Q. I would like to plant grass from seed in late fall f in downstate New York. When would be the best time to put down grub killer?
White grubs are immature scarab beetles (for example, European chafers, Japanese beetles, and Oriental beetles). Although all grubs cause similar damage, the treatment you choose should correspond to the species. Homeowners can have their grubs dentified at a local Cornell Cooperative Extension (CCE) office. Please call Cornell Cooperative Extension Service Agent Jerry formore help. He's available before 12 noon usually M-F at 914 285-4620.
Many characteristics of a lawn determine how well grass grows. You can, however, help your lawn to compensate for loss of roots by watering it regularly, providing good fertility, and reseeding damaged areas. Seeding is most successful in the fall. However, grubs will eat seed too. Therefore, if grub numbers are high, you can delay seeding until spring or do an additional seeding in thin areas in the spring.
More about lawns: https://ecommons.cornell.edu/bitstream/handle/1813/68/Lawn%20Care%20and%20Water%20Quality%20Alm?sequence=2&isAllowed=y
No Pesticides: https://ecommons.cornell.edu/bitstream/handle/1813/43857/lawn-care-no-pesticides-NYSIPM.pdf?sequence=1&isAllowed=y
Most important...soil testing, and best lawn seed choice https://ecommons.cornell.edu/handle/1813/3650