Should I install sod or plant seed? It's a common question with a somewhat complex answer. There are benefits to both options; this information may help you decide.

Sod is usually chosen by homeowners in a new build process as it is often a requirement of the homeowner's association. A clear advantage of sodding over seeding is the immediate aesthetic improvement of the property. In addition, the flexibility of being able to walk on and use the new turf areas within only a few weeks is desirable to most everyone.

Washout can be an issue with a new sod installation on a steep hill, although the sod can be staked to help prevent this. Depending on the quality of the existing soil in your yard, additional topsoil may not be necessary.  It is difficult, however, to keep sod alive in an area that does not get at least four hours of sunlight a day. So, if you want to install sod in a shady area, over-seeding with a shade-tolerant seed may be required to keep the area from thinning. Consistent watering is necessary with new sod. I would not recommend installing sod if you do not have an irrigation system or a lot of daily time to water until it becomes established. For the health of new sod, it will require 4-6 fertilization applications per year.

There are many instances where grass seed is the better option. For extremely large areas or very small areas, seeding works great. Also, there is a large selection of seed to choose from which helps in difficult areas. Seed works much better than sod for shady areas and is a much quicker process that requires less water and does not require an irrigation system. 

There are several things to consider before you install seed; the main one being its germination rate. To obtain a lush lawn, it may take several months and multiple seeding applications. Seed can easily wash away with heavy rains; therefore, it is recommended that an erosion blanket be applied in necessary locations and conditions. For the best results, topsoil should be installed before any seed application. 

In the end, there is not much of a price difference between seed and sod when you factor in the fertilization and topsoil requirements. The choice is up to you and what works best for your situation.