I'm aerating (core aerator) my lawn today and reseeding with Scott's High Density Seeds. Can I mix it with Scott's Weed & Feed with Ant Killer or should I wait to add that to my lawn at a later time?
Sorry about that!!!
1) Generally you don't want to mix two different products in the same spreader unless you know exactly what you are doing. It's difficult to guess the amount put down for each given different particle size and application rate.
2) In all cases I've seen, you can't put down seed and weed killer at the same time. You generally have to wait approximately four weeks after doing one before doing the other. Same goes for pre-emergent with the exception of Starter Ferilizer plus Crabgrass Preventer.
I would recommend applying the seed and Starter Ferilizer plus Crabgrass Preventer now and then a weed and feed product in about 6 weeks. Don't forget to water alot. If you still don't have stable blades of grass after 6 weeks, don't apply the weed killer.