Doing a germination test is a great idea before planting seeds that you're not sure are still viable (able to grow). That may be the case because the seeds are old, or have been exposed to water, light, heat, insects or other conditions that aren't ideal. Germination tests give you a good idea of how resilient your seeds are, so that you can make a plan for how many of them to plant or whether it is worth planting them at all.