Question
A friend just asked me to apply Turf builder Winterguardw/plus 20 weed control to an approx 3 acre lawn/grass/weed area just don't know the amount of fertilizer required . Can you give me an approx amount of material required. Thanks Todd

Answer
Apply turfbuilder plus2 (weed control) to a WET lawn and let the granules stay on the grass for 24-48 hours. E.g. apply early morning when lawn is wet from dew, and then let the product stay for 24-48 hours (if rain is forecasted in 3-4 days then it is the right time to apply, but do not apply day before rain is forecasted).

Use about 3 lbs of product per 1000 sq feet of this particular fertilizer. Since there is 43560 sq feet in an acre - and based on your information of 3 acres - you need:

43,560 x 3 acres = 130,680 sq feet
3 lbs per 1000 sq feet = 3 x 130.68 = 392.04 lbs.
If they come in 40 lbs bags, you need 9-10 bags to cover your lawn (check the bag size availability locally).

Fall is a good time to fertilize most lawns in the northern half of USA.