If you seeded sometime after early March then inconsistent growth with lots of weeds would be normal. Spring, and late spring, is a poor time to seed grass. KBG may not get really consistent for 3 years. Weeds would be normal because you put seed down at exactly the same time as the summer annual weeds are trying to germinate. When you watered your grass seed that set up perfect conditions for weed seeds. Fall is a much better time to put northern grass seed down.

What is your current watering schedule? How often and for how long do you water?

Thank you for your response. I currently have my lawn being watered at 4:30 am for 15 minutes and 1:30 pm for 15 minutes every day. Some of the zones in the backyard do overlap. The front does not. When the temperature has been warm (above 80) I have added an extra 10 minutes cycle in the front. What do you recommend I do in the fall? Should I be doing anything differently for the rest of the summer? Thanks again!

Just to add... My plan was to spray Tenacity in August to kill the weeds and prevent any zoysia from creeping up and then reseed and fertilize.

Watering for mature lawns: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall.

Having said that, you don't have a mature lawn yet. I would split the watering schedule for an immature lawn. Instead of 1 inch every 2 weeks, I would give it 1/2-inch every week. Next spring go to the regular once a month regimen for lower temps and as the temps warm up, modify the timing appropriately.

8 hours for each zone or 8 hours all together? I will try the cans and see how long it takes for me. Btw- thank you for your help. I was initially told that I just need to keep the lawn moist but not soaked but I guess it makes sense that once the grass begins to come in my watering schedule would need to change.

what kind of soil do you have? have you had a soil test? This isn't your issue but it can better help us understand what you are dealing with