Andrew from Indianapolis writes
Kentucky blue grass lawn
Echelon 4SC Herbicide works on both pre and post-emergent weeds controlling crabgrass, sedges, broadleaf weeds, goosegrass, Poa annua and many other weeds. Echelon 4SC labeled for pre-emergent control of poa annua only, not post emergent. According to the product label Poa annua is a winter annual. Applications of Echelon 4SC Herbicide should be made in August or September to established, non overseeded turf before Poa Annua germinates. Consult local Cooperative Extension Service for more specific applications timings for your local area since August and September are approximate timings. Crabgrass control can be attained with by using Echelon 4SC as a pre or post emergent herbicide.
Answer last updated on: 05/22/2014