ThatÂs a good question Jos14h. You may get several opinions, some conflicting. HereÂs mine. I would put down Milorganite following the package instructions. ItÂs a little more costly than the pure chemical types, but it is a gentle, slow release, organic fertilizer. It will not burn your lawn and you can put it apply it anytime without the need to water it in. You might consider organic lawn maintenance if you want the best performance from your lawn. Soybean meal purchased from a feed supplier is an excellent fertilizer and is cost effective as well. Good luck with your new lawn, and keep it watered this summer.

For now just put down some kind of regular fertilizer. You don't want to use weed killer until after you have mowed 3 or 4 times.

It's getting a bit close to summer for major fertilization, but I would probably still do it since you didn't put anything out at the time of instillation. Since the temps are warm already, I would go with an organic fertilizer or a half strength dose of synthetic. The growth rate will naturally slow down in the heat of summer, so it is a good practice not to over-fertilize at that time.

jos14h, an organic (farmyard) type of material is best because they work best in the summer temperatures and have a low nutrient content. 'Milorganite' is such a product. If later on you need additional 'greening up' you could put down a synthetic like ammonium sulfate. Use a low rate like 1/4 lb. N per thousand sq.ft. which will give color to the grass and give the microbes something to process.