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Bonide Captain Jack's Lawnweed Brew Concentrate — iron-based selective herbicide, manufacturer product photograph
Bonide Captain Jack's Lawnweed Brew Concentrate — iron-based selective herbicide

Iron-Based Selective Herbicide

Bonide Captain Jack's Lawnweed Brew Concentrate Review

★★★★☆ 3.5/5

our editor rating how we score

4/5 from 261 shoppers at Amazon — their number, not ours.

$28–$35

Typical price · Roughly 640–1,280 sq ft per 32 oz bottle (6.4 gal of spray at 5–10 gal per 1,000 sq ft)

Affiliate links — see our disclosure. Commissions never influence verdicts.

A genuine spot-treatment tool for people who do not want to broadcast 2,4-D — and the only product here that also handles moss, algae and lichens.

Our Verdict

Legitimate for what it actually is, and widely mis-shopped. FeHEDTA burns down broadleaf weeds and moss fast, works in cool weather down to 50°F, and lets you avoid spraying a synthetic hormone herbicide across a whole lawn. Two things to know before buying. UC IPM records that iron-HEDTA causes burndown and does NOT kill roots, so perennial weeds regrow and the label itself schedules a repeat in 3–4 weeks. And at roughly 640–1,280 sq ft per bottle it costs around five times more per thousand square feet than a granular weed-and-feed — which is fine for spot-treating, and expensive if you were planning to cover a lawn.

✅ Pros

  • Selective — kills broadleaf weeds and moss without killing lawn grass
  • Visible burndown within hours; rainfast in about 3 hours
  • Works in cool weather, down to 50°F, when 2,4-D products are sluggish
  • Also labelled for moss, algae and lichens, which the synthetics are not — except in California, where the label excludes that use
  • No synthetic hormone herbicide, which suits pet and pollinator-conscious lawns

⚠️ Cons

  • Burndown only — UC IPM states iron-HEDTA does not kill roots, so perennial weeds return
  • Label schedules a repeat every 3–4 weeks, maximum 4 applications a year
  • About 5× the cost per 1,000 sq ft of a granular weed-and-feed
  • Not OMRI Listed and UC IPM classifies it as a biopesticide, not organic, despite the natural framing
  • Stains thatch; keep off until dry
  • Do not apply above 85°F, and avoid bentgrass — the label lists no approved grass species, only to test a small area first

Product type

Iron-Based Selective Herbicide

Active ingredient

Iron HEDTA (FeHEDTA) 26.52%

Price range

$28–$35

Coverage

Roughly 640–1,280 sq ft per 32 oz bottle (6.4 gal of spray at 5–10 gal per 1,000 sq ft)

Best for

Spot-treating broadleaf weeds and moss without broadcasting a synthetic herbicide

our editor rating

3.5 out of 5

Where our facts come from

Label read on the registrant's own PDF

EPA Reg. No. 67702-26-4

Read the label yourself →

We read the printed label published by the company that holds the registration. EPA hosts no PDF for this one, so this is the best available text.

What we found when we read it

Label read 2026-08-02 (Bonide's own label PDF; registrant 67702 is W. Neudorff GmbH, Bonide distributes). Iron HEDTA 26.52% confirmed. Every caution in this record checks out: do not apply above 85F, do not apply to bentgrass, rainfast/irrigation interval 3 hours, maximum 4 applications per area per year, may stain thatch, re-seed permitted 1 day after applying. THE FINDING: the moss/algae/lichen use carries an asterisk reading 'Not for use in California'. Our California page recommended this product for moss; corrected 2026-08-02 in both this record and organic-weed-killer-for-lawns.mdx. The label names no approved turf species at all — only the bentgrass exclusion and a test-a-small-area instruction — so grass_types here is our own relevance judgement, not a label claim.

Where this page and the container disagree, the container wins — the label is the legal authority on rates and restrictions. How to read one yourself.

Where This Product Matters

Matched against each state's actual disease, weed and pest pressure.

🌾 Centipede🌾 Bermuda🌾 St. Augustine🌾 Zoysia🌾 Tall Fescue

Application window: April–May and September, and check every label against centipede before it leaves the shelf

DandelionWhite clover
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass

Application window: June through July, inside the same short window everything else happens in. There is no autumn second chance

🌾 Bermuda🌾 Perennial Ryegrass🌾 Zoysia🌾 St. Augustine

Application window: March–May and during monsoon flushes; Celsius-type products handle 100°F+ windows

Henbit
🌾 Bermuda🌾 Zoysia🌾 Tall Fescue🌾 St. Augustine🌾 Centipede

Application window: Bounded by the label's temperature ceiling rather than the calendar — spring treatments finish before the June heat arrives, and nothing selective goes down again until September cools off

Oxalis (creeping woodsorrel)
🌾 Tall Fescue🌾 Bermuda🌾 St. Augustine🌾 Zoysia

Application window: March–May while weeds are young; avoid spraying drought-stressed turf in summer

⚖️ Label exclusion first: the moss, algae and lichen use is marked not for use in California, so here this is a broadleaf spot-treatment only. What still applies is the cool-weather range, which suits a Mediterranean winter weed flush when 2,4-D products work slowly, and it sidesteps the atrazine setbacks near water.

DandelionWhite clover
🌾 Kentucky Bluegrass🌾 Fine Fescue🌾 Perennial Ryegrass

Application window: May–June and September; high-altitude sun makes stressed turf easy to injure, so spot-treat rather than blanket-spray

DandelionWhite cloverBroadleaf plantain
🌾 Kentucky Bluegrass🌾 Tall Fescue🌾 Perennial Ryegrass

Application window: Broadleaf sprays in May–June and again in September, when the weeds are moving sugars to the roots; skip July and August, when a stressed cool-season lawn takes the injury and the weed does not

White cloverGround ivy
🌾 Tall Fescue🌾 Zoysia🌾 Kentucky Bluegrass🌾 Perennial Ryegrass

Application window: April to late May, then September into October. Skip July and August entirely: this is the transition zone, and a stressed tall fescue lawn takes the injury the weed shrugs off

🌾 St. Augustine🌾 Bahiagrass🌾 Zoysia🌾 Bermuda🌾 Centipede

Application window: March–May and October–November; avoid applications above 85°F

🌾 Bermuda🌾 Zoysia🌾 Centipede🌾 St. Augustine🌾 Tall Fescue

Application window: April to early June and September–October; avoid mid-summer sprays on stressed turf

Oxalis
🌾 Bermuda🌾 Zoysia🌾 St. Augustine🌾 Centipede

Application window: Year-round where the turf is actively growing, which is most of the time; the constraint is heat and drought stress on the leeward side rather than a dormant season

DandelionWhite clover
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue

Application window: Late April into June, then September into October; skip the July and early August heat, which is also when UI's own fertilizer schedule goes quiet

Dandelion
🌾 Kentucky Bluegrass🌾 Tall Fescue🌾 Perennial Ryegrass🌾 Fine Fescue🌾 Zoysia

Application window: May–June and September; fall beats creeping charlie best

DandelionGround ivyWhite clover
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Fine Fescue🌾 Zoysia

Application window: October is the most effective month for broadleaf weeds; never apply above 80°F or to drought-stressed turf

DandelionWhite clover
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue🌾 Fine Fescue

Application window: October, and October is most of it — but check the wind and the date against what is happening in the fields, because early-summer growth-regulator drift is a real seasonal risk here and your own spray carries the same way

Henbit and other winter annuals, which own an eastern Kansas lawn in MarchDandelion
🌾 Tall Fescue🌾 Zoysia🌾 Kentucky Bluegrass

Application window: April into May and again in September–October; avoid July and August, when a tall fescue lawn here is already at its limit

HenbitGround ivy
🌾 Kentucky Bluegrass🌾 Zoysia🌾 Bermuda🌾 Fine Fescue

Application window: April–May and September–October; autumn is the knockout window for the wild garlic that defines a Kentucky winter lawn

🌾 St. Augustine🌾 Bermuda🌾 Zoysia

Application window: March–May and October–November; avoid applications above 85°F and never on drought-stressed St. Augustine

DandelionWhite cloverBroadleaf plantainGround ivyMoss — in Maine usually the correct reading of shade, acidity and compaction rather than a weed to spray
🌾 Kentucky Bluegrass🌾 Tall Fescue🌾 Perennial Ryegrass

Application window: June, then a narrow late-August to mid-September window. Maine's usable autumn is the shortest in New England

Ground ivy (creeping charlie)White clover
🌾 Kentucky Bluegrass🌾 Fine Fescue🌾 Zoysia🌾 Bermuda

Application window: April–May and September–October; autumn is the knockout window for the ground ivy and violet the Piedmont is full of

DandelionGround ivyWhite cloverMoss (shade, acidity and compaction together)
🌾 Kentucky Bluegrass🌾 Fine Fescue🌾 Perennial Ryegrass🌾 Tall Fescue

Application window: A narrow autumn is the real window here: late September into October, after the summer heat and before New England's early frost closes the season

DandelionGround ivy (creeping charlie)White clover
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Fine Fescue

Application window: May–June and September; autumn is the stronger window for perennial broadleaf weeds

Dandelion
🌾 Kentucky Bluegrass🌾 Fine Fescue🌾 Perennial Ryegrass

Application window: Late May–June and September; autumn is the stronger window for perennial broadleaf weeds

🌾 Bermuda🌾 Centipede🌾 St. Augustine🌾 Zoysia🌾 Bahiagrass

Application window: April–May and September, avoiding the midsummer heat restrictions on most labels

HenbitDandelionWhite clover
🌾 Zoysia🌾 Kentucky Bluegrass🌾 Bermuda🌾 Fine Fescue

Application window: April–May and September–October; skip summer sprays on drought-stressed fescue

DandelionWhite clover
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue

Application window: June, then late August into September. In a sub-100-day valley there is no third chance

DandelionHenbit and other winter annualsWhite clover
🌾 Kentucky Bluegrass🌾 Tall Fescue🌾 Perennial Ryegrass🌾 Zoysia

Application window: Late spring and again from late August through September, when perennial broadleaf weeds are moving reserves to the root

🌾 Tall Fescue🌾 Bermuda🌾 Kentucky Bluegrass🌾 Perennial Ryegrass

Application window: March–April and October in the south; May and September in the north

DandelionWhite cloverGround ivyBroadleaf plantainMoss — which in New Hampshire is usually the honest verdict on shade, acidity and compaction rather than a weed to kill
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue

Application window: Late May into June, then late August through September. The autumn window closes earlier here than anywhere else in southern New England

DandelionWhite cloverBroadleaf plantainGround ivy
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Fine Fescue

Application window: May and September–October; autumn is the knockout window for perennial broadleaf weeds

🌾 Bermuda🌾 Kentucky Bluegrass🌾 Tall Fescue🌾 Perennial Ryegrass🌾 Zoysia

Application window: Spring and early autumn; in the south skip the June heat entirely, and in the north the usable autumn window closes by early October

DandelionGround ivyWhite clover
🌾 Kentucky Bluegrass🌾 Fine Fescue🌾 Perennial Ryegrass

Application window: May and September–October; autumn is the knockout window for perennial broadleaf weeds

HenbitWhite clover
🌾 Tall Fescue🌾 Bermuda🌾 Zoysia🌾 Centipede🌾 Kentucky Bluegrass

Application window: April–May and September–October; avoid spraying heat-stressed fescue in July–August

DandelionWhite clover
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue

Application window: Early to mid-June, then late August into early September. There is no third opportunity

DandelionGround ivy (creeping charlie)White cloverBroadleaf plantain
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue🌾 Fine Fescue

Application window: May–June and September; fall applications hit dandelion taproots hardest

Henbit
🌾 Bermuda🌾 Zoysia🌾 Tall Fescue🌾 Bahiagrass

Application window: Judged by wind before season: sustained wind is Oklahoma's normal condition, so the usable spray days are calm mornings in April, May and September rather than whole months

Moss (west of the Cascades this is the lawn problem, not a side note)Dandelion
🌾 Perennial Ryegrass🌾 Fine Fescue🌾 Kentucky Bluegrass🌾 Tall Fescue

Application window: March–May and September–October; the long mild shoulder seasons give more usable spray days than most states get

DandelionGround ivyWhite clover
🌾 Kentucky Bluegrass🌾 Tall Fescue🌾 Perennial Ryegrass🌾 Fine Fescue

Application window: May and September — fall is the knockout window for perennial broadleaf weeds

⚖️ Useful in the shoulder seasons here: it stays active down to 50°F, and moss control matters on shaded, acidic northern lawns.

DandelionWhite cloverGround ivyBroadleaf plantain
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue

Application window: Broadleaf work in May–June and again in September; the September pass is the one that holds, because the weed is moving reserves down

🌾 Bermuda🌾 Zoysia🌾 St. Augustine🌾 Tall Fescue

Application window: April–May and September–October, and never above 90°F — centipedegrass is sensitive to 2,4-D both at spring green-up and in summer heat

DandelionWhite clover
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue

Application window: Early to mid-June, then late August into September, which is the pass that actually holds on perennial broadleaf weeds

Henbit
🌾 Tall Fescue🌾 Bermuda🌾 Zoysia🌾 Kentucky Bluegrass

Application window: April–May and September–October; skip sprays on drought-stressed summer fescue

Henbit
🌾 Bermuda🌾 St. Augustine🌾 Zoysia🌾 Tall Fescue

Application window: April–early June and September–October; avoid herbicides above 90°F

Dandelion
🌾 Kentucky Bluegrass🌾 Tall Fescue🌾 Perennial Ryegrass🌾 Fine Fescue

Application window: May and September, avoiding the intense midsummer heat on the label

DandelionWhite cloverGround ivyBroadleaf plantainMoss — usually the correct diagnosis for shade, acidity and compaction rather than a weed with a chemical answer
🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Tall Fescue

Application window: Late May through June, then a short late-August to mid-September window. Vermont's autumn window is the narrowest in New England

DandelionWhite clover
🌾 Tall Fescue🌾 Bermuda🌾 Zoysia🌾 Kentucky Bluegrass🌾 Fine Fescue

Application window: April–May and September–October; skip sprays on heat-stressed fescue in July and August

Moss (the defining western Washington lawn problem)DandelionWhite clover
🌾 Perennial Ryegrass🌾 Fine Fescue🌾 Kentucky Bluegrass

Application window: April–May and September–October; WSU caps applications at 80°F, stricter than the 85–90°F ceilings used elsewhere

White cloverBroadleaf plantain
🌾 Tall Fescue🌾 Kentucky Bluegrass🌾 Perennial Ryegrass🌾 Zoysia

Application window: April into May and again in September–October. Skip July and August: this is transition-zone country and a heat-stressed tall fescue lawn absorbs the injury the weed does not

DandelionWhite cloverBroadleaf plantain
🌾 Kentucky Bluegrass🌾 Fine Fescue🌾 Perennial Ryegrass

Application window: Early to mid-fall is the favourable window for dandelion and other perennial broadleaf weeds

DandelionWhite clover
🌾 Kentucky Bluegrass🌾 Tall Fescue

Application window: June, then late August into September. UW's own framing is useful: a slow-release application covers a 90 to 100 day growing season, which is roughly the entire Wyoming season

Common questions

Common Questions

How much does Bonide Captain Jack's Lawnweed Brew Concentrate cost?

Bonide Captain Jack's Lawnweed Brew Concentrate typically runs $28–$35, covering Roughly 640–1,280 sq ft per 32 oz bottle (6.4 gal of spray at 5–10 gal per 1,000 sq ft).

What does Bonide Captain Jack's Lawnweed Brew Concentrate treat?

Bonide Captain Jack's Lawnweed Brew Concentrate targets Dandelion, White clover, Broadleaf plantain, Henbit, Oxalis (creeping woodsorrel), Ground ivy (creeping charlie), among others.

What is the active ingredient in Bonide Captain Jack's Lawnweed Brew Concentrate?

Iron HEDTA (FeHEDTA) 26.52%, registered under EPA Reg. No. 67702-26-4.

What is the biggest downside of Bonide Captain Jack's Lawnweed Brew Concentrate?

Burndown only — UC IPM states iron-HEDTA does not kill roots, so perennial weeds return

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