Stratification of Seeds
Malcolm Harrison
Posts: 36
in Talkback
I am interested to know if anybody has tried the technique of stratification (cold chilling of seeds in a fridge at 2 - 5 deg C) before sowing them in Spring in order to break their dormancy and get better more even germination. I am trying this with my Dahlia seeds I collected last Oct/Nov to see if it improves Germination rates.
If you have had good or bad results please let me know. Thank you.
MH
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Posts
Dahlias come from mexico and other south american countries. they don't need stratification. They need heat. Once they are up, any frost will kill them.
My dahlia seeds that I sowed two weeks ago in a cool greenhouse have germinated and I pricked them out today.
Some plants need stratification, usually those that come from cold countries, like alpines.
I always do this with my Hemerocallis seeds, I soak them in a solution of Hydrogen Peroxide for 24hrs then put them into small ziplock bags with some damp Vermiculite & place in the fridge for 4 weeks
The usual method of stratification is to sow in Autumn, and place outside or in a cold frame for the winter. They then germinate in Spring. I find tender subjects need heat to germinate and not prolonged chilling.
Mark, what is the purpose of the hydrogen peroxide.? I have never heard of this method.
Stratification is good for a lot of hardy trees and shrubs, plants of the ranunculaceae and apiaceae families and paeonies
I leave mine outside or in a cold GH. This has worked for years but has let me down this year due to no cold period
In the sticks near Peterborough
It 's the first year I have tried Hydrogen Peroxide, it kills any mould spores on the seed & is supposed to aid germination.
Like nut, I use this method for certain seeds, particularly trees and shrubs. I'm also having to resort to the fridge this year due to lack of long enough cold spells. Acers in there at the moment.
I'm fortunate in having a fridge extension in the shed. It's full and there's still some left to go in later. If I'd known we weren't having winter this year I would have put them into narrower pots so I could get them all in
In the sticks near Peterborough
I've also got some nematodes in there but I bit my tongue when she asked what they were and said "specials" as I don't think "microscopic worms" would have gone down too well!
It's probably a lot cheaper to run a fridge in an unheated shed, nut.
Much cheaper except when the sun shines in through the window Bob.
I haven't tried any nematodes yet. I tend to live with my pests. Something will eat most things
In the sticks near Peterborough