Answer: I would choose one product or the other to use now. Since they are both fertilizers, using both would cause burning problems in your lawn. I'd hold off on the crabgrass preventer. This is best used in the early spring when the temperatures are cool and when the crabgrass is most vulnerable to herbicides. Use the turfbuilder with Plus @ Weed Control now.
Best wishes with your lawn!
Q&A Library Searching Tips