Liquid Harvest Lazer Blue Concentrated Spray Pattern Indicator, 8 oz Review

Our Verdict

The cheapest thing on this site that improves results across almost every herbicide article we publish, and it contains no pesticide at all. Every spraying failure mode we describe is a coverage failure you cannot see: the missed strip that regrows in three weeks, the double-covered pass that injures turf, the overlap you guessed at on a large area, the drift creeping toward a bed. A pattern indicator makes all of them visible at the moment you can still fix them. It matters most on the jobs where coverage IS the treatment — a contact herbicide on gravel, where NC State notes untouched tissue is untreated tissue; bentazon, which is contact-acting; and waxy upright leaves like wild garlic, where the spray beads and you cannot tell what actually stuck. It also pairs with calibration rather than replacing it: knowing your gallons per acre tells you the rate, and the dye tells you whether that rate landed evenly. Two practical notes. It stains — concrete, clothing, gloves and skin, temporarily — so keep it off hardscape you care about and wear gloves. And it is not a surfactant: it makes spray visible, it does not make it stick, so an adjuvant is still a separate decision.