Q.How Long Before My Seed Potatoes Start To Sprout.
I purchased some seed potatoes from reputable nursery and I have planted them in approx. 4 inches of earth.. I am new to gardening…and did not chit them. I keep checking to see if they have started growing but no growth showing yet. I planted them around 20 days ago.

Certified GKH Gardening Expert
It can take a few weeks for seed potatoes to sprout, but if the ground is too cold, too dry or too wet, there could be a problem. I am also wondering if the soil is well-draining and if, perhaps, they were planted a little too deeply. Here's an article that should help:
https://www.gardeningknowhow.com/edible/vegetables/potato/seed-potatoes.htm