JBP - Shimpaku repotting question

[Rare plant Pat]

Hi everyone,

I have two larger conifers - the JBP and Shimpaku that are below. They are in cut down nursery pots with strong roots and good free draining mix and have had their first styling.

The containers are 40cm across and 20cm to mix level.

My question is about timing of repotting. Is it too late to repot either of these? The black pine is chock full of male flowers, but these haven't extended yet, but the leaf buds are still tiny and covered with their brown scales.

I'm in Melbourne. If it is the time, how much root can I take off? How about 50%? I am thinking of transitioning them into cut down styrofoam broccoli boxes for this year before putting them into their first bonsai pot next season.

[one_bonsai]

I don't do pines, so can't help you there but now is repotting season. If the buds on the Shimpaku are swelling, then it can be repotted now.

Removing 50% of the roots should be fine. I usually remove at least 50% of the roots on all Junipers when transferring them from a nursery pot to a bonsai pot.

It doesn't really look styled. Looks like you've wired and arranged the primary branches. If it were mine, I'd transfer it to a bonsai pot and not touch the foliage. Once I'm sure it's survived and growing strongly, I'd style it more, probably some time in summer.

[Grant Bowie]

Good advice re the shimpaku; repot but leave all foliage on to deal with later. I did one about 3 weeks ago(early) and its looking fine.’ strength is in the foliage for Junipers.

the pine should be Ok to repot as well. Strength is in the roots For pines (except Radiata) so don’t slaughter it.

[Rare plant Pat]

It doesn't really look styled. Looks like you've wired and arranged the primary branches.

Thanks for the feedback. Do you mean that I should wait until the buds are swelling. They haven't started to move yet.

I didn't really mean I had styled it when I said it had received it's 'initial styling'. Next time I see Kunio Kobiashi I'll let him know as it was him who did the first styling. I'll try and find the before photos.

[Rare plant Pat]

Good advice re the shimpaku; repot but leave all foliage on to deal with later. I did one about 3 weeks ago(early) and its looking fine.’ strength is in the foliage for Junipers.

the pine should be Ok to repot as well. Strength is in the roots For pines (except Radiata) so don’t slaughter it.

Thanks Grant. So you think that 50% reduction will be fine?

[shibui]

I've also been repotting pines and junipers for the past 3 or 4 weeks but would normally do them even later than this. I often repot these later when the buds are extending and have not had adverse reaction so I am confident the root pruning window is quite a bit wider than some experts would have us believe.
Removing 50% of roots is normally OK with both species. I do often take some foliage off as well, especially if they are very top heavy, but yours don't look like they have excessive foliage so should be OK with just the root prune.

[Rare plant Pat]

Thanks Shibui,

I reduced the needles on the pine to distribute the growth - the top was quite thick as you would expect, so that sounds like it will balance out any root loss this season.

[Grant Bowie]

Yes 50% or more is fine on Junipers. i have had a couple of experiences where 90% of roots were removed by curl grub,I then trimmed the overlong roots left off and potted up; no problems.

make sure its stable, I always wire in the tree on the first repotting to make sure its safe from wind and accidents.

grant

[longd_au]

Good advice re the shimpaku; repot but leave all foliage on to deal with later. I did one about 3 weeks ago(early) and its looking fine.’ strength is in the foliage for Junipers.

the pine should be Ok to repot as well. Strength is in the roots For pines (except Radiata) so don’t slaughter it.

Hi Grant, I am curious why you said strength is in the roots for pines except Radiata? Are you able to elaborate?

[TajikBen]

I had the same question on the radiata comment ... (though I realise it is not the main topic of this thread).

[Rare plant Pat]

By all means take it off topic - I was curious too