Haver many orchid fertilize emphazie to be urea-free?

[Louis_C]

I saw so many fertilizer emphasize to be urea-free. In Grow-More orchid ferilizer have both urea and urea-free fertilizer. What role of urea play in the world of orchid. Dose it cause any damage.drawback to orchid?

Thank you

[King_of_orchid_growing:)]

Many sources cite the advantages and disadvantages of using urea on orchids and other plants.

For simplicity's sake, urea needs soil microbes to break it down to a nitrogen source that epiphytes can use. pH also affects the bio-availability of urea based nitrogen as well.

However...

Apparently, Phalaenopsis can directly utilize urea based nitrogen into their roots. There was scientific research done on this and an article written about it. You can google scholar it and be the judge of what you think about the outcome of this particular subject.

There's plenty of stuff written about this. Just peruse the myriad of peer reviewed scientific articles or whatever kinds of growing guides about orchids there are on the web.

[Louis_C]

I heard that urea take a year to breakdown. They told me it better to use as a foliage fertilizer.

[King_of_orchid_growing:)]

Originally Posted by Louis_C

I heard that urea take a year to breakdown. They told me it better to use as a foliage fertilizer.

One year seems pretty long...

Here are some articles:

Fertilizer Urea

Agriculture: Urea Fertilizer in Crop Production

Keep in mind, they're talking about the length of time it takes for urea to break down under certain conditions in soil.

If your orchid is not grown in soil (most orchids commonly sold are epiphytes, although there are actually quite a few terrestrial/semi-terrestrial orchids as well), then urea nitrogen doesn't start breaking down. Therefore, it just washes away by the time you water your orchids.

Maybe the person who told you that urea based nitrogen in fertilizers can last up to a year is saying this in the context of how long it can stay inert when the conditions for break down are not met.

Ammonia or nitrate based nitrogen is readily used by all orchid genera and species.

[Jerry Delaney]

Apparently, Phalaenopsis can directly utilize urea based nitrogen into their roots. There was scientific research done on this and an article written about it. You can google scholar it and be the judge of what you think about the outcome of this particular subject.

I just wondered if you were referring to an article a number of years ago by Fred Bergman? I haven't used urea containing fertilizer for a number of years. I still wonder King, just what %age of orchids over the years were, and still are, grown using Peters 30-10-10 where the vast majority of the nitrogen available was in the form of urea.

[King_of_orchid_growing:)]

Originally Posted by Jerry Delaney

I just wondered if you were referring to an article a number of years ago by Fred Bergman? I haven't used urea containing fertilizer for a number of years. I still wonder King, just what %age of orchids over the years were, and still are, grown using Peters 30-10-10 where the vast majority of the nitrogen available was in the form of urea.

No, this article was written by a series of scientists (Martin Trepanier, Marie-Pierre Lamy, and Blanche Dansereau). The title is Phalaenopsis can absorb urea directly through their roots. It was received on June 25, 2008. Accepted November 25, 2008, and published online December 20, 2008.

But Fred Bergman's article in 2002 was cited as a referrence.

As far as the Peters 30-10-10, I don't know. I've adopted using non-urea based fertilizer from growing Bromeliads.