Acacia experience to date

[EdwardH]

Hi everyone, I was reading through the various Acacia posts and was wondering if people have any updates on growing Acacias as bonsai. There are quite a few posts from around 2009 - 2012 and then they sort of died off (pun intended). So how have those acacias been growing? I am especially interested in anyone who has kept theirs alive for a decade or more. The promising species mentioned included melanoxylon, buxifolia, cardiophylla, prarvissima, aneura, howittii.

[tgward]

I've only heard that most are relatively short lived

[greg27]

I have an Acacia pendula on the go - it's only two years old but I've read it can live for 200 years or so. There are some large specimens in the Adelaide Botanic gardens (it grows easily from seed of anyone's keen!) that seem pretty happy. It doesn't seem to mind having most of its roots chopped off.

[KIRKY]

Had a twenty five year old Howittii, until next doors basketball did it in
Cheers
Kirky

[Starfox]

I've had a couple of melanoxylon in the past, both sadly went south on me. The first one seemed to resent having branches wired downward and would abort whole branches and sections over time. It did this until it eventually aborted itself altogether because I was stubborn and kept on wiring for the look.

The other one have up the ghost after flowering one year. Not sure if it would of helped if I had cut the old flowers off sooner so it didn't spend the energy on seed production or not. Shame as it was lovely when in flower.

The one Acacia I have left is an A. saligna, this seems bomb proof. I have wired a full loop in the trunk and it has no issues with that. Seems to back bud well and thickens up in the pot, could probably get more growth from it if the pot wasn't so small but it is what it is.
Had it roughly four or five years, could probably find out. It was literally hand ripped from the ground as a first year sapling, died back but reshooted next spring and grown on from there.
Roots smell of onions when disturbed too. Still haven't had it flower yet and doesn't look as if it will this year either.

[Keels]

People aren't interested in investing time into Acacias for them to be so short lived.

Acacia Howittii are your most common and very successful in bonsai culture but people play with all sorts of different Acacias.

I've had a couple of silver wattles that i have attempted to produce a half decent trees from. They just ended up looking shari and i got rid of them. They were very uninspiring trees.

My Saligna has been my most successful one to date. It's looking beautiful at the moment. It responds well to hard pruning but the wood is still young so not sure how it will back bud at this stage. It has a nice weeping habit but the leaves are very long.

I'm hoping to give a get my hands on some Acacia leprosa ‘Scarlet Blaze’. Imagine a red flowering Acacia

[MJL]

Hi Edward,
I am really enjoying this group of Blackwoods. (See link below)

Unfortunately it’s not a 10-20 year old example for you but I am finding them responsive and fun - if difficult to reduce lead size. Water loving too.

https://r.tapatalk.com/shareLink/topic? ... source=app


Sent from my iPhone using Tapatalk

[Jan]

Hi Edward,

I've no long term info but am interested in the info posted here as I've just started growing a Cootamundra, an Acacia boormanii and a couple of Acacia
iteaphylla to see how they go as bonsai.

I'll be watching and hoping for some tips

Jan

[EdwardH]

I started a Cootamundra wattle in 2019 and it is powering on though obviously it is still very early days. I have only slip potted it so not sure how it will go next spring when I trim the roots a bit.

Last winter I lost an A. fimbriata. I had it for a few years and it grew quite well handling trimming of roots in spring, cutting back branches with re growth on young branches & trunk anytime in spring and early summer however last year I experimented with repotting in Autumn to see how it would go. Well it went downhill quite quickly. Note to self only repot before it goes into a growth period, i.e. mid spring.

I also started some A. aneura from seed a few years ago. 5 seeds sprouted and grew very well. When I repotted them in Oct 2020, all the soil fell off the roots so they were effectively bare rooted. All five did well for a 2-3 weeks whilst it remained below 30 degrees but once the temps spiked to high 30's/low 40's three plants died within a week or two. A fourth struggled for a about a month before dying and the fifth tree survived with only the drop of a couple of leaves. Was this providence or simply too hot too soon? I don't know the answer. Perhaps some one who has grown this species for some years has an answer.

I grew an A. melanoxylon for about 10 years and it handled slaughtering the roots, too much or too little water, drastic pruning etc. BUT last summer I killed it when I defoliated it and root pruned it at the same time. I believe that by removing the leaves at the same time as root pruning that I killed it. I am certain that had I not defoliated it that the tree would have continued to thrive.

I have 2 reasons for starting this post. The first is that I have read a number of posts of various Acacias which have survived 30-40 years - prarvissima, saligna, howittii. So obviously some species CAN live for a very acceptable time in bonsai culture. BUT and here's the BUT, with so many to choose from and so little data the attrition rate must be very high leading to the usual comments like "you can't grow Acacia's as bonsai or they are too short lived."

The other reason is Rory's series of "Native Trials" posts. As he is trialling many smallish shrubs with small leaves, I assume that they shall struggle to get any girth to the trunk and will probably be fairly short lived, probably only 10-15 years. So IF my assumption is correct (and I do not know if it is) then many of these small shrubs would have similar short life expectancies as many Acacias. I purchased a Phebalium squamulosum last week to trial. I cut off half the roots and it hasn't missed a beat in the mid 30's temp that we experienced a few days ago so that is a promising start. Will the Phebalium displace my love of wattles? NO way Rory!

[GavinG]

Acacias in general: the coast-and-mountains Acacias tend to be pioneer species - fast-growing and don't live long. That said, A. howittii can live for 40+ years, which should do most of us.I don't know any Acacias that reliably shoot back on old wood, but I don't know many species.

I have grown A. genistifolia, but don't rate it - it has no really interesting features, and probably won't last.

P1020772.jpg

I grew a prostrate form of A. saligna for some years - while it looked promising, it gradually ailed and died. More gentle root-pruning, and top-pruning at a different time might have saved it.

Similar for a prostrate form of A. cognata, "River Cascade" I think - it looked promising but is gradually fading.

P1020773.jpg

A. howittii is rightly popular, but for me it needs more root room than I usually allow, and plenty of water.

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The dry-and-arid zone Acacias can live multiple-hundred years, and have great potential for bonsai, but you have to seek them out, usually mail-order. I found A. pendula at Bunnings, only once in ten years - it has a great base, but doesn't develop branch structure in a way I relate to.

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Acacia aneura (mulga) is a great bonsai subject, and survived with me for ten years, but as it aged it did not survive my root-prune+hard top hack habits - I will be gentler on the roots, and prune the top after I know that the plant has survived the root work. I regret losing them. Here's a younger one - great bark early, good angles, and a lovely blue-grey leaf. I haven't been disciplined - I should just have kept one or two leaders each year, and really made a complex trunk, before I started to get foliage complexity. I think I want to get 5 A. aneura tubes each year for the next ten years - they have so much potential.

P1020776.jpg

Great textures around the base.

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There are some other mulgas, some with complex and interesting minnirichi (red vertically-curling) bark that would repay close attention from our Adelaide friends.

In general, I would say don't prune too hard when you repot, give a bit more root space than usual, and go for the arid-zone species. Lots to recommend.

Gavin

[Rory]

And when you also finally get the shits from Acacia dying after rootwork, or just plain dying.... relent and try a Phebalium.
They are the strong antidote for Acacias.

But I’d love to see some Acacia progressions of your material.

I love Acacias as trees, mainly for their floral displays, but for me they were just too temperamental and would sulk or die if I looked at them wrong.

[EdwardH]

Rory I am curious re your comments on Acacia's and Eucalypts (another post). You have consistently stated that your conditions are very extreme: down to 1hr direct sunlight during the winter months, myrtle rust and hairy hungry beasties (possums, wallabies etc.). I recall a number of your experiment posts where you raved about many euc species yet now you seem to have had a change of heart. So how much of your seemingly anti acacia/eucalypt sentiment is influenced by your pretty extreme conditions and how much by simply experimenting? Remember when we experiment we do things to see how a species responds not knowing the result.

[Rory]

Rory I am curious re your comments on Acacia's and Eucalypts (another post). You have consistently stated that your conditions are very extreme: down to 1hr direct sunlight during the winter months, myrtle rust and hairy hungry beasties (possums, wallabies etc.). I recall a number of your experiment posts where you raved about many euc species yet now you seem to have had a change of heart. So how much of your seemingly anti acacia/eucalypt sentiment is influenced by your pretty extreme conditions and how much by simply experimenting? Remember when we experiment we do things to see how a species responds not knowing the result.

From all the wattles I tried, I often lost them soon after a repot which included root removals. I’ve never been a big fan of them as bonsai for this reason. Many would survive a repot and others wouldn’t. But most of the time with the repots they just would cark it after the 2nd or 3rd root removal.
I had experimented with wattles before I had myrtle rust (or at least knowingly been aware of myrtle rust).
If I forgot and let them get dry they usually wouldn’t survive. I didn’t find that wattles were heavily attacked by wallabies or possums so much, but I just found that even with nursery bought stock I didn’t have much success with wattles.

With Eucs it’s a very different story. I no longer have possum or wallaby issues, as that has been addressed. The sun levels gets low for about 6 weeks in winter yes, but other than that we have removed a massive number of trees from our backyard and thus all my trees are now in optimal health since the opening of sunlight thank goodness. We still have gums around but nothing like the issues we had 10 years ago.

Since having Gums in excellent health now, I can confidently say that they thrive in our conditions. The only exception is gall wasps which affect early everyone I know. Anyway, the issue with Eucs as I stated in that thread was ONLY die-back. It’s the one issue I’ve never been able to confidently predict when cutting them back. I’ve also had problems with root removal with Gums that were in excellent health which would then suffer die back moths later for no apparent reason.
I still adore them. However it can be very hard to predict how a gum will react to having branches cut back. In particular with gums, I usually don’t cut back twiggy growth anymore for this reason and only cut back branches that are about 0.5 cm thick.
Again, I highly recommend Eucs to everyone, but you have to accept that they can be temperamental with die-back. Mike has mentioned this in the past, and you don’t usually notice how much it can affect them until you hit the reduction and dwarfing stage of eucalyptus bonsai. It’s usually not such an obvious issue in the development stage as you aren’t refining the bejesus out of them yet.

Banksia on the other hand is a tree which I’ve not seen Gavin try his hand at much, and this was a funny message to him to try and encourage him to grow more Banksias, as when you cut back a healthy banksia, most species nearly always shoot directly from the cut without any dieback.
I know exactly how he felt in this post becasue I’ve had some fantastic Euc material and after branch reduction have had the most heart breaking die back issues.

[GavinG]

As I said in the Euc thread Rory, I've killed every Banksia (and Grevillea, DAMN AND BLAST!) that I've tried. I'm realising that I treat pretty much everything as if it's a Chinese elm - hard cuts both ends at the same time - which in retrospect is probably not wise...

Gavin

[Rory]

As I said in the Euc thread Rory, I've killed every Banksia (and Grevillea, DAMN AND BLAST!) that I've tried. I'm realising that I treat pretty much everything as if it's a Chinese elm - hard cuts both ends at the same time - which in retrospect is probably not wise...

Gavin

If it was Banksia marginata I can understand why. That is not an easy material to attempt bonsai life with. There are definitely species which are easier to grow. If you do give another go, I’d say don’t use any liquid fertilizer on Banksias, and stick to slow release fertilizer. I’ve got a Banksia integrifolia with your name on it next time I’m down in Canberra for you buddy. I’ve also got another Casuarina with your name on it if you’d like to try it.

Banksia integrifolia ’sentinel’ is one Id highly recommend for you. Tolerates a very heavy removal both on top and bottom, and has no problem with horizontal branching. Don’t use liquid fertilizer though, and keep plenty of foliage. It has much smaller compact leaves compared to integrifolia and develops lovely aged bark. I also have one here for you if you want to give it a go too.

Grevillea is not a tree I’ve tried my hand at much. I’ve only tried a handful of species, but just didn’t really develop a love for them and just gave my attention to other Genus. There were definitely some with lovely foliage, but I found them not as hardy as other Genus for root reduction that I chose in favour of Grevillea.

I hope you are well Gavin. And sorry about your Euc and your wattles that didn’t make it... I know how heart breaking it is.... but what I Iove about you is your optimism. My god you need it with this hobby. Haha

Acacia howitii was one I did love though. It was quite hardy and would grow easily and tolerated root reduction well. But by memory you had to shape them quickly otherwise once they harden, you need a chainsaw to style them. They were constantly eaten, but now that I don’t have vermin, they would grow easily. But I already have too many weeping varieties to look after.