[Greatgardens]

Usually, the coating on seeds (not "pelleted" coatings) is some form of fungicide. It can help germination under poor "soil" conditions. For some direct-planted crops like peas or super-sweet corn, it works great, especially in colder soil; for tomatoes, probably doesn't do much one way or the other.

In my own experience, I believe that my seeds now last longer, because I have stored seeds in little plastic bags and keep all the packets in a zip-lock bag with a silica gel packet inside. It is pretty easy to still get 50-60% germination off tomato seeds that are 10 or 11 years old. But it does take extra time -- usually two weeks. I had this experience with "Vilma" this past January with two batches of seeds -- 9 and 10 years old. Also, older seeds in unopened Park's "Paks-O-Gold" that the former owners used always seemed to provide better than expected germination.

Once, when talking to Tomato Growers Supply, they explained that some (new-old stock) Burpee Orange Pixie hybrid seeds that I wanted were going to be taken out of an unopened can, and ultimately, they germinated great for me. Now admittedly, for most of us, that is totally unnecessary, especially if growing OP varieties. For hybrids, it might be more useful, if you get one that you really like. You never know when it may no longer be available.