When to perform second repot on nursery material?

[MSU JBoots]

Most of my collection is comprised of nursery material. When I repotted them initially I left quite a lot of the original dirt in the center but teased out the roots some and surrounded it by bonsai jack soil. I’m wondering how soon I should repot them again to remove more of the nursery soil? Next spring it will have been 2 years since the original report and for others 1 year. My understanding is it’s not great to have a big rootball different media in the center as it can stay too wet and cause rot or get dry and hypdrophobic in the center. I’m more worried about the rot at this time.

 

[TrevorLarsen]

Depends a lot on which species you have. Deciduous you can after one year, but pines you should wait 3 years.

 

[MSU JBoots]

Depends a lot on which species you have. Deciduous you can after one year, but pines you should wait 3 years.

The only deciduous I have repotted was bare rooted bc I made it a root over rock. However the rest are pines, spruce, and junipers. Thanks for the help.

 

[Scrogdor]

Most of my collection is comprised of nursery material. When I repotted them initially I left quite a lot of the original dirt in the center but teased out the roots some and surrounded it by bonsai jack soil. I’m wondering how soon I should repot them again to remove more of the nursery soil? Next spring it will have been 2 years since the original report and for others 1 year. My understanding is it’s not great to have a big rootball different media in the center as it can stay too wet and cause rot or get dry and hypdrophobic in the center. I’m more worried about the rot at this time.

Usually what I do is get rid of most of the garden soil, and then I'll mix garden soil with something like bonsai jack to replace it. like 50/50 mix. Then next time I repot I'll fully transition to Bonsai soil or a substrate that fits your needs. I personally need a little extra organic substance in my soil because there are periods where I can't water for 2-3 days. But yeah the soil should definitely be uniform throughout, otherwise you get stressed because one part is drying way faster than the other.

 

[bwaynef]

Deciduous I bareroot and repot the first spring its in my care. Conifers, I half bareroot the first spring, then the next spring after the tree has responded strongly, (so, possibly the next spring, possibly 2 years later) I bareroot the other half.

 

[MSU JBoots]

Deciduous I bareroot and repot the first spring its in my care. Conifers, I half bareroot the first spring, then the next spring after the tree has responded strongly, (so, possibly the next spring, possibly 2 years later) I bareroot the other half.

Do you ever do any pruning/styling in between or solely focus on root work for the first few years?

 

[bwaynef]

I work trees in between repots. If the tree is weak I don't, but usually trees will make significant strides after the frst half bareroot procedure.

 

[Shibui]

There are very few species that would have a problem with repotting 2 years in a row. Younger trees are far more resilient than older trees. Many of my smaller shohin sized bonsai have been repotted annually for many years.
I've noticed that repotting does not slow growth. On the contrary, most trees grow faster in the year after repot with the extra space for roots and fresh soil. Even pines grow better after repotting and I regularly do a full repot on young pines.

 

[MSU JBoots]

Thanks @Shibui I always appreciate your input. I will think more about it this winter. I looked back and a couple of my spruce reports I actually removed more soil than I thought. However, my Austrian pine and mugos definitely have a lot of nursery soil left. Perhaps I do another repot next year.

 

[RaginCajun]

Late to this party but, with deciduous trees I cut back hard on the roots, wash out all the dirt and replace with bonsai soil 100%. I haven't had much luck leaving potting soil in.. I water so frequently in my hot, humid climate, the bonsai soil needs watering once or twice a day and any dirt stays saturated which causes problems with roots pretty quick. We will hit 105° but with a very high RH, water evaporates but not as fast as you would think at 105°. Good luck to you!