Per the package for Zenith Zoysia Grass Seed it should germinate in 2 to 3 weeks. It can take a year or so to get established.
Per the manufacturer the Zenith Zoysia Grass Seed, you cannot seed with this product over an existing lawn. You would need to completely kill the current lawn to have bare ground, till the soil and apply according the complete instructions on the label provided on the bag.
No, aerating will not hurt the Zenith Zoysia grass. The best time to aerate Zoysiagrass is in early summer, when the grass is growing rapidly. On very compacted soils, aerating twice a year would not be out of the question. Apply fertilizer and water after aerating so the turf recovers rapidly.
You can use any Roundup product to kill the Fescue quickly and allow you to reseed with the Zoysia within 1-2 weeks usually at most. Keep in mind that zoysia seed is best put down in the spring as it thrives on warmer weather where as in the fall you normally seed with cool season grasses that thrive in the cooler temps like Fescue and bluegrass.
It is not recommended to just apply Zenith Zoysia Grass Seed over an existing lawn without first killing the grass that is there. Zoysia is too slow growing for the seedlings to compete with existing grass.
It is recommended to apply Zenith Zoysia Grass Seed in the spring.
Zenith Zoysia Grass Seed should not be planted from seed this late in the year, but if it's planted from sod you can. It may have time to root before winter.
As long as the grass has matured, you can mow the lawn.
An unopened bag of Zenith Zoysia Grass Seed should be stored in a cool dry place away from any extreme temperatures and moisture.
Zenith Zoysia Grass Seed only needs to be planted 1/8 to ¼ inch as it requires light to germinate properly.
If you have experience with burning the dormant turf, then it can be very good for a zoysia lawn to be top-burned about every 5 years. This process will release nitrogen and phosphorous nutrients into the soil and create a very green lawn when it grows back. If you are using any pre-emergents, then you would not put down pre-emergent until after this process. However, since burning can be very dangerous, we do not recommend that homeowners attempt this kind of treatment. This would need to be performed by experienced professionals and may not be allowed in all areas.
Zenith Zoysia Grass Seed is Zenith variety simliar to Meyer and is to be used in warm weather zones. The best way to determine if this turf will grow in your area would be to contact either your local Master Gardner or Department of Agriculture to get feedback from what others in your area have had success with in your area. Another option is to contact the manufacturer directly as there would better know what the seed can tolerate. Patten Seed Company can be reached at 800-634-1672.