mom2goldens said: ...
Rick is talking about pine bark (screened) and large vermiculite. This sounds like a really "chunky" seed starting mix. I like my seed starting mix to be really fine, so those really teeny-tiny seeds don't sink down so far they won't germinate.
...
.
Yes, mine is
very coarse and chunky, by design. That may be why I seldom hear of anyone using screened bark for seeds. The Pro-Mix-like-stuff and the finest bark fibers provide plenty of water retention. The coarse bark "grit" provides the voids which supply channels for air to diffuse through.
(Maybe the Pro-mix-like stuff by itself would have provided enough air. But after I drowned too many trays of seeds using a cheap mix that was almost powdered (brown, cheesy) peat, I went as far as possible in the other direction.
Another reason I add bark to Pro-Mixy stuff is that bark is around 4 to 8 times cheaper.
Al (Tapla) and other reading convinced me that seeds don't need fine, water-retentive mix around them, they just need contact with moisture and plenty of air. Seeds would probably germinate aeroponically if the humidity was 100% and there was an occasional fine mist.
The way I overwater, means that MY SEEDS ALWAYS NEED MORE AIR.
Anyone who HAS mastered watering seeds so they don't drown should take a bow. To me, that's like flying, walking on water and squaring the circle. How do they DO that???
I imagine that they must have a system like the way my father made a martini. Just SHOW the vermouth bottle to the cocktail. Maybe loosen the screw-cap briefly to allow some vermouth vapors out.
I do have to lay down a thin layer of medium vermiculite (I do have a LITTLE) on top so that tiny surface-sown seeds like petunias don't fall down into cracks.
My main controlling factor is that I have never mastered not-over-watering. If I have a fine mix, I drown the seeds. One year I had zero germination in 2-3 trays. Coarse mix assures air, which prevents seed rot and damping off.
