AusBonsai

I've just done a root prune and repot on an Atlantic Cedar which I've never done this time of year so not sure how much sun to give them. Is full sun too much?

Any plant which has had its roots disturbed would struggle in full sun.

Can you give a little more info? Is it an established bonsai? Or did you take it from a nursery pot to a bonsai pot? Was the repot harsh with alots of root removed? Or was it a light root trim and back into a bonsai pot?

Depending on the answer and If it was my tree I'd keep it shaded for a week or two while it settled down then back out into the sun. Established bonsai with a light root trim id put it straight back out.

Keels wrote: ↑January 11th, 2023, 1:27 pm Can you give a little more info?

Took a tree from plastic pot and teased out the roots around the root ball and gave it a light prune, about twenty percent of the roots removed and planted it into a ceramic pot, not a bonsai pot, wasn't courageous enough.

Any plant which has had its roots disturbed would struggle in full sun

I have not found this to be totally true. Agreed that some trees do take some time to adjust after summer root prune but others seem to take it in their stride. I regularly repot banksias through summer. Even with temps up over 40 for the week following they go straight back on the bench in full sun and keep on growing.
There's a thread on here somewhere quoting a very experienced grower now deceased who claimed the best time of year to repot cedrus was mid summer. He was even quoted as saying the very best time was the hottest day of the year.

There's also a growing movement by very experienced bonsai growers to summer/late summer repotting for many species. I've seen Grant Bowie talk about repotting old maples in summer here in Australia and many in Europe and America. Not sure whether any of those summer repots are provided with shelter afterward or not.

shibui wrote: ↑January 11th, 2023, 5:40 pm I have not found this to be totally true. Agreed that some trees do take some time to adjust after summer root prune but others seem to take it in their stride.

Yeah when I root prune in spring the trees goes into full sun. The tree needs to make energy to help it recover so I don't get why you would put it into shade, that will just weaken it. Middle of summer however I'm not sure.

one_bonsai wrote: ↑January 11th, 2023, 8:40 pm Middle of summer however I'm not sure.

So why did you do it?
You don’t mention anything that says the tree was stressed and from the pics posted it looks completely healthy, just not sure why you went down a path you aren’t confident with on a tree that is looking fine.

With due care and diligence it is OK to repot cedars in general in summer. I have done so with my longest held Bonsai, since 1975 and its going berserk at the moments and about to have its post Christmas yearly trim.

Grant

I find it really bold to be reporting in summer let alone putting it straight back into full sun. Will play it safe unless my trees are stressed. Agree with the aspect about making new roots and energy, but most of my life I have been taught to keep repotted plants( let alone root pruned bonsai) in the shade straight after reporting and thereafter back in sun once recovered. Keen to see how you go anyway.

You can repot in summer after the leaves have hardened as many trees have a short summer dormancy (kind of) but really, why would you do it unless you had to? If you remove roots, the plant will not be as efficient in water uptake for a while and it would be foolish to place it back in full, all day sun on a really hot day straight after. I repotted a rose today because it was drying out too fast and placed it in spot which will be shaded after noon. It's only common sense.

Ryceman3 wrote: ↑January 11th, 2023, 9:33 pm So why did you do it?

Because there's people doing summer reports with cedars so I wanted to have go myself and see if it's a good option for the future.

Ryceman3 wrote: ↑January 11th, 2023, 9:33 pm
You don’t mention anything that says the tree was stressed

That's because it's not stressed

Grant Bowie wrote: ↑January 12th, 2023, 2:25 pm With due care and diligence it is OK to repot cedars in general in summer. I have done so with my longest held Bonsai, since 1975 and its going berserk at the moments and about to have its post Christmas yearly trim.

So do you put them in the shade straight after the repot?

.

Ryceman3 wrote: ↑January 11th, 2023, 9:33 pm ...not sure why you went down a path you aren’t confident with on a tree that is looking fine.

To get experience with summer repots thus gaining confidence