According to my calculations, you are short about 2 lb/k of P2O5 (phosphorus) and 4 lb/k of K2O (potassium). Probably the easiest way to get that 4 lb/k of potassium is to use a balanced NPK fertilizer, like 10-10-10 or 20-20-20. It would also give you 4 lb/k of nitrogen and 4 lb/k of phosphorus. You don't need that much phosphorus but it won't harm anything (except possibly the mycorrhizae). You want to avoid nitrogen in the summer. So if you went with the balanced fertilizer, you would be applying probably 3 applications, one a month for mid August, September, October. The 4th could be next year. Divide the NPK number into 100 to get the application rate (example, for 10-10-10, divide 10 into 100 to get 10 lb/k rate).

An alternative is to find SOP, potassium sulfate, 0-0-50. You could apply that once a month, even in the summer, at 2 lb/k for four months. That would take care of the potassium. Two applications of starter fertilizer in the fall would take care of the phosphorus. Since you're planning to overseed, it would make sense to use this plan, as you could do an application of starter fertilizer at seeding and another a month later. Milorganite could substitute for the second application of starter in the fall. Use bag rate for starter or 25 lb/k of Milorganite at 5-4-0 to get 1 lb/k of phosphorus.

As for nitrogen, the balanced fertilizer plan would give you 4 lb/k, which is more than you need for the year considering that you have already applied nitrogen this spring. If you use the alternative plan (which I think is better), you would get almost a lb/k with each application of starter fertilizer (1.25 with Milorganite at 25 lb/k) and then you could do a winterizer application of a quick release nitrogen in late fall after the grass has stopped growing but before the ground freezes. That would get you off to a good start next spring, when you could hold off on fertilizer until around Memorial Day.

Your organic matter is low. It's good to leave clippings on the lawn when you mow. This fall mulch mow any leaves in your neighborhood that you can gather. If this is new construction, there may not be many trees but do what you can. The compost you're planning will help. Mulch mowing leaves is like making your own compost for the lawn --and you don't have to spread it!

Water in your applications. Milorganite does not need to be watered in. Phosphorus tends to get tied with quickly with calcium in alkaline soil. It's there, just not available to the grass. Using organic forms of phosphorus, like Milorganite, enables a slow release of phosphorus. If you test next year and phosphorus is low, it's probably because of the alkaline soil. It's still there, just unavailable. Such is life for alkaline soil.

I hope the pre-emergent you used is short-lived if you want to seed this fall. Normally, pre-emergent is used earlier in the spring, like when the forsythia bloom. Before seeding, you might do some test seeding in a small area to see if it will come up. Or maybe June 1 is a typo?

Thanks for the great response becky. I'll start trying to find SOP and go with the alternative plan you recommended. Yes I used the pre emergent much earlier. Though I still have a bit of crabgrass between street and sidewalk but that must be due to the concrete temps making that soil warm up quicker than the rest. I'll have to monitor more closely next spring.

You're absolutely correct about there being no trees to mulch leaves with. Maybe I can talk with the city about the leaf collection program in the fall and take a few bags off their hands.

Take lots of bags. I use my leaves and then get the Ieaves neighbors have put out on the street. I scatter them around and mow them in. After a week, I do some more.