How soon after seeding a new lawn do you follow-up with another fertilizer application or do you? When I planted, I followed the recommendations of a soil analysis, tilling lime and superphosphate into soil and a 20-8-8 slow release on top with seed, all at the recommended rates. The grass is filling in and looks good so do I need a follow-up? I am coming up on 28 days since planting and 14 days since germination started. What do you use as a follow-up if anything at all?