5 Best Weed Killer For Thistle | Weeds That Keep Coming

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Three active ingredients that gang up on thistle from different angles, making it harder for the weed to survive.

Nufarm Change Up is the most complete thistle-killer here because it packs three active ingredients: MCPA at 51.05%, fluroxypyr at 6.0%, and dicamba at 4.17%. Each attacks a different biological pathway (growth regulator, cell division, and root transport), so the thistle has fewer defenses. It is labeled for over 200 broadleaf weeds and explicitly lists thistles on the label. The 32-ounce bottle treats up to about 1.5 acres at the lower rate of 0.46 ounces per 1,000 square feet. Owners mention excellent results on tough clover, with one saying “the clover was gone in a little over a week.”

The turfgrass tolerance list is broad: it works on everything from Bahiagrass to St. Augustinegrass and creeping bentgrass. One reviewer in Western Kentucky noted that after tackling a yard full of clover, “there was grass and this product didn’t kill it.” The real trade-off is the per-ounce cost — it is the most expensive liquid concentrate here — but you are paying for triple chemistry that single-active formulas like the Fertilome cannot match. Choose this when you have a recurring thistle problem that does not respond to simpler weed killers. pass on it if you are on a tight budget — the Fertilome above will handle most thistle at a lower cost per bottle.

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A full gallon of farm-grade concentrate that keeps thistle out of pastures and lawns at the lowest cost per ounce.

You get 128 fluid ounces (1 full gallon) of 2,4-D Amine at 47.2% active ingredient — nearly the same chemistry used in large-scale agriculture. The maker says you need only a few ounces per gallon of water, so this single bottle makes dozens of tank-fulls. One customer observed it “works great killed weeds within few days. Make sure you follow the instructions and mix it correctly or you will fry your grass.” That is the honest warning: 2,4-D is strong, and over-mixing will burn your lawn. But used at the right rate, it is a cheap, effective solution. At 128 oz, the ALLIGARE holds 4 times the volume of the Nufarm Change Up (32 oz) and the Fertilome (32 oz), making it by far the lowest cost per ounce.

It works on lawns, pastures, and even aquatic sites like drainage ditches and pond edges. The same buyer added “mixes easy with water, and great bottle size.” The main limitation is availability: ALLIGARE has restricted sale in several states — one reviewer in Texas noted they could no longer buy it. Check your local regulations before ordering. Buy this for large properties, pastures, or fence lines where you need gallons of spray. Buy the 32 oz bottles above if you only have a small lawn — they are easier to mix precisely and less risky to over-apply.

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Herbicidal soap that wilts thistle in 20 minutes and is safe enough for your vegetable garden.

Sunday Weed Warrior works differently than the chemical herbicides above. It is an ammoniated soap (herbicidal soap at 22.00% concentration) that dehydrates the weed on contact — it does not translocate like dicamba or 2,4-D. The result is fast: you see wilting in 20 minutes, and one impressed buyer said “after about 4 hours all the weeds are gone.” It is OMRI Listed for organic gardening, so it is safe around raised beds and edible plants. It is also non-staining on concrete and asphalt, making it good for driveway cracks and patios.

The kit comes with two 22-ounce concentrate bottles plus a reusable mix-and-spray pouch and a battery-powered wand sprayer. At 44 total ounces of concentrate, it makes 2 gallons of finished spray — 45% more total liquid volume than a single 32-ounce Fertilome or Nufarm bottle. However, it is non-selective: it will kill any grass it touches. That makes it better for spot-treating thistle in patios, gravel, and flower beds than for spraying across the lawn. One user highlighted “the grass in sidewalk cracks dies quickly. Large clumps along the fence don’t do as well” — meaning big established thistle clumps in soil may need a soaking. Another added “it goes pretty quick … you gotta make sure you put enough on each weed.” This pick is perfect for organic gardeners who need to kill thistle on hard surfaces; look elsewhere if you need to spray a lawn full of thistle, because you will kill the grass too.

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The spread-and-forget granule that covers a massive 15,000 square feet in one bag — no mixing required.

If you hate mixing and spraying, this is your alternative. Jonathan Green Lawn Weed Control is a granular post-emergent broadleaf killer that you spread with a standard lawn spreader, like fertilizer. It controls over 200 broadleaf weeds including thistle, using Trimec as the active ingredient — a proprietary blend of 2,4-D, MCPP, and dicamba. The label says it works on both cool and warm-season grasses and will not burn your lawn. For tough weeds, Jonathan Green recommends a second application 30 days later. One very happy buyer said “in days I saw the weeds starting to turn colors, dry up, become brittle, and die.”

The big advantage is coverage: a single 30 lb bag covers up to 15,000 sq ft, which is about a third of an acre. The Fertilome and Nufarm liquids above cover only a few thousand sq ft per bottle at most. The trade-off is slower results because granules need to be watered in (or applied to a moist lawn) to stick to the weed leaves. One shopper added “did absolutely nothing to reduce dandelions, its been 2 weeks” — though most positive reviews far outnumber that one. Also, you cannot spot-treat one thistle plant; it is a broadcast treatment. Choose this when you have a large lawn (over half an acre) and want to walk once with a spreader. Look at the liquids above if you prefer to spot-spray only the thistle clumps.