Seed Germination in a Plastic Bag

While I would not recommend this method for small seeds (they should be put directly in the grow medium) a cheap and easy way to germinate seeds is with a plastic sandwhich bag and a paper towel. This allows the grower to see which seeds germinate and then put a germinated seed in a pot. This is a good way to conserve space if growing in a small space.  If you can only have a specific number of pots you can start a few more seeds than the number of pots you havea in a bag and put the first seeds to germinate in the pots.  I used to keep track of the percentage of seeds that germinated when I had a lot of seeds and stored them (Seed Storage LINK) for long periods of time. After seeds are stored for more than a year less and less will germinate.  After 5 years I have very few seeds germinate.

Click here to read a post describing how to use this technique to estimate the percentage of viable seeds you have.

If you are going to use this method, you want to make sure NOT to over water the paper towel. If you can ring water out of it, it is too wet. You can always add a few drops in a day or two if it gets too dry. Do not let the paper towel become total dry either.  You should open up bag at least every day to check moisture and to look for seeds that have germinated, (Do you see the germinated seed in the bag below?) I used to use a small object to keep the bag open so the top of the bag did not actually touch the seeds.

Another potential problem is that the roots may grow into the paper towel. If this happens do NOT pull the seed out. The most important part of roots are small little projections called root hairs. These hairs are where water and nutrients are taken in. If you pull the plant out of the towel you could damage the fragile root haris and at such a young age this could kill the plant. The pape towel is what should be torn and then just plant it right along with the plant. It will break down and obviously plant roots can grow right through it.

Good Growing,
Dr. E.R. Myers