2 of 2 people found this helpful
You can almost certainly tell if seeds are good by opening one up and looking at its cotyledon. It should be fresh looking; not dry or shriveled.
The easiest way to check is to do the Water Test. Take your seeds and put them into a container of water. Let them sit for 15 minutes. Then if the seeds sink, they viable; if they float, they most likely will not sprout. This method, in my opinion, is a good way to check your seeds. For surer results, try performing a Germination Test.
Germination Test - Take some of your seeds, and place them in a row on a damp to slightly wet paper towel and place them inside of a zip-lock bag. This will keep them moist during this process. Next you'll place them into a warm location and check on them at least once a day to see if they have started germinating and to look at moisture inside bag. If it needs more water, carefully mist the towel to where it is damp, but be careful not to apply too much water. Make sure the location you have chosen is away from exposure to direct sunlight. This can overheat your seeds. In a several days up to a couple of weeks your seeds should have started to germinate, depending on the type of seeds. My "good rule of thumb" is to wait roughly 10 days for any signs of germination. Once time has allotted check and see how many germinated. If more then 5 sprouted, than your seeds still have a lot of vigor left in them! Less then 5 yours chances are slimmer.