Vigoro or Scotts Turf Builder Halts Crabgrass Preventer

[stanj]

The label on Scotts Turf Builder Halts Crabgrass Preventer says it last all season long..

How many months is "all season long?

Vigoro has a similar product that states it last 4 months.

I have used Scotts Turf Builder Halts Crabgrass Preventer the last few years, but if Vigoro is the same at $10 less, I may go that way if it last as long and produced the same results.

thanks