My professional opinion on the use of sod is that I will recommend it only when absolutely necessary.
The reason we like growing a lawn from seed over sod is that we can choose the best blend of turf grass seed for the specific site/conditions at hand. Please keep in mind that most commercially grown Kentucky Bluegrass blend sod is meant to be installed in areas that have 70% + sun exposure throughout a given day. One important factor rarely exposed by most sod resellers. When the choice is made to grow a new lawn by seed you will need to intentionally “over prepare” the soil and nurture the seed for optimum germination and deep root establishment to ensure great long term results. Sod on the other hand can be simply laid on a “sub-par” soil surface and kept alive as long as there is adequate and routine irrigation available. Other factors that can easily stress poorly rooted sod are everyday foot traffic, pet waste, intense heat, insect activity, minimal watering, excessive watering, fungus, sub-par mechanical maintenance, etc. Even though seed will take a growing season or two to fully establish and reach the density levels you are looking for, you will have great long term results with lower maintenance costs thereafter. Sod on the other hand will look great instantly and usually require a greater initial financial investment, but will also continue to cost more over time to maintain (rebuild fading sod density due to limited initial grass variety selection, avoiding constant fungal related threats, continual need to break through dense thatch layer, etc.). The average sodded lawn retains a non-native soil layer that routinely causes poor air/water/nutrient flow to the lawn’s root zone below. In many cases we are forced to break down this “soil barrier” by performing multiple core aerations, mechanical slit-seeding, power raking/dethatching, etc. each and every growing season to maintain acceptable turf density.
