AusBonsai

Hi guys,

Just needs some advise if possible, or I fear this little guys destined for a prolonged trip to the green bin.

I purchased this pre bonsai Banksia Seratta a couple of weeks back in early April, at the Aus Native Symposium in Melbourne (Thanks Neil).

As the last couple of weeks have gone by I'm noticing more and more leaves turning yellow and then eventually brown... As the leaves are already quite stiff on the Seratta I am unsure if it is under or over watering that is causing this, let alone if its due to water at all. When it first came home I reduced its height by approximately 1 quarter for ease of movement, but have not touched any other branches.

Its positioned in full sun and is not under cover, receiving full rain (were beginning to get a bit more now in Melbourne but definitely nothing excessive).

All advice would be greatly appreciated!


Cheers,
Pearcy.

Nothing wrong with the tree. It is just in the process of shedding old leaves.

Keep it in full sun and there should be no dramas,

Grant

Grant Bowie wrote:Nothing wrong with the tree. It is just in the process of shedding old leaves.

Keep it in full sun and there should be no dramas,

Grant

Thanks Grant, You've put me at ease some what as it's my first Banksia.

The thing that was concerning me is that even its smallest leaves are doing the same not just the larger ones? Granted the more sun each leaf gets the bigger it will be.

Cheers,
Pearcy.

The thing that was concerning me is that even its smallest leaves are doing the same not just the larger ones?

Smaller leaves are often also the oldest ones. When a shoot first starts to grow the leaves are usually quite small with each new one that grows getting a bit bigger so often the small leaves are also the oldest.
Look at where the affected leaves are on the branch. Looks like they are the furthest away from the tips so must therefore be the oldest leaves?

They should not be too wet in the mix I use, even with this rain.

I'm pretty sure that Grant is correct with his diagnosis but let us know if it does get worse.

Yep looks perfectly fine and healthy to me.

That's guys the info is greatly appreciated.

So my banksia now has a new problem.

I thought I'd try a new liquid fertilizer so I got my hands on Seasol Powerfeed (the green bottle), as I have only ever used Charlie Carp before that. Seems to me as if the P in the NPK was a little stronger than my novice guesstimating could work out.

The other day I diluted 50ml of Powerfeed into 9L of water and gave all my trees a drink.

In my collection the only natives I wasn't sure about was my dwarf baeckea and my banksia seratta.

The baeckea is going gangbusters, but the banksia... not so much.

About 48 hours later I gave it a check and approximately 60% of the foliage is now a more grey-green compared to the other 40% that is still a vibrant green. A few leaves like the photo attached are a mixture of both.





Is the tree on a slow decline to the big green wheelie bin? Or is there still a chance it will bounce back? It is now about a week later and not alot has changed.

All comments welcome.

Cheers,
Pearcy.

While there's life there is always hope Pearcy. I have seen banksias look a lot worse than that and still recover so keep watering it and cross your fingers.
50 ml powerfeed in 9 litres of water should be ok even for banksia. I think I usually use 90ml in 9l. The problem with banksia is if they have had few nutrients for a while they develop more proteoid roots and are more susceptible so mine that have been regularly fed can tolerate higher levels without any harm than a plant that has not been fed.

Your tree should have a pretty dense mass of roots by now. I find that they need repotting every year or 2 at the most or the root ball gets so full of fine roots that water cannot soak in and they end up getting too dry and dying, even if you water properly. It is probably nearly time to repot banksia. I'll be doing mine late Oct or some time in November.

Thanks for the help Neil. Yeah I wasn't thinking it was too strong either but I also don't have the experience to know for sure so thanks for the clarification.

I was already planning to repot when we get some consistently warmer days as the water doesn't penetrate always already, it will be reported consistently every 12 months. I'm currently soaking it in a tub for around 15 minutes once a week to get the water right in there and dampen the soil.

Would you suggest no ferts for a while now so it can recover? or charge on and get it used to it with a lighter dose? I've scratched back the cambium higher up and is still green.

No fert until it shows signs of recovering I think. Everything else sounds OK

In need of some Iron Chelates.

Cheers Pup

I feel 50ml in 9 litres may be a bit strong for the Banksia; especially if it was the first feed for the season and especially for the Banksia if it had been hungry and un or underfed previously.

Always a slow build of ferts for Banksia is proven to be effective; whereas a big dump of any fertiliser can be hazardous for Banksia.

Grant

Pup wrote:In need of some Iron Chelates.

Cheers Pup

Pup do you mean in general? Or specifically in order to fix the problem caused by the over fertilization?

Grant Bowie wrote:I feel 50ml in 9 litres may be a bit strong for the Banksia; especially if it was the first feed for the season and especially for the Banksia if it had been hungry and un or underfed previously.

Always a slow build of ferts for Banksia is proven to be effective; whereas a big dump of any fertiliser can be hazardous for Banksia.

Grant

Hi Grant. Can I ask what sort of ratio buildup you would suggest and over how long?

It received Charlie Carp every 6-8 weeks over winter at around 100ml per 9L. It then received the same dose at the start of September and again in mid September. The Powerfeed was then used at 50ml start of October.

I thought it might have been OK but knew I was probably pushing the limit haha. Only way to learn is it give it a try.

Pearcy001 wrote:

Grant Bowie wrote:I feel 50ml in 9 litres may be a bit strong for the Banksia; especially if it was the first feed for the season and especially for the Banksia if it had been hungry and un or underfed previously.

Always a slow build of ferts for Banksia is proven to be effective; whereas a big dump of any fertiliser can be hazardous for Banksia.

Grant

Hi Grant. Can I ask what sort of ratio buildup you would suggest and over how long?

It received Charlie Carp every 6-8 weeks over winter at around 100ml per 9L. It then received the same dose at the start of September and again in mid September. The Powerfeed was then used at 50ml start of October.

I thought it might have been OK but knew I was probably pushing the limit haha. Only way to learn is it give it a try.

I use Powerfeed at 30ml per 9 litres usually; and do a half strength once or twice at the start of the season to ease it in.

If you had been fertilising through winter then I don't know what the problem is.

Grant