The other day I planted a flat full of seeds. To ID which space has what seed, I used a toothpick and some masking tape and wrote the name of each seed, then inserted the toothpick. Easy plant ID using
materials you already have!
Here is a photo of one of the seed flats with all the ID toothpicks. You can see last year I used this same flat, and used masking tape to ID each row. This year, I planted more varieties of seed, but fewer of
each, so labeling each row wouldn't work. I find that I can almost always solve every problem with things that I already have, rather than going out to buy something.