Mainly I'm asking if anyone knows a reason why finely shredded pine bark should NOT be used for starting seeds, or winter sowing. I made up 30 pots of WS seeds, THEN someone told me that they never used pine bark with seeds ... but for no stated reason.
I was trying to increase air and drainage by adding fine bark chunks (like 1/16" - 1/8", anyway under 1/4".
I could have used less bark if it had been chipped or chunked instead of shredded, but the stuff on display didn't match the contents of the (opaque) bag. It was fibrous instead of chunky or chips. So I used a higher percentage of the fibrous "fine pine mulch" than I had planned.
I started with a conventional seed starting mix from 'what I had on hand' or bought.
- 4 Qts of Jiffy-Mix plus
- 8 Qts of "Orchid Mix, screened to 1/4".
Both of those were very fine, nearly powder.
- 4 Qts coarse perlite and
- 4 Qts coarse vermiculite.
(The last two volumes are very approximate.)
Because I wanted it to drain faster, stay less soggy, and hold some air (and I "just don't like" Perlite), I kept adding screened, shredded pine bark until it seemed "light" enough. The pine bark is now more than half of the mix.
All by itself, it was almost the right consistency. If I had had an 1/8th inch screen, i would have tried to exclude as much "fine bark fiber" as I could.
If I had had time to drive around looking for chick grit, I would have used that - maybe medium grit. Naybe next year I'll use more pelite, but for some reason I just don't like it.
But I was pretty happy with the result as it seemed airy. Any idea whether bark will kill my seeds for me?