RM43 Mix Calculator: Two Rates, One Big Warning

The two label modes — and why they're dosed differently

Total vegetation control is an area-dosed treatment like a pre-emergent: the imazapyr needs a specific amount of active ingredient per square foot of soil to hold a residual barrier, so the label specifies 7.4 oz per 1,000 sq ft and the water (≈1 gal per 1,000 sq ft) is just the carrier. Spray it like paint — complete, even coverage of the whole surface, not just the weeds. Spot control at 6 oz per gallon works the opposite way: you're treating individual plants by concentration, coverage follows the weeds, and the lighter soil loading is why the label frames it as "control with some regrowth acceptable."

The practical test for which mode you want: should this ground stay bare? Driveways, gravel pads, fence lines, around outbuildings — bare-ground mode. A weedy patch at the edge of usable land — spot mode, or honestly, plain glyphosate if you don't need residual at all.

The imazapyr rules: where RM43 must not go

Imazapyr is what you're paying for and what you have to respect. It's soil-active, root-absorbed, and mobile enough to matter:

• Root zones of keeper trees and shrubs — roots extend well beyond the drip line, and imazapyr taken up by roots can injure a tree months after a tidy-looking fence-line application. Keep a generous buffer.
• Slopes and drainage paths — treated soil that washes downhill carries the residual with it; the dead strip below a sprayed slope is a known RM43 signature.
• Anywhere you'll replant — beds, garden edges, future lawn. Up to a year of control means up to a year of nothing germinating.
• Near water — the label's aquatic restrictions apply; this formulation isn't for ponds, ditches that flow, or shorelines.

None of this is a defect — it's the product working as designed. The label's site list (driveways, fence rows, gravel, around farm buildings) is short on purpose, and the one-year commitment is the deal you're making at checkout.

RM43 vs the alternatives

Against regular glyphosate: RM43 kills the same plants but adds the residual — choose by whether the ground should stay bare. Against Roundup Extended Control (glyphosate + imazapic): same concept, different residual chemistry and pack sizes; RM43's larger jugs typically win on cost per treated square foot for big bare-ground jobs, which is why it owns the farm-store shelf. Against Remedy Ultra: no contest — Remedy is selective (saves grass) and RM43 is scorched earth; pasture brush is Remedy's job. Application gear is the same either way: a backpack sprayer↗ covers bare-ground strips evenly, and a coarse, low-drift setting matters more here than with non-residual products.