I'm in zone 6. We live on 5 acres and have built new and are trying to get a lawn going. The new grass coming in (about 6 weeks old now) is turning yellow except where my dog pees. There it is nice and green. It's like the nutrients have been washed down the hill, as the grass a bout ten feet below still looks OK. It looks like it needs food. Can I still fertilize this time of year? The rest of the grass around the rest of this area is still green. Should I use more starter fertilizer or a winterizer?