Need Shimpaku advice for spring

[GailC]

I bought a couple shimpaku two years ago and they have just been sitting in nursery pots ever since.
I simply don't know how to deal with them, especially repotting. They absolutely need to be repotted as soon as possible this spring.
Can I do this once the weather warms and can I do a total dirt removal?
They aren't the healthiest due to being so root bound, I feel like its a do or die situation.

These are my last two trees, everything else has died due to neglect during a heat wave. Would like to at least give these a chance to live.

 

[nutshell]

If they're really weak, only take enough roots off for the soil to drain. Just the matted circling roots against the outside/bottom of the pot. If they're not matted you may only need to loosen them and trim the long ones. Then give them a slightly bigger pot to regain strength and veg out next season. I haven't grown shimpaku before and don't know your zone but maybe someone else can help you with the timing?

 

[GailC]

Thanks. I'm hoping the roots aren't circled yet and are just tight.
I'm really wanting to get them in large grow out flats, just not sure how much work they can take.

I'm used to maples and was far from gentle with those.
Zone map has me in 6 but I would say it more like 4, we usually get well below zero at least for awhile.

 

[nutshell]

If the roots aren't circling but the tree is declining in health repotting could weaken the tree more. A pic would help, but you can just pop it out of the nursery pot gently to look, no biggie.

 

[Brian Van Fleet]

You can bare-root them if necessary. If you’re trying to grow them out, only remove dead roots. Comb everything out and repot into larger containers. Wait until tips turn shiny bright green in the spring, then you know it’s the right time to repot.

 

[Shibui]

I also repot shimpaku in spring - anytime from early spring through to late spring seems to be OK here, even if they have started growing well so no need to worry about 'just as buds start to move' IMHO.
I also agree that they can be bare rooted if necessary. Mine seem to tolerate substantial root removal so if root pruning is needed to make the change I'd do that but growth will certainly be better with less roots removed. The catch is that at some stage those roots will need to be reduced to get the tree into a bonsai pot. My experience is that early root reduction is far better and safer than the same reduction when the tree is larger and older.

 

[leatherback]

They aren't the healthiest due to being so root bound

I'm hoping the roots aren't circled yet and are just tight.

I have the feeling you might be mis-judging the situation. IF the roots are not circling, it for sure is not rootbound. And even IF the roots are circling: Junipers love small opts over big pots. It is not uncommon for junipers to stay in the sam pot long enough for the substrate to be pushed over the lip of the pot, but an accumulating mat of roots.

Make sure you know why it is declining in health and teckle that, rather than assuming it is root-bound.

 

[GailC]

I have the feeling you might be mis-judging the situation. IF the roots are not circling, it for sure is not rootbound. And even IF the roots are circling: Junipers love small opts over big pots. It is not uncommon for junipers to stay in the sam pot long enough for the substrate to be pushed over the lip of the pot, but an accumulating mat of roots.

Make sure you know why it is declining in health and teckle that, rather than assuming it is root-bound.

I was assuming its root bound due to the fact that water has a very hard time penetrating the soil.
The decline in health is due to dehydration. Unless its raining for days at a time or I soak the pots, it just doesn't seem like they get enough water.
That why I feel I need to get them repotted asap next spring. Regardless of what the roots are doing, the soil mass is a mess.

 

[GailC]

I also repot shimpaku in spring - anytime from early spring through to late spring seems to be OK here, even if they have started growing well so no need to worry about 'just as buds start to move' IMHO.
I also agree that they can be bare rooted if necessary. Mine seem to tolerate substantial root removal so if root pruning is needed to make the change I'd do that but growth will certainly be better with less roots removed. The catch is that at some stage those roots will need to be reduced to get the tree into a bonsai pot. My experience is that early root reduction is far better and safer than the same reduction when the tree is larger and older.

Thank you, thats the info I needed. I'll only remove roots that absolutely need to be

 

[discusmike]

What type of soil are they in now?? I always spray mine with lime sulphur when dormant , I agree with other post that it is not declining due to being root bound, I’ve always reported after they start growing n pushing growth which is May in my area, lime sulphur will help with fungal issues and pest

 

[Japonicus]

They aren't the healthiest due to being so root bound, I feel like its a do or die situation.

IN the meantime, you can (probably should) work a nail spike like a tent stake, shaped like a nail,
through the root ball in several locations about the pot all the way down where possible.
When the root ball is not saturated, nor rather dried out, but almost time to water.
You'll be surprised at the difference some good O2, deep watering and nutrients will make.

Sorry to hear everything else has died. That being the case, often, juniper may be past the point of return
but not necessarily.

 

[GailC]

What type of soil are they in now?? I always spray mine with lime sulphur when dormant , I agree with other post that it is not declining due to being root bound, I’ve always reported after they start growing n pushing growth which is May in my area, lime sulphur will help with fungal issues and pest

Just potting soil in nursery pots. They are buried under a couple feet of snow right now

 

[discusmike]

It’s a very good chance the soil is your problem

 

[nutshell]

Peat based? Maybe just hydrophobic after missing a water. If the roots aren't circling/blocking drainage, that would be my guess. How has the foliage declined?

 

[GailC]

Peat based? Maybe just hydrophobic after missing a water. If the roots aren't circling/blocking drainage, that would be my guess. How has the foliage declined?

Miracle grow potting soil. Some of the foliage has died and turned brown, some tips, some on the interior.
The green that remain looks a little washed out. Its buried under 2 feet of snow so I'm going off memory.

 

[girv]

Like others mentioned pictures would be really helpful when you can, and as a more immediate option, maybe water the trees by submerging them for a few minutes to better penetrate the soil if you feel water is not absorbing with normal watering, along with other suggestions made here.