I'm also perennialy short of room to pot up into. I lose more seedlings that way! Also, I usually start in trays of cells or propagation trays, not paper towels. I usdually think of the "paper towel/baggie" method as a way to break dormancy (stratification for difficult, fussy perennial seeds.
My belief is that anything showing any root has started metabolising and cionsuming its seed resources. My opinion is that as soon as possible, the roots want soil and the seed leaves will need light as soon as they appear. Also, a fridge is cold and dark. Most seedlings I know grow better between 55 and 75 or 80, than they do in the dark at 40F (4 C). But I mostly start crops and other annuals,.
On the other hand, I have more experience killing seeds than with getting adult plants established. My failure is usually to leave them in a propagation cell or small pot too long. But I believe that a paper towel and baggie in a fridge is even worse for a seedling than too little root zone in potting soil.
Pot up early and often! (But if anyone else offers advice, they probably have more SUCCESSFUL experience than I do.
I tried to find Dr Deno's advice, but found more details about specific species than general guidance about how soon to move to pots. But he did have a lot to say about keeping pots humid but aerobic by "bagging them in thin Baggies loosely closed. (NOT thick Zip-locs with closed zippers!
Extracts From Deno's "Seed Germination, Theory And Practice"
p.13-14
"high wet strength paper towel ... perforated section of paper towel is torn off and folded in half three times in alternating directions to give a rectangular pad 2.5 x 4.5 inches."
" Fold the Baggie several times so that evaporation of water from the towel is inhibited, yet leaving ample access to air to insure aerobic conditions."
"A special warning is made about certain brands of paper towels that are
advertised for their softness. These become mushy very quickly. It is important to use
high wet strength paper towels, and the plain white type are preferred."
"Also a special warning against Ziploc bags and other polyethylene bags that are of thicker polyethylene film and are constructed to seal tightly. Polyethylene film is permeable to oxygen but not water (even though water is the smaller molecule) so that by using the thinner polyethylene, the permeablility of the film to oxygen helps maintain aerobic conditions."
"The paper towels remain moist for periods of months and only need to be
remoistened at periods of two months or longer. The towels are inspected and the
germinated seeds counted at least once every seven days and as often as each day if
germination is occurring at a rapid rate."
Also see pages 55 and 56.
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Persistent URLs for Dr. Deno's book
"Seed Germination, Theory And Practice"
and supplements:
http://hdl.handle.net/10113/41... (1993)
http://hdl.handle.net/10113/41... (1996)
http://hdl.handle.net/10113/41... (1998)
Those are permanent links to reach specific documents at this website:
http://agspace.nal.usda.gov/
National Agricultural Library (NAL)
NAL Digital Repository
Digital Documents Repository (DDR)
"AgSpace": a centralized location for USDA publications
under:
Other Agricultural Collections
Other Agricultural Research and Information
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Another germination link I like:
http://tomclothier.hort.net/
P.S. When I do germinate seeds on wet paper, I use one layer of thin coffee filter in a glass bowl, and nest several of those together. They nest loosely, so I have to water every few days. But I have to check for roots every day, so no problem.
Why don't I do it Deno's way? I started my way decades ago when I did a little indoor growing, and now I'm set in my ways. Also, I don't have to start 100 samples at the same time, or keep them for months. If a seed is THAT hard to start, I'll grow other things until I'm so jaded and have so much time on my hands that I WANT a challenge.
