Over seeding is done most commonly spring and fall due to milder temperatures and after leaf clean up, de thatching and after aerating!
Aeration Spring & Fall
Spring and fall aeration is done after spring and fall leaf clean up. It helps to promote more oxygen to the root structure of the grass. This helps the grass to grow easier as well as thrive better in its natural climate!
Spring & Fall Clean up
This is just as important as anything else! It helps to promote a more aesthetically pleasing lawn but also rejuvanates the grass to grow as well as not compete for nutrients among other things!
This is typically done on deciduous trees spring or fall when there dormant. Especially oak trees as this will stress them out when the pruning times are wrong, it can promote oak wilt. Coniferous trees are different there the ones that don't drop there (leafs) typically needles. They don't go dormant so there different! This is why its best left to the experts for all your tree pruning needs!
This is also done pretty much anytime of the year whens its not hot outside. It is however a safe practice like the trees to not trim these hedges but just spring and fall.
Typically done early spring, spring, summer, late summer and fall! This consists of weed and feed, broadleaf killer, pre emergents, grub control and more depending on your individual needs! If applied in high quantities or during high temperatures you can ruin your lawn for years! Best left to the pros who are liscenced!