It looks like it could work. I'd be tempted to drill a series of holes around the lower part of the tube to allow a bit more air exchange. If the bottom few inches of the tube are filled with rubble then that should prevent it from becoming anaerobic.

You might need to find some way to give some extra support especially when the trees get a bit bigger. I imagine they'd blow over in strong wind.

Is the potting mix a low phosphate mix suitable for Australian native plants ? I would advise you not to use regular or even premium potting mix because of phosphate levels.

I've found acuminata to be only mildly phosphate tolerant. I potted up a batch of acuminata seedlings last year when I didn't have much native potting mix on hand, so I mixed the native mix I had with about 50% standard potting mix and most of the seedlings died. So be careful with standard potting mix, it just has too much phosphorus for many Australian Acacias.

As a general rule with Acacias, the drier and more arid their natural growing zone is the more phosphorus sensitive they tend to be. Many Acacias endemic to coastal zones that typically see more annual rainfall can tolerate much more phosphorus but it's always wise to play it safe and keep the phosphates to the bare minimum.

Thanks so much - that's some GREAT information!

Unfortunately, I got ozmocote premium potting mix, damn. But the good news, I haven't filled it up yet. I'll see if I can take them back and swap them for low phosphate potting mix.

I've got the support issues sussed. These are either going to pop out of the bottom of a elevated porch, else I will replace with steel mesh with the same structure.

Latest germination test with Acuminata (narrow var) - these are not as easy to germinate as the broad phyllode variety of acuminata

GroupA) 10 seeds, boiling water soak for 1min
GroupB) 10 seeds, boiling water soak for 1hr
GroupC) 10 seeds, boiling water soak overnight

Seeds were treated on 27th/April/2014 and planted in soil, 100% humidity, 28C

As of 8th/May/2014, 2 have sprouted from GroupA (will update if more sprout)

This is actually what I am expecting.
When using the boiling water method, generally plants with smaller seed only need soaking of no more than 1 hr, where the larger seeds can be soaked overnight (up to 24hr)

Last pic is of my acuminata broad. Notice how one of the small leaves has very phyllode properties. It must be result of stress being transplanted outside

One thing, regarding watering. When growing in pots especially, regular light watering will discourage the tap root growing down. On the other hand, watering less often (with larger doses of water) and allowing it to dry out a little, will promote the tap root to grown down deep.

Have fun!

Nice looking plant Shadow!

Did you get any more to germinate and do you remember which group those that did came from ?

Of all the Acacias I've grown the narrow phyllode acuminatas seem to have the lowest germination rates - besides phlebs but that's another story altogether. I've sown hundreds of acuminatas over the years with mixed success.

Along the lines of what you stated about the soak times, I've come to believe that moisture levels are critical for successful germination of acuminatas particularly the narrow phyllode species. Too much moisture and many times they just don't germinate.

There's been several times when I've planted a few hundred normally in a soil mix(after a boil and soak) only to have a few germinate. It sucks to prepare a full tray of seedling tubes only to have a few come up.

My latest method to germinate them has been giving me great results. I spotted my Mrs using little round cotton makeup removal pads one time and wondered how they'd go if I tried to germinate the seed on them. So I tried it and now I average around 60% success. They germinate much better on the makeup pads than they do on damp paper towel, I find that paper towel is too wet and at optimum moisture levels it's just about to dry out, so they either can dehydrate and die or stay too wet and rot. The makeup pads drain better and hold an optimum moisture level for much longer so for me they work much better.

I get a plastic box & cover the bottom with makeup pads and then wet them down, then I put the pre-treated seeds on them and then cover them with another makeup pad spray them down and put a lid on the box. You don't want any water pooling in the bottom of the box - if it does it's too wet.

I keep them at around the same temp as you too, because of the hysteresis of the thermostat my heatpad floats between about 26 - 29 degrees celcius.

I really believe that the boiling water tek can be detrimental to seed as small as narrow acuminatas and some get killed by the hot water. I'd nick them and soak them but I really couldn't be bothered to mess around nicking heaps of tiny seeds, so I just use the hot water.

Interesting. Actually, I'm glad u brought that up, the soil this time around was a little damper than I usually have it.
No more germinated!

I'll try that method with the cotton pad's. I use the same ones you are talking about, they're a round disc shape. I used them before to do A. Oxycedrus but didn't get any success rate, and that was after they had an overnight boil and were visibly swollen, but they didn't sprout open. However I did have good success with planting them straight into soil after a hot water soak.

I think the acuminata narrow seeds need to be planted a little deeper than 5mm into the soil. The two that have sprouted are to tall for their own good. They're standing 5-6cm above soil and still haven't popped their seed hats off

I'll try that method with the cotton pads for those as you've pointed out. If it's a pretty consistent result, I'll specify it in the wiki
Thanks Hieronymous - you're certainly a 'go to' guy in this particular field

I'm having difficulty with acuminata (narrow phyllode), but not with floribunda.

Out of the 12 or so acuminata seeds I sowed, only one germinated (and eventually died). Of the floribunda I only sowed 4 seeds a few days ago and 3 of them have already sprouted.

I treated both types with boiling water. The acuminatas floated all the way, the floribundas sunk straight away. Could my acuminata seeds be bunk?

Try chucking the acuminata seeds in the boiling water again.

Sometimes it takes a few goes!


Exposing them to smoke might help.
Also, a ripe banana (ethylene).

Still no luck with the acuminata, the seeds either dry out, get furry mold on them or turn into mush.

Of the 4 floribundas that germinated, two have survived and seem to be doing well. The other two struggled to get their roots to penetrate into the growing medium, and eventually perished.

Not sure how to expose the acuminata seeds to smoke. I've tried that on my Salvia apiana seeds by putting them on a spoon and holding it above a burning incense stick, but don't think they got much smoke that way.

Spider mites!!!!!

Acuminata narrow leaf

I’m attaching photos of 6-month-old Acacias grown from seed.
A. floribunda
A. acuminata (broad phyllode, narrow phyllode, small seed)
A. burkittii

My experience so far is that A. floribunda grows much faster and is much more resilient than A. acuminata.

Far from being an expert grower, but I can say that amount of sunlight seems to be the biggest factor affecting growth rate.

A. floribunda, if high DMT content is confirmed (especially if it's confirmed in young plants), may be a more viable candidate for self-sufficiency than the best Phalaris strains, including AQ-1. It grows like crazy.