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Cold, Moist Stratification

Posted by mayzu 5 (My Page) on
Fri, Feb 19, 10 at 22:46

I have yet another question for you all!

I have several types of seed that need cold, moist stratification (swamp milkweed, common blue violet, joe pye weed, New England aster, prairie coreopsis, etc.).

I've been reading every possible article on the issue and can't figure out what kind of stratification material to use.

Some say to use ONLY peat moss or ONLY vermiculite. I cannot find a store that only sells one or the other; they're usually mixed. At Menard's, there are two different mixes: one by Schultz that contains some amount of Miracle Gro, and another generic type that contains bark.
Neither of them are labeled as being "sterile." Should I assume they are? Does it matter that the peat and vermiculite are mixed? And might the extra materials (Miracle Gro or bark) pose problems?
I will keep shopping if need be.

On top of that, other sources encourage using sand. I cannot find any other type of sand besides regular play sand sold in huge bags. Would this be useful? Or not sterile enough?

My biggest fear is growing MOLD ... MOLD MOLD MOLD!
I will do anything to avoid it!

Does anyone have personal experience with this?

Follow-Up Postings:

RE: Cold, Moist Stratification

You are looking for a material that will retain water, and have air spaces.... so yes peat & vermiculite mixes work well.... the material is not steril so may wish to heat in oven to kill spores..... If mix & seed is in a air tight container & soil was steril there will be a very low case of mold... Yes sand. paper towles etc will also work...

RE: Cold, Moist Stratification

Mold should not be a problem at stratification temperatures. I use for most seed damp paper towels sealed in zip lock bags in the refrigerator. Some seed does better with paper coffee filters as the radicals do not penetrate into the paper as quickly. Al

RE: Cold, Moist Stratification

I usually use chopped LF sphagnum or sand in small tupperware containers for cold moist stratification.

RE: Cold, Moist Stratification


For my cold moist stratified seeds I don't use any different soil than my warm seeds(exm. tomatoes). I use a soilless mix(I like fafards or sungro)...just check at your local greenhouse...I am sure they will sell you what they use if they don't carry some of the name brands. Now, I do usually add chicken grit to my outside treatment containers...making a crumbly mix for good drainage. The chicken grit you can get at a feed store.

And don't worry about the mold...never had a problem with it. And I get my sharp sand at the concrete plant...more coarse with lots of rock sizes in it...many times I use this mixed into the soilless mix as well.


RE: Cold, Moist Stratification

  • Posted by dicot Los Angeles (My Page) on
    Tue, Feb 23, 10 at 17:01

I use 75% vermiculite, 25% coarse, washed sand and I douse the container & mix with 3% hydrogen peroxide. It makes for easy mixing into a seed starting mix for flats or cells.

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