13 replies to this topic

[Richard Bunn]

Hi everyone.  

I've a question about my Baby Bio orchid fertiliser which is quite weak (NPK 5.3:2.2:0.8)

Rather than me typing again I think you'll get the gist of what my question is (can I use more for a higher strength?) from a reply I made to someone else just now:

Quote

Regarding feeding; I was just going through Peter D'Amato's book The Savage Garden making a note of all the foliar feed details for different genera.  What he says for Cephalotus is spray once a month with full strength orchid fertiliser.  

BUT looking in another section of the book the orchid fertiliser he recommends (in the Darlingtonia entry) has a strength of NPK 20:10:10.  So it must be one with a higher nitrogen level obviously.

I have two orchid fertilisers (funnily enough, for orchids :)) both of them far weaker than this formula.  My Baby Bio one is a quarter strength of the nitrogen level and less of the P & K (which I assume doesn't matter as much, certainly not the K).

I assume I can just quadruple the strength of the dose.  So, my advice is to see what kinds of orchid fertiliser (it has no urea) you can obtain and check the NPK ratio on the label and take it from there.  

[Dicon]

The strength of the fertilizer is the ratio you mix it with water, as directed on the bottle, this is usually measured in PPM or micro-siemens, and can be optimally adjusted to suit the plants in question. The manufacturer will have worked out a safe ratio to mix with water to suit general feeding requirements and that is what they print on the label.

Generally speaking, Orchid feeds are high quality with good levels of micro-nutrients, however they are best fed weaker than instructed to be safe, but it is a fairly complex and broad subject.

It is not advisable to feed stronger than instructed on the label as this can do more harm than good. But to say for sure, you need a PPM meter.

CP's are generally quite sensitive and are better/safer fed weak.

[mobile]

Richard Bunn, on 27 May 2012 - 15:30 PM, said:

I've a question about my Baby Bio orchid fertiliser which is quite weak (NPK 5.3:2.2:0.8)

Do you intend to foliar feed with this? Is the nitrogen urea  based or urea-free?

[Richard Bunn]

foliar feed.  Google tells me it has Ammonium dihydrogenphosphate in it. Whatever that is.

[mobile]

The label should say. I don't know why, but the ROI analysis on fertiliser labels usually gives more details than the UK.

See here, with regards to urea based fetilisers: http://en.wikipedia....rea#Agriculture

[Richard Bunn]

The nitrogen is ureic nitrogen.  Plus I discovered I was reading the UK side of the label for NPK.  The Irish formula is 5.3-0.95-0.7

[Dicon]

Ureic nitrogen needs to be broken down (I think the molecules are too big?) prior to absorption so is no good for foliar feeding.
Orchid feeds such as Dyna-grow do not use ureic N.

[Richard Bunn]

Damn. Unfortunately we don't have anything else available over here.  Ireland is a pain for getting your hands on the right chemicals. I'm gonna have to do more hunting around and come back to the thread after.

[mobile]

I use Growth Technology Orchid Focus. It contains no ammonia or urea, with the nitrogen being nitrate based. It is available in many garden centres that sell orchids and via online stores.

[Richard Bunn]

I have a bottle of Orchid Focus but it's the Bloom one so it's probably not the best thing as I need the Grow one which I can't locate in the garden centres.  I also have a bottle of their orchid spray. Are you using 'Bloom' or 'Grow'?

[mobile]

I use Grow, but I think Bloom has similar nitrogen levels. To be honest, I wouldn't get too concerned about the NPK levels, as long as you get the dilution strength right. I too have read that urea nitrogen requires soil bacteria to convert, so maybe you'd be better with nitrate based. I don't think the brand you use will make much, if any, difference.

[Richard Bunn]

OK, so in that case if I increase the strength of my Orchid Focus 'Bloom' accordingly I should be in the same ball park nitrogen wise as Peter D'Amato says.

[gardenofeden]

no, don't increase the strength, dilute as directed or less

[Richard Bunn]

OK thanks Stephen & Mobile.