>> an 1/8 inch screen for the fines.
Yeah!! That's what I'm talkin' 'bout!
I mainly drowned seeds when I used peaty mixes. I don't think, I ever put much peat-in-a-pot.
I called them "peat powder" mixes back when I bought junk brand name mixes from HD. Then I found pro mixes, and they are much better. But I refuse to make potting mix or even seed-start mix from shredded dollar bills! ("Orchid bark" must have the highest markup of any garden product sold.)
>> I don't use the super fine bark pieces by themselves for the wintersowing, but they're mixed into the medium-bark potting mixes.
I also have to mix and match. I get too much, too fine stuff from most bags called "mulch". I've been working that off by mixing it with somewhat-too-big stuff from bags of small nuggets.
I also had the same experience at good nurseries: nice clean bark mulch, dry, not smelly, and more shreds and chips than powder or nuggets. Good aspect ratio!
My dream COARSE pine chip would be
0.5 to 1 mm thick
1 to 2.5 mm wide
as long as fits in the pot! well, up to 1.5 inchs or 3 cm
My dream medium fiber would be flexible:
0.2 to 0.5 mm thick
.5 to 1 mm wide
1 to 2 cm long (1/2 - 1 inch)
Then, if I was replacing ALL my commercial peat mix with pine fibers and 'fines', whatever size held some water but not a huge amount. (Next time I'll buy my peat mix with mycorrhiza .)
If ALL my bark had to be spherical, I would want coarse grit and BBs -
0.1" - 3/32" - 0.18" ,
2.5 - 5 mm,
then add just a little peat and bark powder, then see how much air was still in the mix.
Maybe coarser. Shape matters!
>> I haven't had much luck with big box store pine mulch, but the local nurseries carry a bark product that works great (after screening, of course).
I had the same experience at HD, but the opposite at Lowes. I bet it varies by region or even by store. Lowes' small bark nuggets were pristine ... but mostly bigger than I want, except for 5 gallon buckets.
>> So far I only have alyssums sprouting.
I discovered what was resistant to clay, slugs, winter wetness and dry summers by tossin g a few "seed mixes" hither and yon when I was a total newbie. Anything that survived by slugs, my climate and my abuse was well suited. Siberian Wallflower (?Bugloss??), Sweet William (
Dianthus barbatus ) and white alyssum were the winners.
White Alyssum come back profusely for me most years, and if not, I have enough seed collected that I can throw some on the sidewalk and it will establish itself in the CRACKS. Nice, like snowdrifts in the summer!
Just recently, I saw that some were germinating in the thin layer of mud and dust ON the concrete sidewalk. The film of brown had turned to a film of green! So I scraped them over onto the bare clay and weeds of my beloved next door neighbor,
, who made me remove a narrow raised bed I had put there for the prior tenant. Then she killed almost everything else living on her property.
I forget what the pink flower is: feral Lavatera?
It doesn't feel like this winter will ever end.
