Acacia maidenii troubles, bright red leaves

[Happyconcacti]

Hi All,

I have 2 Acacia maidenii in the ground, they're about 1.5 meters tall now.

Trouble is that the leaves are bright red. I thought it was a Phosphorous deficiency so I added a bit to the soil. It hasn't seemed to help much.

Right next to the maidenii I have 2 Acacia acuminata v. narrow phyllode and they're doing great, bright green growth even with the cooler temps recently.

Any suggestions? I don't know what to do.

Thanks,

[Change]

Maybe posting a picture would help

I think red tips on the leaves can be normal at certain times of the year, but im no expert

[ghosty]

normal.

[Sallubrious]

Is it on the new growth or on the older phyllodes ?

Maidenii goes through various stages of pigmentation quite often, it's just a normal part of it's growth cycle. It's most probably just caused by different levels of pigments chlorophyl and anthrocyanins. New phyllodes can start with a red/purple tone before an appreciable amount of chlorophyll builds up and older phyllodes can look that way when the phyllodes have almost reached the end of their useful life and stop producing chlorophyll.

Anthrocycanins are in many ways protective pigments, without them many plants would not survive.

[ghosty]

nice Sally, thanks.

[HolographicYou]

Careful when giving our natives phosphorous, they are EXTREMELY efficient at picking it up and often a regular dose is too much for their hairy roots.

[ghosty]

i give my mainedii phosphorous every so often, when they show very dark green leaves. they dont mind it at all, in fact, they seem to love it.

Holographic, can i ask what natives in particular you have noticed a problem with? I'm sure there are many.

[HolographicYou]

I havent personally ever used phosphorous on my natives (acacias) just because they really can get by on close to none.

And ive been too afraid I will freak out those sensitive roots!

But with careful application im sure phosphorous could give a nice boost.

[Sallubrious]

A general rule of thumb with Australian Acacias is to keep the levels of phosphates low, but in my experience that 's much more important for species from arid areas with a minimal phosphorus cycle. Coastal Acacias like maidenii can tolerate more phosphates without problems because they've evolved in a zone with phosphates.

I tortured some miadenii sapling in pots for a few years before I finally got around to planting them out and now they are nearly fifteen feet tall after being hacked down at least 5 times. I fed them miracle grow at full strength many times as an experiment and the took it in their stride.

I wouldn't put additional phosphorus on the acuminatas though as they come from an arid low phosphorus zone and most likely wouldn't tolerate it very well.

Some of the proteas and other South African species will drop dead from the smell of phosphorus.

[ghosty]

"I wouldn't put additional phosphorus on the acuminatas though as they come from an arid low phosphorus zone and most likely wouldn't tolerate it very well."

please allow me to amend this. i have two normal acuminata (in pots) and have given super phosphates to them. no problems. as with sandpaper wattles, mulga's, oxycedrus, and others. still no problems. i am wondering what few do actually have issues with it.

has anyone actually had issues with phosphates and wattles? if so, what wattles, and what form of phosphates?

[Sallubrious]

I have some acuminatas and obtusifolias planted in an old garden bed that's had regular doses of blood and bone (the season before the Acacias were planted) and they are doing well too.

I think a lot of the hysteria came from Australian wild flower nurseries that were also growing Proteas and Banskias and they've extrapolated the phosphate problem from that.

That being said I did find a website years ago that listed different species of Australian Acacias and their phosphate tolerance. I posted a link here years ago but I couldn't be bothered looking for it now.

It would be good to see some scientific research into the matter to see if phosphorus good bad or ugly for some of the species we deal with here.

I think a lot of it is B.S.

Edited November 22, 2015 by Sally

[Happyconcacti]

Hi everyone,

thank you for all the replies and information!

I'll get pictures posted in the next day or so.

Thanks,

Hcc