It seems like heterogeneity in soil particle sizes isn't too worrisome, and especially if you consider how every climate's and tree's individual needs will determine the ideal soil components/sizes, I'm not too afraid of that per se. However, my soil components are very different in size (see picture).
Particle sizes ranges from 15mm lava rock to 4mm DE. Any thoughts on how this might impact growth? I've tried crushing the lava rock to get things somewhat more evenly sized, but that yielded a lot of dust.
Would like to hear all your thoughts.
It's so funny you've posted this as I came to this subforum to make a thread on this very topic!!!!
In
@Walter Pall 's legendary water/substrate/feed article ("In Plain English"), same-size aggregate components are advocated. I have found, over the years, that I dislike this....however I should put the big caveat here that, unlike Pall, I'm not growing in lil bonsai containers or even what most of you guys would consider 'grow containers', so maximizing feeders//volume isn't as critical for my trees since they're in the earlier phase of their development therefore some common themes are:
- rapid/forced growth in big containers, with
- relatively frequent 'hard cuts', both to roots&shoots, over the years while creating initial 'skeletons' of the rootplate & the canopy
So, since I make my own mixes (btw Re the scoria-dust you mention--- just use a screen & hose, you should be doing that anyways it's important to rinse otherwise you can sometimes be inadvertently adding a ton of fines to your containers!), this concept of particle-size is something I've pondered a while and have found I actually
prefer irregular/mis-matched particle sizing. I find my grow-boxes better with larger particles, in general, on the bottom (and ridiculous drainage, if it's not a rootmaker type container) so 'skew' it that way (and often use a different mix with some finer stuff as a top-dress) but, throughout "the main rootzone" I like having interspersed chunks of nonporous rock(porous scoria still does this job fine enough though) because, when doing root-prunes, it lets you "get at" the rootplate better and structure/clip/etc to help set it up better, earlier.
I also no longer make any mix w/o including, at least a lil, of the following:
- shredded tan sphagnum, and
- shredded 'mini pine bark nuggets' (this stuff is the myco's favorite, at least around my garden!)
Should note that anything going into a container is
thoroughly screened&rinsed beforehand, the only fines are things like a handful of compost or worm castings as top-dress on some species during their strongest grow-periods but I can't help but assume that such fines are being broken down and used as they settle-through and I don't use much. Have crazy amounts of worms in all containers (well all closed containers, they don't seem to like growbags as much..)