Up till recently things have been great (2 years) but within the past month I have had three seeds "get the tail" in the paper towel, then when I put in soil....nothing. I used to have 100% success but now am worried that I lost 3 in a month. One may have been my fault- the paper dried out over night. The most recent one has been in soil for 5-6 days with no sprout. How long before I toss it?