Fertilizer for Acacia maidenii?

[kapitän kamasutra]

I have two maidenii seedlings growing in a pot since 3 years.

They grow a bit slow and the foliage stays rather small.

I think the main problem is the short grow season here, but i wonder if I could help them with some ferts?

Its my first Australian native plant, I'm not sure how much i should give them. I guess only a little dose?

low nitrogen?

Edited July 21, 2013 by spined

[Chrissy Star]

Hi! I had 10 madenii which i grew from seed. I gave them very little care for the first few months, maybe up to a year - I pretty much left em for dead. So one day i did get round to em and found that 4 were still going. It has been around 2 years now and they really started to take off when I replanted (gave more root space) and fertilized. I have found they are very hardy with fertilizer and react quickly and well (dark green, glossy & wide leaves). I use EcoWeed (Seaweed fert) & hydroponic nutrient. My bf had a good point about whether to treat Aussie natives with fertilizer or not...he reckons that just because a plant can exist in low nutrient soil doesn't mean that it wouldn't appreciate a good dose of em...and this makes sense - we live on(in) a boom/bust land where there is little water and nutrient for long periods, followed by excessive water and nutrients sporadically. The plants boom in the boom times and tolerate the bust times. So fert on, I say!!!

Edited July 21, 2013 by Chrissy Star

[Change]

Looks to me like its ready to go in the ground.

[Yeti101]

In my experience once they are in the ground they will need very little fertilizer.

[planthelper]

most fertilizer would be toxic to maiden and other acacias, I think to remember they hate phosphorous, so you have to either, fertilize in very small increments, if you use a normal fertilizer,

or use a, fertilizer suitable for acacias!

something like, NPK of 17.9 : 0.8 : 7.3

a native Australian plant fertilizer.

Edited July 22, 2013 by planthelper

[paradox]

you can get that australian native osmocote.. pretty general stuff but should be fine..

if you ensure suitable rhizobium bacterial inoculation when they're tiny seedlings they can more or less take care of their own nitrogen needs. mix into your potting mix some soil from underneath the trees you got the seeds from, or if you can't do that get some soil from underneath healthy native acacia's of similar species that may (or may not) have similar bacterial associate species.

[incognito]

3 years? They are potbound. Maybe try bonsai??

[Sallubrious]

The phosphorus sensitivity has been vastly over exaggerated for most Acacias. Some are very sensitive to phosphorus but some can tolerate a good dose and others are mid range and can do with some phopsorus in the mix.

A lot the problems with phosphorus is related to super phosphate which can be a bit of a time bomb in some soil mixes as people tend to add way too much, soluble phosphates can be safer (depending on the seasonal factors and application rates)

I found this webpage one time which details the sensitivity of many Acacias and other Australian natives to phosphorus. Unfortunately maidenii is not on the list. If you read it you will see many Acacias love phosphorus.

http://anpsa.org.au/APOL8/dec97-4.html

I have fed my potted maidenii's with miracle grow (the old high phosphate one @ 15:13:12 NPK) several times and they seemed to love it, just don't overdo it.

Really though the best thing for an Acacia is to get it planted in the ground in a suitable site.

Edited July 23, 2013 by SallyD

[kapitän kamasutra]

Very helpfull, thank you!

When i planted I gave them rhizobium by mixing in soil from a native legume, hoping they are symbiotic. the soil is a mix from this old potting soil, grit and loam, drains easy.

The pot is about 40 cm high, I hoped its enough depth for the roots to grow the plants to a high of about one meter.

If they are allready rootbound i might really have to try bonsai, winter is to cold and to wet here to plant them in the ground I believe.

I plan to put them in big containers at some point, but this might take one or two years, I hope to keep them alive till then.

I'll try a carefull dose of 3-2-3 tonight, I hope they like some P.

I did not know that phosphorous is toxic to so many Australien plants, maybe this is how I lost my eucalyptus seedlings.

[Pinion]

Charlie Carp half-strength is tolerable for natives, though personally I very, very rarely fertilise mine. However, 'Trees for Life' advises growers to add a granular, controlled-release fertiliser to the potting soil.

[obtuse]

These are australian plants and adapted to Very low nutrient levels, i.e low phosphorous, and low nitrogen.

In fact as Fabaceae they form nodules in order to gain their nitrogen from soil bacteria.

Im pretty sure, and maybe some-one can confirm, that they also form symbiosis with arbuscular-mycorrhizal fungi (AMF) in order to sequester phosophorous. I know in the case of other Fabaceae that the formation of AMF is essential in order to provide enough phosphorus for the formation and maintenance of the nodules, but also phosphorous and micronutrients for the plant. This is why high phosphorous and high nitrogen fertilisers can be toxic. The australian osmocote is perhaps a good idea, but put them in the ground and they will take off, just be careful not to disturb the roots too much.

Eucalyptus are also symbiotic with AMF for part of their life, before becomming ectomycorrhizal, so again phosphorous is toxic to the AMF and will result in impaired growth.

BTW, love the use of the olive oil can, i should do the same thing.

Edited July 25, 2013 by obtuse

[theuserformallyknownasd00d]

i have a maidens wattle off a member here, i havent even watered it and its been potted up twice since feb! now its only 1ft high but has engulfed a 200mm pot and needs to be put in the ground come spring!

ive grown a few from seed now and some just rocket, others just die. i think original genetics would play a huge roll with acacias and the ability to rock n roll straight from the seed coat... or maybe seeds that have been excessively treated before sale are the ones that are weak, and the natually collected ones from private collections are stronger.. i dunno.. this year i should keep some statistics..

[Bert&Ernie]

Best thing for Aussie natives is lots of root space..

[Stillman]

my 3 year maidenii is 4metres tall and covered in seeds right now. That needs to go in the ground or in a 200litre pot. It will take about a year to get over being kept in a seedling pot for so long.

[Nother]

Greetings all! just a quick note from personal experience with fertilizers. I would recommand Seasol and Powerfeed even to native varitities! Start with a small dilussion and work your way up. With natives its very touch and go all depending on the type of plant itself and not the species. I live on a nursry and give a huge varitity of natives the same doeses thoughout different growing periods. Some can handle it and others don't. The ones that dont like it or are sensitive get ripped out!