Answer: You have an exciting project ahead of you! First of all, the soil may be good stuff or it may not; unfortunately there is no way to tell by just looking so you need to perform a soil test to find out. Your County Extension office can help you with that and help you interpret the results. The phone number in New York City is: 340-2900.
It is true that sod is expensive compared to starting a lawn from grass seed. Sod can also look better faster, so that may be a factor in your decision. (Your County Extension can also help you determine which type of grass would be best given your soil and other growing conditions.) In either case, your soil will probably need additional organic matter added, as well as possibly other amendments prior to planting. You will use the test results to help figure out what you need to do.
By the same token, most flowers (whether annual or perennial) need a well-prepared bed to give the best results, so be sure to include that in your soil testing and planning.
Late summer and fall are a great time to prepare the soil for planting and early fall is a good planting season, so you are smart to start planning now!
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