BANKSIA INTEGRIFOLIA AS BONSAI

[Grant Bowie]

General update after questions re Banksia during a talk on Natives yesterday.

Over the past many years in regards to B integrifolia I have been doing the following.

Potting mix. 4 parts Diatomite, 2 parts zeolite, 2 parts mini pine bark nuggets, 2 parts coconut fibre and now 1 part Akadama.

Fertilising, still some but not excessive use of Osmocote standard (not Native) when repotting, Powerfeed and Seasol every 2 weeks during the growing season.

Use of wire. Yes usually aluminium.

Clip and grow. Also yes.

Hard cutting back. Make sure you leave a big stub, seal the cut and rub off any new buds for about 6 months then reduce or remove the stub. Otherwise you may get some die back into the trunk if you remove a really heavy branch.

Root pruning can be quite hard at the right time of year.

Carving of trunk. Yes. I had a tree die back and then strongly recover which has now got a beaut hollowed out trunk.

Re Banksia serrata. I avoid using wire on them.

Grant

[Rory]

Fertilising, still some but not excessive use of Osmocote standard (not Native) when repotting, Powerfeed and Seasol every 2 weeks during the growing season.

Hard cutting back. Make sure you leave a big stub, seal the cut and rub off any new buds for about 6 months then reduce or remove the stub. Otherwise you may get some die back into the trunk if you remove a really heavy branch.

Root pruning can be quite hard at the right time of year.

Hi Grant,

As always, the forum is indebted to your advice, I thank you immensely and for starting me on my love of Banksia in particular after reading this thread.
Can I ask you why you don't recommend Osmocote native fert. I have been using Osmocote native slow release fertilizer for about a year on my Banksia now. I am guessing it might be the small bluish pellets that break down very quickly? I have noticed that if the small blue soft pellets are accidentally left and catch on a thin branch of .... any genus for that matter, it often burns the shoot and sometimes kills it. Otherwise please can you elaborate why you don't recommend this.

I use Powerfeed for natives as well. As per your recommendation, when I started with them I gradually built up the regime and didn't have any problems. However the first time I used the powerfeed I accidentally left a bit on the foliage and it burnt areas of the foliage on all my banksia, but never really bothered the tree and it happily 'powered' on, so to speak. I haven't fertilized them since repotting about a week ago, and I presume it might be safe to wait a few more weeks before fertilizing slowly again as I cut back the roots very hard on them all.

And thank you also about your advice on leaving a lot of foliage over winter. This advice was gold for my Marginata trees.

Would it be safe to say that when most of the Banksia put forth a tonne of new foliage that it would be safe to do a heavy root prune, as I did this a week ago with most of mine because the whether is warming up a lot here in Gosford.

[JaseH]

I have noticed that if the small blue soft pellets are accidentally left and catch on a thin branch of .... any genus for that matter, it often burns the shoot and sometimes kills it.

I think those blue pellets are the added water wetter component - hence they break down quickly. I'd assume a concentrated dose surfactant may not be good for plant cells?

[Grant Bowie]

Years ago I did a side by side test with trays of banksia. I applied Osmocote on the surface of both trays of banksia. The ones with standard Osmocote grew better than those with Naive Osmocote, so since then I have not felt the need to use Native Osmocote on my Banksia, and therefore neither on other natives.

In Sydney it would soon be potting season for Banksia and other natives but here in Canberra I will leave it about another 8 weeks.

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

[Rory]

Thanks heaps Grant.

[Thymetraveller]

I was at the demonstration on Sunday. It was inspirational, entertaining and informative.

I had been avoiding working with natives, as they seemed to need a lot of "special treatment," but now I find myself with a good excuse to get some more trees.

Thanks Grant!

I snapped this during the dem: a master works on an extraordinary tree...

GBBanksia.jpg

[Grant Bowie]

Worst view possible though; the back of the tree and my face.

Oh well. Anyhow glad you enjoyed the demo. I am looking forward to this tree putting out some growth so I can then lightly trim it and possibly repot soonish.

Grant

[BikesandBonsai]

Hi Grant, just a quick quiry. what is your dilution ratio with powerfeed when fertilising Banksia. Also have you tried the Bush Tucker pellets?
Thanks

[shibui]

I've also started using standard osmocote on banksias. Started, like grant, with a side by side trial and had no problems so I've been using it since.
I'm not sure what you're getting at with this statement Rory -

I haven't fertilized them since repotting about a week ago, and I presume it might be safe to wait a few more weeks before fertilizing slowly again as I cut back the roots very hard on them all.

fertilising banksias after root pruning is the safest because you will have removed most of the proteoid roots and they are far less susceptible to P at that stage. By withholding the fert there is a risk they will grow more proteid roots so when you do fertilise the risk of overdose is higher. Personally I have not seen adverse reaction from fertiliser applied to recently root pruned trees of any species (Osmocote in the mix starts releasing from day 1). This may be another myth??

[Grant Bowie]

Hi Grant, just a quick quiry. what is your dilution ratio with powerfeed when fertilising Banksia. Also have you tried the Bush Tucker pellets?
Thanks

For all trees both native,exotic, deciduous, evergreen. I use 30ml per 9 litres which is a ratio mentioned on the bottle and I have followed for many years.

I haven't looked at pellets recently but would consider them in addition to Powerfeed on double flush Pines like Japanese black pine and red pine.

Grant

[Grant Bowie]

I agree with ShibuiShbui about the fertilising myth. I used to liquid feed through my sprinklers and so if it was reported it would be fertilised.

Grant

[Rory]

I've also started using standard osmocote on banksias. Started, like grant, with a side by side trial and had no problems so I've been using it since.
I'm not sure what you're getting at with this statement Rory -

I haven't fertilized them since repotting about a week ago, and I presume it might be safe to wait a few more weeks before fertilizing slowly again as I cut back the roots very hard on them all.

fertilising banksias after root pruning is the safest because you will have removed most of the proteoid roots and they are far less susceptible to P at that stage. By withholding the fert there is a risk they will grow more proteid roots so when you do fertilise the risk of overdose is higher. Personally I have not seen adverse reaction from fertiliser applied to recently root pruned trees of any species (Osmocote in the mix starts releasing from day 1). This may be another myth??

Thanks Neil. That is good to know then. For new banksia I will build up slowly. For the last 20 years I have never fertilized anything right after a repot, so I guess it might be a myth. I was always told this and never really thought to question it.

[Rory]

Hi Grant, just a quick quiry. what is your dilution ratio with powerfeed when fertilising Banksia. Also have you tried the Bush Tucker pellets?
Thanks

For all trees both native,exotic, deciduous, evergreen. I use 30ml per 9 litres which is a ratio mentioned on the bottle and I have followed for many years.

I haven't looked at pellets recently but would consider them in addition to Powerfeed on double flush Pines like Japanese black pine and red pine.

Grant

Noooo. Really? Are you using normal power feed? I am using power feed for natives and I use 90ml per 9litres of water. Is there a big difference in the 2 types or am I missing something.

On the back of the native power feed fertilizer it recommends 90ml per 9litres for trees. As this is just a ratio I built it up over time for my collection but have not had a problem. Am I still doing something badly wrong ?

[shibui]

When I use powerfeed I use it at the recommended 90ml/9 litres on all trees. No problems, even with slightly hungry banksias.

Note that Grant told me he is very meticulous with fertilising - every second Monday Grant? I'm a bit more unreliable - every 2,3 or 4 weeks when I remember

[Ryceman3]

Note that Grant told me he is very meticulous with fertilising - every second Monday Grant? I'm a bit more unreliable - every 2,3 or 4 weeks when I remember

I stuck a reminder on my phone's calendar... now at least my phone knows when it is time to fert...