Many perennial seeds, shrubs and trees need a long period of moist cold before they will germinate. In fact, I wrote about the subject fairly recently, including a list of seeds that need a cold treatment. See Time to Give Hardy Seeds Their Cold Treatment. But the technique explained how to sow seeds in small pots that are then stored in the refrigerator for up to 3 months… and not everyone has enough space in the family fridge for pots of seedlings. Fortunately, there is a space-saving solution.
Before I explain that, however, it is important to understand simply putting the seed pack as is in the refrigerator will have no effect. To stimulate germination, these seeds need to be exposed to both cold and moisture. However, you can easily give the seeds a cold treatment without either pots or soil and thus save space.
Just moisten a paper towel and wring it out (you want it to be slightly moist, not soggy). Place the seeds you want to germinate on the paper towel, then fold it in half, pressing the top half down on the seeds to ensure a good contact. Slip the paper towel into a plastic sandwich bag and place the bag in the refrigerator, flat or even upright. It will take much less space than a pot of soil. You can even stack multiple bags on top of each other or place a carton of milk or other objects on top of the bag or bags, so essentially they take up no space in the refrigerator.
Don’t forget to insert a label with the plant’s name and the date you sowed them inside the bag or to write that information on the outside of the bag.
Most seeds will need 2 or 3 months of cold. When this period is over, take them out of their bag and simply sow them in pots of moist soil, reusing their plastic bag as mini-greenhouse until they germinate. Next expose the pot to warm temperatures in a well-lit spot and when the seedlings emerge, remove the plastic bag and grow them on as you would with any other seedling.
There you go! There are more steps involved, but at least you’ll have room for something besides pots of seeds in your refrigerator over the coming months!
Do you foresee any problem that could crop up with my following idea I’ve been thinking of doing? The idea is, after my tiny perennial seeds are done cold-moist stratified, could I just unfold the paper towel with all those little seeds already evenly spaced on it and put the whole thing upright on a tray of moist seed starter mix? I would sprinkle a thin layer on top of the seeds and grow them on. Would they be more likely to mold or also would the roots have difficulty growing down through the paper towel into the seed starter mix? Thank you for taking my question.
I see no problem with your idea whatsoever. It would look much the same as making homemade seed tape: https://laidbackgardener.wordpress.com/2016/05/14/make-your-own-seed-tape/