I planted a few seeds in a heated propagator and one of them germinated.

The seedling grew to maybe 1.5 inch and is not growing anymore.
It's in a small pot in the propagator with high humidity and temps between 25C and 30C (77F - 86F).

Is this normal for them to stall like this, or does it need something?

how old is it?

I haven't been keeping a log, but I reckon it sprouted 2-3 weeks ago.

Maybe it's not supposed to be bigger at this stage, but it struck me how quickly it reached that size (literally a couple of days), and did nothing since then.

mine are months old by now but they arent growing due to winter.
10cm (4 inch)

So it's a day length thing? OK, I'll wait patiently

Does it already have phyllode? Still the baby mimosa like leaves? Remember, it's not a tropical plant, it's from a mediterranean desert climate, don't keep it too humid/moist, it doesn't like that. Your normal room climate should do fine + some light during winter.

Here is 0ne(1) moar trick that you can try:

Burn a cotton wool ball and throw the ash into the water that you feed to him. Maybe he will think there was a bush fire (nutrients) and break dormancy/sleep? Some plants are programmed that way.....

Hi Jagube, has there been anything noteworthy of updating???

I've tried more acuminata seeds (maybe 30 or so) and all turned into mush.
The floribundas however germinated very easily and I have two small seedlings planted in the ground now fighting the slug war.

Might try the cotton ball sometime, but more likely next year.

Well best of luck with them....were usually fightin slugs too, but the gardens been left alone so far this year.....until now proly, lol.....and i still cant quite seem to get the picture posted in the right direction, but this is my lone sprout after i believe about 10 days already, or somewhere around there. So i kinda just been curious as to what i may or may not be doing that i should...thanks

@Jagube: did you think about sterilizing your soil, like you would do with the takeaway tek for cacti?

Also it seems to me that acuminata is not the fastest grower. I am living in a quite mild area and my 1 year old acuminatas are all not bigger than 20cm.

My half year old Acacia simplex are now like 40cm tall. They are much faster.

Its funny to read your experience because I had almost the opposite experience. I really had a hard time with floribunda. Had like 10 seedlings, and all died.

No, I might try it one day, but seeing how well my floribundas are doing, I don't feel strongly motivated to go back to the acuminata.

One of my floribundas, germinated maybe 3 months ago, and growing in the ground now, has 5 branches, each a foot long. It's growing more sideways than upwards, I wonder if that's because the slugs ate the single growing point, or it's just their natural growth habit.

The weather has been dry, hot and sunny (I'm in the northern hemisphere), the slug threat long gone, and it seems to thrive in these conditions. I hope it survives the winter.

When i read the thread again I am getting the feeling that it might be to wet for the acuminatas. But I managed to start 3 floribundas which are growing great and fast. Mine are growing more slim and tall not wide. But They have developed some side branches now so that might change. They grow much faster than all acacias I have seen growing.

The floribundas are some of the fastest growing plants in my garden right now.

Considering that their DMT content is roughly 1/3 - 1/2 that of A. acuminata narrow phyllode - arguably the 'best' Acacia, and that their growth rate is several times faster, they may be one of the best choices for a home grower aspiring to self-sufficiency.

I second that. The next fastest in my opinion / tested so far is Acacia simplex.

I gave accuminata a shot but the moderate cold in my area (zone 7b historically but 8a recently). It did not make it. I think the seeds over to a plant friend in a warmer area.

Now I'm looking for a good acacia that can survive some cold.

One thing about many Acacias is often overlooked. They evolved to only sprout in the wake of brushfires. Smoke contains butenolide compounds that break seed dormancy in a wide variety of plants adapted to wildfire prone areas.
I have a jar of 'smoke hormone mix', I think my current mix is sage, oregano, and mexican oregano but you can just use any non-toxic deserty plant. I smoke a few puffs and bathe the seed in the smoke. I just did some acuminatas like that- nicked the fat end with nail clippers only enough to crack the seed coat, put in a jar 1/3 full of warm water, blew in some smoke, sealed and shook the jar, the next morning poured out the water and blew in some more smoke. After that the seeds were quite eager to grow. Now if I could only find my phlebophylla seed!
Other people use other techniques but its basically smoke + swollen seed = grow. It can be even more dramatic than a 0.5 or 1% potassium nitrate soak in some other plants (I just rescued some ancient and 'inviable' Lespedeza seed with 1% potassium nitrate).

I did my sow on my second set of ten. This time I put domes over them day 4.....

The same came of mine, sprouted late spring and grew a little through the summer. Unlike mimosas which I had no problem with, the acuminatas never grew more than a few inches. There was plenty of heat, light and humidity and I used the same soil mix. Baffled

They like dry heat and very well drained soil.

I'm in the tropics here and would not even consider trying to grow them, just because I don't want to subject myself to the frustration.

I forgot that I gave one to a friend to look after, in very different conditions. It's thriving! Only the friend has grown attached to it so I'll have to try again next year. No biggie, now I know.

It seems...



...this is true!