Fertilizers for Aussie orchids

[keithrs]

I was wondering what fertilizers you guys use for Aussie orchids? I was thinking about using DUNO fertilizer but cost to much to ship.

[WhiteRabbit]

I have two Australian Dens (kingianum, and bigibbum), both get the same fert as my other orchids ...
(orchid or bromeliad fertilizer)

[keithrs]

Ya, thats what I do. Just alittle stronger than the rest.

I was talking to a gentleman at my orchid society meeting and he told me to use low to no N fertilizer but high K and they will flower better. DUNO has a special fertilizer they sell for native orchids. So, I wanted to try it on my Aussie orchids, since I have so many. But cost to much. Other recommend peters excel Hi K but I can't find it anywhere here(in the us). So, I'm really looking for a high K fertilizer. I should of bought it at the SB show.....

[Baz in Oz]

I don't think it really matters what fertilizer you use as most of the orchids grown down here are exotic types.
Oz soils are generally deficient in phosphorus so low 'K' fertilizers may be the go for terrestrials originating from here but not many of them are in general cultivation anyway.
I tend to use any commercially available complete product. At the moment, I am using what I believe are 'Peters' products, a 'grower' and a 'finisher' which is higher in potassium. I use the 'finisher' every fourth application.
I believe my 'kill rate' is about average.

Baz

[WhiteRabbit]

oh - I see!
I have some Wonderlizer High Bloom fert, 6-25-25 - I actually now usually only use this mixed with the 'high growth' Wonderlizer 25-9-9 to balance them both out, so I guess if you want to go with the high K fert, look for a 'bloom booster' fert - Dyna-gro has a bloom formula, liquid 3-12-6
Being that Baz is in Oz, I definitely defer to his knowldege

[Stefan]

i find any slow realease fert will do, but be careful, aussie natives dont like too much fert, so twice a year would be fine in my opinion

stefan

[keithrs]

Thank you guys for your responses......

After talking to this gentleman who grows mainly Aussie orchids. He told me that high N will lead to long thin weak growths with Aussies. But the extra K will make the plant stronger, more resistant to drought, flower better.

I never had problems with mine.....except with my last speciosum which had root rot when I received it but recovered well.

Just wanted to try it for a while to see if I like it or not.... I guess I have to find a good bloom fertilizer... and suggestion?

[tucker85]

I've read that plants will take whatever nutrients they need from the mix that's available to them. During the longer, brighter days of the spring and summer months orchids are growing rapidly and need plenty of nitrogen. In the fall when the days grow shorter and there's less light reducing nitrogen would make sense. They used to think that high levels of phosphorus in the fall would encourage blooming but now they think that reduced nitrogen before the blooming season is what induces blooming.

[keithrs]

From what I got from the conversion is that excessive "N" in Aussie Den.'s will make your plants grow "big" but will give you "weak" growths and the flower count will be lower. He told me that "K" builds stronger growth through stronger cells and maximize photosynthesis(SP?) to give you better flowering.

Anyway, I went to my local hydroponics store down the street and several companies make a Potassium magnesium sulfate additive to be used with a balanced fertilizer. Most are 0-0-22, and used for flowering and tuber growth. Not badly priced but I want more info before I buy some. Plus I need to get my shade house build before I start another project..... Not like I have 50 million projects to finish anyway....LOL

[harleymc]

My fertalizing is very approximate- I realized with the soluble ferts that they can absorb atmospheric moisture so that weight based is inaccurate- I just use measuring spoons for mixing.
The large majority of my orchids are the cool growing/spring flowering Dendrobium species and hybrids, with a few hybrids with D Biggibum (warm growing autumn flowering).
I couldn't find a soluble off the shelf low N fert so I mix my own.
Summer - 50/50 mix of 'Thrive' (NPK 23:4:18) to which I add Potash 0:0:41, a tiny pinch of trace elements and seaweed emulsion.
Winter - No Thrive, only the Potash, traces and seaweed.
Despite being really stingy with the Nitrogen the cooler growing species and hybrids will throw out the occasional new growths in winter, which makes me wonder if we get a bit too tricky and clever with our fertalizing regimes.