Trees in pumice roots

[maroun.c]

Hello,
As I prepare for spring repot and will be mostly using pumice and some argil balls, for soil I'm wondering if the roots will attach to the rather light soil to make a root all that holds the soil at time of next repot. My main concern is about some conifers (pine, juniper and podocarpus) which I'll half bare root this year and next year, where I fear the half bar root part will come.lose of the soil next year when I take it out for the second half. My other thought is that this would be good as itll.allow for an soil change without too much roots.manipulation..appreciate pics of trees in similar soil when you take them out for repot or ur thoughts about this.
Thanks

 

[RKatzin]

I have most of my trees in pumice or pumice mix. Most are at least 2-3yrs since last repot, some are 6-7yrs. Those are mostly pumice/turface mix and a couple still in pure turface.
I'm still getting frost and freezing temperatures so I'm holding off still, but will be starting soon with the repotting and collecting and I'll get some root mass pics.
The trees are healthy and showing consecutive years of good growth so I'm assuming there's good root mass in there.

 

[maroun.c]

Great to hear pumice lasting that long for u. Looking forward.tonsee the pictures.

 

[RKatzin]

I've never know pumice to show any signs of breaking down. It cleans up good and much is on its second or third reuse. Spread it to dry and sift and right back in a pot. Oh, I've even been known the repot right back into the same pumice. But don't tell anybody, I don't want it getting around. Lol

 

[Wires_Guy_wires]

Yes, inorganic soils can fall out when you repot.
It happens. That's why it's sometimes better to wait another year with doing the other half. You want the roots to hold most of the soil in place while you work on the old soil on the opposite part.
That can take two years, sometimes four years to happen.

Maroun, I like your enthusiasm. But the trees I've seen from Lebanon, the ones you show, are not in very terrible soils. Yes, the soil is terrible for bonsai, but its good for keeping a tree in a larger pot. If it was such a terrible soil for your climate, the tree wouldn't be healthy. And if a tree isn't healthy, you should not do a repot.

 

[maroun.c]

Yes, inorganic soils can fall out when you repot.
It happens. That's why it's sometimes better to wait another year with doing the other half. You want the roots to hold most of the soil in place while you work on the old soil on the opposite part.
That can take two years, sometimes four years to happen.

Maroun, I like your enthusiasm. But the trees I've seen from Lebanon, the ones you show, are not in very terrible soils. Yes, the soil is terrible for bonsai, but its good for keeping a tree in a larger pot. If it was such a terrible soil for your climate, the tree wouldn't be healthy. And if a tree isn't healthy, you should not do a repot.

Thanks for the tip, I'm actually starting to think there was something wrong in my gardens (one has less sun and wind exposure) and maybe a bit if overwatering from me that caused all the root rot I had with previous trees. Might just take it slower with the repots of trees that are doing good.
For conifers do u do any branch work before tree is completely in bonsai soil and pot ? I still fear the bare rooting can kill some branches and hence believe its safer to leave as many branches to use after the repot.

 

[Wires_Guy_wires]

I do most of the branch work before repotting on my conifers. If I do it after repotting, the tree moves too much in the fresh soil, and that damages the roots again.
The only conifers that tend to drop branches after a bad repot are larches and spruce/picea. I don't think those grow well in your area, so I wouldn't think about it too much.

 

[Potawatomi13]

Yes to pumice falling off roots at repot.