yates NZ YouTube Channel

“Slow-release fertilisers perform well in autumn because they supply nutrients in time with the grass.”

— Yates NZ Garden Expert, Yates NZ seasonal calendar for autumn lawn care

The implication for NZ homeowners is that the twice-yearly cycle is non-negotiable for effectiveness, but the product choice between Hose-On and Granular depends entirely on lawn size and proximity to garden beds where overspray could cause damage.

For NZ homeowners, the Weed ‘n’ Feed decision is relatively straightforward: Yates Weed ‘n’ Feed works when applied twice yearly in Spring and Autumn to actively growing lawns. The trade-off is between convenience and precision—weed and feed covers large areas efficiently but the fertiliser component is fast-release, not slow, so pairing it with a quarterly slow-release product or using it only as a Spring treatment is a sensible approach for gardeners who want sustained lawn health rather than a seasonal quick-fix. Buffalo grass owners should look for alternative products, and anyone with garden beds nearby should use the granular format to avoid overspray drift.