Repot natives

[wattynine]

Shibui, excellent post but I would like to get back on topic, and it has me questioning my methods.
I have been in a habit of repotting my natives pretty much when I do conifers, late winter, for what I get of it, but around August, ready for our early spring. I can't say my trees have suffered with the different roster as far as their immediate health, so may I ask, seasonly is it better to repot natives at the heat extreme timing of their dormancy, so for me more likely Dec-Jan?
I also trim and repot at the same time so the second question; is my trimming at this time (late winter) and I go hard, affecting my growth/ flowering, as I have had poor flower results two years in a row?
Interested in your views,
Thanks in advance
Watty

[shibui]

Your climate is very different to mine Watty. If I root prune most of the natives I grow in winter they die pretty quick. Now that I have learnt to root prune when they are actively growing they seem to do far better. Mind you there are a few species that have objected to this treatment so maybe natives are not all natives if you get my drift.
You will not from the above that I am not aiming for dormancy to repot natives. It seems to me that summer dormancy (at least in cultivation) is a myth. I am repotting when they are actively growing and this seems to work.

Your contribution re timing of repotting in QLD is very welcome. If others have any experience to add please do so. We should also start to add species names to the observations to get even better data from this.

re flowering: Again, trying to regard all natives as the same is just plain wrong. Some natives flower on the tips of last year's growth (callistemon) - these need to be left untrimmed in order to flower just like the exotic azaleas; some flower on older wood so they should flower whether you prune or not (I have a hakea that flowers all along the trunk on very old wood). I'm sure there will also be some that flower on new spring growth so winter pruning should not affect them but spring pinching would reduce flowers - think crepe myrtle as an exotic equivalent.

[shibui]

Just for you Ryceman - repotting the callistemon:

repot callistemon 2016 12 1.JPG

Procedure is much the same as pictures already posted except that it is easier to cut around the edges of the root ball then cut the base second.
Here it is back in the pot after trimming so you can get some idea how much I cut off.

repot callistemon 2016 12 2.JPG

and underneath. I've trimmed up as far as the rock. You may be able to spot it poking through the roots in a couple of spots.

repot callistemon 2016 12 3.JPG

That means there is not really very much roots left. The rock takes up most of the remaining root ball.

repot callistemon 2016 12 4.JPG

No point in wiring this one into the pot. It won't go anywhere with that great heavy rock holding it down.

The pot is quite shallow so I could only get about 1/2 cm of mix in the bottom of the pot.

repot callistemon 2016 12 5.JPG

repot callistemon 2016 12 6.JPG

Refill the pot with mix then replace the gravel

repot callistemon 2016 12 7.JPG

That's supposed to look like a river running past the tree

Finally I trimmed a couple more long branches, removed a couple more where they are a bit crowded and rubbed off the rest of the new buds shooting from the trunk then watered it in well.

repot callistemon 2016 12 8.JPG

[Ryceman3]

Awesome. Thanks for the description and pics, both help to explain your process beautifully.

That is a pretty decent root reduction, the Callistemon I got from you has begun to bud after its cut back a few weeks ago so I think I may get "involved" with the roots once they have set... although I'm not sure I'm game to cut that hard! We'll see...
Is there any specific aftercare you employ after a repot like this?

Thanks again for the post... very helpful and much appreciated.

[shibui]

You can see that this callistemon, and all others that are repotted here, went back on to its display stand which is in full sun all day. This one does not even have other trees nearby to provide shade. Yesterday and today are overcast and cooler which is probably helpful.

In the interests of full disclosure I can report that I have had a couple of adverse reactions among the natives I repotted a couple of weeks ago. Out of nearly 100 trees repotted I have had 3 probable deaths and a couple more with browning leaves .

Leptospermum rupestris did not like it at all and I suspect it is dead. This is the first repot for that species here and does not bode well for the species as bonsai. It has also been a very slow grower so I probably won't try it again.
One of the Alocasuarina zephyra also went brown soon after repotting but another one is still looking healthy. Other Alocasuarinas have occasionally died after repotting so if anyone has any ideas for me I'd be pleased to hear.
One of the Melaleuca teterifolias also looks pretty dead. These had pretty sparse roots when repotted and ended up with virtually no feeder roots at all. Another one looks happy.

Some that I transferred into bonsai pots went brown but I think it looks like they will pull through though maybe some branches will not survive.
This is Kunzea parvifolia. Cutting grown and in a training pot for around 10 years.

repot natives 2016 12 5.JPG

A couple of weeks later it is looking more green and appears to be growing again.

repot natives 2016 12 6.JPG

The other one I potted up is a Leptospermum, probably M. decussate. They have been very resilient while in training and shoot on old wood when cut back. Nice small leaves and flowers too.

repot natives 2016 12 4.JPG

Now, a couple of weeks later it has some healthy green growth and looks like it will recover.

repot natives 2016 12 7.JPG

My little Banksia integrifolia has been in the bonsai pot for a couple of years without any problems but after repotting most of the leaves turned brown. It has not got worse and there is still enough green to indicate that it will recover.

repot natives 2016 12 2.JPG

[Robsterios]

Neil/Shibui & Others - A question if I may.. Once the weather gets right into Summer and hot weather, such as now, is there a cut off time when we should hold back on re-potting? There's a couple tree's I've missed and don't really want to leave until next season. It's only the last couple weeks where Summer has really kicked in here in Vic. as you know, it's been like the longest Spring..!!

[shibui]

Are you talking about natives Rob? What species?
I've already stated that I have repotted most of my natives in November and December for quite a few years. I have had some failures but not usually associated with hot weather I think, more to do with the species? The vast majority just go on growing, usually better than before repotting. I have, however lost way more by not repotting root bound natives. They can get very hard to water after a couple of years in a pot.

Trials I have done indicate that banksias can be root pruned Nov-Feb here, does not matter what the temps. Callistemon, Melaleuca, Kunzeas, Leptos(some species), Xanthorea, Eucs, ficus have all been repotted regularly in December whatever the temps.
We do get warmer and drier than Melbourne but not as hot as some other parts of inland Aust.

You will need to be comfortable with the concept before proceeding with summer repotting.

[Ryceman3]

Thanks shibui,
The candid full disclosure is probably as important as the complete success stories so that extra info is much appreciated... I'm thankful my repot count is well below 100 (for now), but I reckon I'd be happy with your strike rate if it was. I can't help thinking that Aussie natives generally seem very fickle when it comes down to it but I guess with so many varieties from so many different climates/environments etc they can't all go into the same basket. In the end (and with limited experience) what your gut tells you is just as important as anything else.
And while your gut is trying to figure out what to say...
Cheers

[Robsterios]

Yes Neil. Aus. Natives... I have a Bukkia.. (not spelled correctly) and some native Myrtles to pot up... I've also got a Casuarina group planting where one has karked it so want to replace. I've not had great luck with the She'Oaks. I've got 2 forest plantings now and have lost one or 2 in the group on both plantings. I found that if one needs to chop into woody solid roots in an effort to get them into a shallow enough pot, they don't like it and just curl up. Seems ok if the roots are fine and fibrous. Just wasn't sure if I should rip the other forest apart to replace or wait until next season... I think, based on your advice, I'll do it this season..
thanks, Rob..

[Rory]

Regarding only casuarinas... both allo and casy:

If the roots of the tree have never been cut, (nursery material) then I usually cut back the foliage/trunk at the start of its strong growth in spring. (Depending on the persons location) this means as soon as the tree is starting good growth for the season in spring. Then I wait until the new growth appears after the cut back (it should be about up to 2 weeks for new growth to appear after a heavy trunk chop or cut back). Then I let the foliage grow for about 3 weeks to toughen up and harden. Then... I perform root work. But if this is the first root work, make sure you leave fibrous root on it, and if you have too much foliage on it once you have reduced the roots, you must get rid of more foliage to appropriately proportion the remaining roots, otherwise the remaining roots won't be able to support the foliage and it will die back. I also try to safely remove most of the old soil, otherwise it won't get watered properly afterwards.
Now the most important thing is to make sure the tree is WELL watered for the next 3 weeks. Don't change the location of the tree. The tree should have been returned to exactly where it was originally, preferably full sun to start with.

I actually won't root prune casuarinas any more unless it is the strong growing season for my area.

Now, for a tree which has been root pruned before, I tend to go a bit harder on the roots, but only if the tree was healthy, lots of foliage and putting out new growth.
I reduce the roots with a hose constantly keeping the roots wet during the process. I remove all the old soil (as best as possible without damaging the finer roots) and cut off heavy roots. Once I have reduced the roots then I again reduce the foliage to the same proportion for the remaining roots to adequately feed the tree. This is hard to explain the proportion but for a novice just take off the same PERCENTAGE for both. The tree goes back to the same full sun as before.
Again, make sure the tree is WELL watered for the next 3 weeks.

Don't try anything fancy like exposing roots after a repot. This is not the time for this.
Check for curl grubs during this repot, as the tree has had a root prune before so it should be used to having the soil washed off already.

Most casuarina like fairly well draining mixes, and prefer full sun. The only real exception to this is glauca which can tolerate heavy mixes but it still wants full sun. HOWEVER I still put about 3 handfuls of slow draining mix around the immediate base (close to the feeding roots near the base of the trunk) for insurance purposes against very hot and windy days. This mix should stay wet slightly longer than the main soil so if it's 40 degrees and windy, this will keep the tree alive until the next day.

So I am not so focused on the "time" of year when I repot casuarina, but I place the emphasis on when the tree is pushing out strong growth for me. Usually this is about October / November in my area but I won't repot or cut back the tree unless I see strong growth, which sometimes means waiting more months. Since applying this philosophy I have not lost any casuarina for quite a few years now.

Just remember if you cut back the trunk prior to a repot, don't cut below the foliage on torulosa or littoralis. It's not really a problem on the other species.
Also, remove proteoid roots which can often develop on neglected littoralis.

If you let a casuarina dry out after a root reduction, you can usually give it its last rights.

Interesting point to note though: if you accidentally let a casuarina badly dry out for any reason during the year, try to remove as much unwanted material immediately on the day or the very next day after drying out. It may increase the chances of it shooting back down low. This last point is simply an observation and not something I want to test, but it seems to increase the chances slightly.

[Robsterios]

Thanks Rory...really good info and techniques to consider.

[shibui]

Great info Rory. Thanks for adding it into the mix. I will be bearing all that in mind when I next repot sheoaks.

[shibui]

The Callistemon has not looked back since I cut the roots and repotted. The new shoots I left intact just kept growing and lots of new ones sprouted and have also grown strongly. It now appears to be as dense as before I pruned so may be time to thin it again.

callistemon root over rock 2017 1 1.JPG

As usual it has also produced lots of shoots way back on old wood. I keep rubbing them off but more grow.

callistemon root over rock 2017 1 2.JPG

callistemon root over rock 2017 1 3.JPG

The new shoots are also growing strongly where they are supposed to be

callistemon root over rock 2017 1 4.JPG

This is where callistemon bonsai growing gets a little frustrating. To get flowers in spring I need to leave the shoots unpruned but unpruned shoots look untidy and puts the design of the tree out of shape. I'm just about to start feeding this, and other spring flowering species, with higher K fert to promote flower buds.
Any thoughts from experienced callistemon growers? Does K help callistemons flower and when to apply it? What is the latest you can prune and still get flowers in spring?

[Steve B]

That's a healthy looking bottlebrush! It's clearly "in a good paddock" if it's shooting back that vigorously.

In regards to cutting them back I read one of Pup's pieces where he suggested doing the last structural prune in March and then letting them run until flowering in November(ish). Worked pretty well for me in Sydney for both Mels and Callistimons - although I struggle to resist the urge to prune them back as they can get pretty bushy. I haven't tinkered with specific flowering fertilizer higher in K, but that's mainly as I'm still pushing for structural growth and not in the state of refinement you are with this one.

Be interesting to see if you get on responses on the use of higher K ferts to promote flowering so I can thieve the knowledge and apply it in a year or two.