Banksia integrifolia 'sentinel' question - Grant? Squizzy?

[Rory]

On a visit to Cumberland State Forest Nursery (now plants plus), I browsed their Banksia stock. I was intrigued by a new variety I had not heard of called:
Banksia integrifolia 'sentinel'.

The nurseryman says he believes they are about 12 years old - the variety that is. He believes it was grown from propagating smaller and smaller leaf varieties until they came up with this. It only gets about 2m tall and has much much smaller leaves than the normal integrifolia.

I presume this will make great material for bonsai, but just wondering if anyone knows anything about this....Grant, do you know much about these?... Squizzy, Are you still growing any, how have you gone with them?....or anyone else growing them?

https://austraflora.com/project/banksia-sentinel/

I read Grants thread on integrifolia, but didn't notice any mention of this variety....
viewtopic.php?f=69&t=812

I read a thread questioning integrifolia in general as shohin, and squizzy only touched base on them....
viewtopic.php?f=138&t=14188&hilit=banksia+sentinel

They had many others, but none of them were even close to the size of this one. I paid a bit more than I would have liked but considering Banksia is my 2nd favourite genus, I couldn't resist.
I paid $69 but I am very happy with it.

I will probably just treat it the exact same way as I do with my many other normal integrifolia unless anyone on here knows anything else. We don't really get harsh winters on the central coast, and all my integrifolia have shot new shoots about 6 weeks ago, but to be on the safe side I'll repot and look at the roots perhaps in mid spring. I cut it back very hard as integrifolia normally shoots from wherever you cut, no matter how low.

This was the specimen I bought:

[shibui]

The nurseryman says he believes they are about 12 years old - the variety that is. He believes it was grown from propagating smaller and smaller leaf varieties until they came up with this. It only gets about 2m tall and has much much smaller leaves than the normal integrifolia.

I'm sure that is a possible route for developing this variety but in my experience most native cultivars are selections from natural plants rather than concentrated breeding programs. The latter takes many years and lots of space and effort. Finding natural variations is far quicker and easier. Whenever we are away I keep my eyes out for any individual trees that appear to be slightly different from the main population. I have several different small growing banksias raised from seed collected from dwarfed plants, most from coastal headlands and clifftops. I have at least one that is a small leafed integ variety - because it is a seedling I am entitled to give it a variety name but have not done so yet. All mine are treated the same as the standard varieties.

I the past 10 years or so there has been a proliferation of new varieties in native plants suitable for gardens, mostly concentrating on smaller varieties that will have a wider appeal because they fit into smaller suburban gardens. Every year there seems to be another couple of small banksias being offered, some of which appear to be very little different from those that have been offered before.

In my experience dwarf varieties have some drawbacks as bonsai. They are usually much slower to grow and develop than the standard types and are often less hardy however I'm still persisting with several and they may have a special place to develop smaller bonsai where growth rate and size is less of an issue.

[Rory]

The nurseryman says he believes they are about 12 years old - the variety that is. He believes it was grown from propagating smaller and smaller leaf varieties until they came up with this. It only gets about 2m tall and has much much smaller leaves than the normal integrifolia.

I'm sure that is a possible route for developing this variety but in my experience most native cultivars are selections from natural plants rather than concentrated breeding programs. The latter takes many years and lots of space and effort. Finding natural variations is far quicker and easier. Whenever we are away I keep my eyes out for any individual trees that appear to be slightly different from the main population. I have several different small growing banksias raised from seed collected from dwarfed plants, most from coastal headlands and clifftops. I have at least one that is a small leafed integ variety - because it is a seedling I am entitled to give it a variety name but have not done so yet. All mine are treated the same as the standard varieties.

I the past 10 years or so there has been a proliferation of new varieties in native plants suitable for gardens, mostly concentrating on smaller varieties that will have a wider appeal because they fit into smaller suburban gardens. Every year there seems to be another couple of small banksias being offered, some of which appear to be very little different from those that have been offered before.

Thanks Neil,

I would say you are probably right. That sounds like common sense in regards to the history of this small leaved version.

In my experience dwarf varieties have some drawbacks as bonsai. They are usually much slower to grow and develop than the standard types and are often less hardy however I'm still persisting with several and they may have a special place to develop smaller bonsai where growth rate and size is less of an issue.

oh poo! I hope not, but thank you for the advice

[squizzy]

Hi Rory,

I haven't put much effort into my "sentinels" so its hard for me to say whether they grow slower but in saying that they haven't done a lot where others of mine have. ( I really should try harder ). I think I have 2 that re still in 6 inch. I should get them out and push them a bit hey. For me the advantage with sentinels is the short inter node length as oppose to the leaf size.
.
I do agree with what Neil has said. For me the biggest advantage is the chance of finding better stock of straight integrifolia. I have found some great stuff in the last year. I have just got to get the feeding of them sorted. I air on the side of caution though Grant says it can be heavier but it must be done gradually.

I think yours is a great starting point though. If your game enough at the price you've paid I would cut it hard ( no leaves left from my experience) It should explode with shoots.

Cheers

Squizz

[Grant Bowie]

Hi all,

In general I try to stick to the species as it is always more vigorous which gives us quicker results and better long term longevity. However I would also encourage experimentation always as you just never know what will become of it.

I gave a talk/demo yesterday on natives in Sydney and once again focused on Banksia, as well as Calitris, Kunzea and Leptospermum.

Of all the Banksia I do prefer the Integrifolia and its 3 species and some cultivars look very promising indeed.

I haven't tried the selection you mention but will keep an eye out for it.

Re fertilising you can just feed as per all your other trees with good results.

Grant

[Rory]

I do agree with what Neil has said. For me the biggest advantage is the chance of finding better stock of straight integrifolia. I have found some great stuff in the last year. I have just got to get the feeding of them sorted. I air on the side of caution though Grant says it can be heavier but it must be done gradually.

I think yours is a great starting point though. If your game enough at the price you've paid I would cut it hard ( no leaves left from my experience) It should explode with shoots.

Thanks squizzy. I'd love to see pics of yours over time. Yes I understand what a lot of people say about dwarfed varieties, but I just can't resist.

Yeah, I loved the base of this banksia. I cut it back really hard, to about 15cm above the soil and intend on having a triple trunk specimen. However, I cut back the 3 main trunks hard but left quite a few shoots with leaves on them around the base. This was not to have sacrifice branches, but I have found that in the past when I cut back hard I find that Banksia recover much faster and better if I leave a lot of foliage on the tree. I might be an idiot and the science is wrong but I have not had a problem so far with this method and will continue leaving foliage after heavy cut backs until I encounter a problem.
Feel free to inform me if this is stupid for whatever reason though as most people seem to say the same as you.

I am scared to do a serious root prune now though. I might either wait until late spring when the tree has recovered well and put out strong new growth to root prune. Do you think that might be a bad idea Grant / Squiz? Or when would you recommend the first root prune? I'm just not experienced enough with Banksia to make these calls - having only been into them for a few years now because of their requirements for a lot of sun.

I gave a talk/demo yesterday on natives in Sydney and once again focused on Banksia, as well as Calitris, Kunzea and Leptospermum.

Grant

I would have loved to have heard this. I am slowly building up a collection of leptos now due to their seemingly better tolerance against myrtle rust than others.

Of all the Banksia I do prefer the Integrifolia and its 3 species and some cultivars look very promising indeed.

I haven't tried the selection you mention but will keep an eye out for it.

Re fertilising you can just feed as per all your other trees with good results.

Thanks for the advice Grant. I am very optimistic as the nurseryman says it was quite hardy and they have had good success with them. However time will tell, as nurserymen don't generally cut back roots heavily though.

[Grant Bowie]

Do a moderate root trim the first time, then harder the second time. You are training the root system as much as the rest of the tree, so you can't do everything the first time around with safety.

Grant

[Rory]

And yes it it a good idea to leave lots of foliage on the tree over winter and also during and after root trimming, they seem to recover quickly.

Grant

Thank you very much Grant. I will also take it easy on the first root prune. I appreciate your input.

[squizzy]

Hi Rory

Not much at all to show on my two. They are still in 6" pots and will definitely need a pot up this year. My main problem is too many plants not enough time.

I will say a few things I have noticed the past week since you brought up the thread. They are just shooting into spring now here on the northern beaches of Sydney. They seem to shoot a heap from one spot and I have let a few go in the past which has meant over fattening of these unions. Pick the one you want early and rub the others off.

image.jpeg

[Rory]

Hi Rory

Not much at all to show on my two. They are still in 6" pots and will definitely need a pot up this year. My main problem is too many plants not enough time.

Thanks for the pic. I very much have the same problem.

I will say a few things I have noticed the past week since you brought up the thread. They are just shooting into spring now here on the northern beaches of Sydney. They seem to shoot a heap from one spot and I have let a few go in the past which has meant over fattening of these unions. Pick the one you want early and rub the others off.

I would say that is the same for all my Banksia integrifolia in general. But I've only been growing them for a few years now.

I took a closer look at the top soil over the weekend and oh my gosh...I am excited but I know I'm in for a world of hurt when I attempt the first repot of this large specimen above ; when I water it, the water pools at the top for about 5 minutes before it finally seeps down below the surface. I presume it is going to be very, very pot bound.

So this may be more of a 5 year plan for working on the roots. As soon as the new growth shoots from the heavy cut-back and hardens up a bit I plan to repot.

[Rory]

Well.... the roots weren't as badly pot bound as I thought. It still took quite a few hours to work them out a bit though. I couldn't be bothered working my way in, so I just used a bow saw and cut the bottom half of the roots off. I cut it back about a week after I bought it, and today have cut the roots back. It shot all over a few months ago. I didn't find any proteoid roots, and will now allow it to recover for a few seasons at least.

After I took it out of the pot:

Banksia1.jpg

After the roots were cut off, worked and potted up into an orchid grow pot.

Banksia2.jpg

After the roots were cut off, worked and potted up into an orchid grow pot.

Banksia3.jpg

[Rory]

Well that was money well spent. Dead.

Both integrifolia sentinels I bought died during the extreme heat wave we endured. They were not dried out. I can't explain it other than intolerance to extreme heat. They were well watered.

All my normal integrifolia are alive and loved the heat. But the sentinels just carked it.


It's a shame because they had the cutest foliage and nice gnarly bark.

[dennismc]

Rory sorry to hear of the death of your Banksias. From much botanical research and 30 plus years working with Banksias it is my experience that all Banksias need to stand in water during the hot weather. In Sydney for example that is from he beginning of December to the end of March the hot weather. As a result you will get much increased rate of growth and a much better +resistance to the heat.

While this may seem counter to what one would expect there are quite clear reasons for this scientifically.

A considerable number of students at the School of Bonsai have followed this regime and all report its complete success.

Dennis Mc

[Paul W]

Hi Grant,Squizzy or Dennis
Would it be too late to repot a B. Integrifolia in Sydney tomorrow, it has heaps of new growth on it and I have a new pot for it, so I would probably have to do a bit of root pruning to fit it in, with the weather like it is up here with showers and the high humidity,should be alright I would imagine as everything is growing like crazy at the moment.
Will see everybody at the market on Sunday,

[Grant Bowie]

Hi Grant,Squizzy or Dennis
Would it be too late to repot a B. Integrifolia in Sydney tomorrow, it has heaps of new growth on it and I have a new pot for it, so I would probably have to do a bit of root pruning to fit it in, with the weather like it is up here with showers and the high humidity,should be alright I would imagine as everything is growing like crazy at the moment.
Will see everybody at the market on Sunday,

Should be OK.

Give it a light top prune only so that it still has plenty of foliage left on it. this keeps the root system exercised and not die form root rot; the only usual suspect of death in B integrifolia .



Cheers,

Grant
Grant