I am very impressed with your set up. I think I need some lessons in propagation lol.
It definitely looks like your media of perlite and vermiculite is doing great and as for those deep prop pots. Not a problem as these babies got a few years to develop roots.
How much open ground have you got? Seems like you might need a few acres.
One question- I see you are using semi hardwood cuttings? Is that the best timing for good rooting percentages?
I have done a whole load of hardwood cuttings lately as I was too keen to get my season started.
I have under 2acres. The question is how much of that is available to me that the wife allows, LOL
As far as cuttings, yes my best luck has been with semi-hardwood taken a month or two after leaf out.
I have done limited hardwood cuttings and plan on diving deeper next winter.
I am now pruning a lot of maples hard before leaf out to induce new strong juvenile growth for the cuttings. So the pruning clippings I have tried to root. I get them leafing out, but since it can turn back cold and I am afraid to set up my mist system for fear of freezing, they tend to wilt away. This year I am planning on following the same timing but once they start leafing find away to get under mist and also provide some bottom heat. I think the hardwoods will do much better with some bottom heat. I took what had leafed out of the hardwoods but not wilted when I set up my mist tent and placed them in there. 10-20 of them are still going 6 months later. Actually I put them in for a 6 weeks or so then moved to an irrigation area. So they have been out of mist for a few months.
Yes the mix seems to be working good. Although after repotting about 25 of them last week, I think they might be a little wet. So might lower the amount of vermiculite. Maybe 25 Verm and 75 Perl
As far as rooting percentages, especially for spring/summer cuttings, the key to me is regular misting. Mist tents, hand misting can work but regular 10sec every 10-30 min of mist will keep them from wilting allowing the time for them to root.
I found some pretty simple Timer/SolValve all in one that work off battery so I didn't require any electrical work. And then I found some simple misters that can be set up using basic PVC. If you ever think about setting up a tent let me know and ill send you the links of what I tried.
Really liked the pots. Easy to see if rooting out the bottom. Don't care how long they get in the vertical direction, because when I repot them I then trim back and pace the roots in a radial pattern. Since they are so young they haven't hardened into something that is hard to fix.