Oak repotting question for coastal California Bnuts

[BrianBay9]

Question for all you Bnuts in coastal California. I recently bought a Q agrifolia (Coast Live Oak) that is seriously root bound. What is the earliest that you think I can get away with repotting to try to help this situation? Is Nov/Dec too early?

Thanks
Brian

 

[hemmy]

I'll defer to the experts who live in your area that will reply. But where I'm at in Coastal SoCal, we have another month before avg nighttime lows get below 50F. Is that the same for you?
I slip pot year round, but that doesn't help your inner bound rootmass. Another consideration is winter rain and making sure things don't stay overwatered, especially with poorly draining soil.

If it was mine and a specimen, I would chopstick some holes and repot in Jan. But if it's pre-bonsai (and you aren't doing a big root prune, just teasing out roots and oil soil), I'd do it now. Again, if it was mine.

 

[BrianBay9]

Yeah, our weather is not far off yours.....maybe a week or two difference. I've already created some holes in the root mass, but I'll definitely have to keep an eye on it when (if) the rains come. I think repotting for deciduous trees generally starts in late January around here, so definitely working on this one by then. Anyone successful with oak repotting before then?

 

[justBonsai]

Anywhere from late winter to early spring is usually good for repotting. I like to repot my trees around the first or second week of February. I do my cut backs right before the buds start swelling then repot the tree right about when it starts sending sugars up. This is just to maximize backbudding but you can repot earlier. Barry Altshule (Legacy Cork Oaks), the guy I bought my big oak from, says he repots his trees in the winter. But he was repotting large material in big nursery cans with a huge root mass. Usually around December and January he would half the root ball to begin reducing it's size. The concern many have showed with repotting oaks is death from transpiration loss. Many of the oak "pros" here have advocated for defoliating your oak when repotting. It prevents transpiration stress and makes recovery better.

This may not be necessary but I always tarp my oak trees after repotting to preserve humidity and to ensure a quicker recovery. I have also done a partial repotting on my oaks in September. All of my oaks usually throw out a lot of growth late summer to fall but one of my trees appeared to be sulking. The root system was stressed a lot this summer not being properly watered when I moved and having a lot of muck from the center of the root ball trapped in the pot. I pulled it out of the pot, removed all the mucky soil and cut away dead root areas. The tree did just fine and did not react poorly at all. It is also key that the tree was dormant coming out of a recent heat wave and not sending new growth.

I'd say you'd be safer repotting around late January as oaks are more finicky than other deciduous species. If your tree is not sending out any new growth at the time you can do a partial repot right now. Then do the full repotting come by late January to early February. I would not bareroot it though and hose it down if you choose to repot right now.

I think winter may be a bit risky. If you do a major repotting in Nov/Dec you should also cut back a lot or do a partial defoliation to minimize transpiration stress. The thing is oaks do not send out new growth until February so I'm not sure how it would react to a defoliation in the middle of winter. Maybe others can chime in more too.

 

[BrianBay9]

Thanks bleumeon. Growth is not vigorous on mine, but I am getting new growth now. So this one will need to wait. Thanks for the transpiration info.

 

[milehigh_7]

When the buds start moving

 

[jquast]

At Midori, JT does recommend transplanting Live oaks as early as October in the Bay Area. I've repotted Live oaks and Cork oaks in Oct/early November and had good growth responses with them in the Spring. I have noticed that when oaks are repotted in the Spring, they tend to stall a bit and not put on much growth until the next year.

http://www.midoribonsai.org/october-2016/

 

[Bonsai Nut]

I repot in late winter / early spring - which for me in Southern Cal is around late January, depending on the winter. My Chinese elms are my first deciduous to bud and they normally start to bud in mid-February.

If you are worried about it being rootbound, I would slip pot it into a bigger container and surround it with good soil so there is air and water circulation around the root ball.

 

[BrianBay9]

Thanks for the opinions folks. Looks like we have sometime between now and February. My thinking exactly!

Honestly, thanks for all the opinions. I'll have to decide how cautiously to proceed.

 

[sorce]

@BrianBay9

. I recently bought a Q agrifolia (Coast Live Oak) that is seriously root bound

A Lotta BS if your post 542 doesn't include some pics.

I mean, it's good to know if I ever make that .00005% chance move to San Francisco my CLO repotting
Will be successful....

But .....

Sorce

 

[BrianBay9]

OK, OK.....pics coming

 

[BrianBay9]

OK, OK.....pics coming

I can't pry the root ball out of the pot without significant force so I can't show roots. I'll leave that for the repotting.

 

[justBonsai]

I can't pry the root ball out of the pot without significant force so I can't show roots. I'll leave that for the repotting.

That's a nice piece of oak, I like it a lot. The tree appears to be healthy, is there a reason you want to repot earlier?

 

[BrianBay9]

That's a nice piece of oak, I like it a lot. The tree appears to be healthy, is there a reason you want to repot earlier?

It's not as vigorous as I would expect, it's clearly died back at the top, and the roots are so tight I can't push a chopstick into them. I've cut a few holes, fertilized, and as the rains come I'll keep the pot tilted to drain better. I'll keep an eye on things and hopefully can wait until late January.

 

[Arizona bonsai]

It's not as vigorous as I would expect, it's clearly died back at the top, and the roots are so tight I can't push a chopstick into them. I've cut a few holes, fertilized, and as the rains come I'll keep the pot tilted to drain better. I'll keep an eye on things and hopefully can wait until late January.

How did the repot work out? The reason I ask is I have an extremely root bound live oak that I am wanting to transition to smaller, shorter pots. I have moved it into this smaller pot a few months ago buy cutting down vertical through matted circling roots. Bonsai soil was filled in on edges & it seems to be doing ok.
I am unsure of how much roots can be removed & when to do it. The pics are as it is now

 

[BrianBay9]

Its done well....apparently needed the repot and steady feeding. Here's a pic from this morning. Its had one cut back already this spring, and is probably ready for another.





As far as when to repot, late winter would be best, but back in 2017 I think I repotted in December. Of course we don't have much of a winter at all but neither do you. I'd be cautious about doing much of anything heading into the furnace of your summer.

I've not really faced your root issues before. Almost all of mine have been collected with few roots, so I've grown them out in pretty small pots and not had to reduce the root ball. But from collecting I can tell you that a healthy CLO, in the right season, will bounce back from losing virtually all feeder roots. You don't want to go that far because you'll lose a year while it grows roots back. But they should take a pretty healthy root pruning and be OK. In winter.

 

[milehigh_7]

How did the repot work out? The reason I ask is I have an extremely root bound live oak that I am wanting to transition to smaller, shorter pots. I have moved it into this smaller pot a few months ago buy cutting down vertical through matted circling roots. Bonsai soil was filled in on edges & it seems to be doing ok.
I am unsure of how much roots can be removed & when to do it. The pics are as it is now

The best time to repot live oaks is just as the buds are pushing.